A centralized highway information dissemination system based on wireless networking

Abstract

This invention relates to the field of highway information board publishing technology, and more particularly to a centralized highway information publishing system based on wireless networking. The system includes: an event detection module that maps the highway network to a mileage axis curve, determines the impact length based on event type, and dynamically updates the impact range based on the start time, an effective time window, and attenuation stages; a link status monitoring module that extracts statistical features of the communication status and classifies link quality into different health states; a publishing distribution module that determines publishing eligibility based on impact distance and health state, and executes corresponding publishing strategies accordingly; a feedback module that generates a publishing effect curve based on receipt information for dynamic correction; and a consistency verification module that ensures consistency in the displayed content of adjacent information boards by comparing content summaries, timestamps, and self-checking parameters. This invention achieves adaptive matching of event impact range, dynamic coordination of link quality and publishing strategies, and autonomous link failure management.

Description

Technical Field

[0001] This invention relates to the field of highway information board publishing technology, and in particular to a centralized highway information publishing system based on wireless networking. Background Technology

[0002] Currently, highway traffic information dissemination primarily relies on roadside information boards that connect to a central platform via wireless networking to push real-time traffic information such as traffic accidents, construction and maintenance, and severe weather to passing drivers. Existing wireless networked information dissemination systems typically employ a central platform-centric distribution model with information boards passively receiving the data. The platform presets a fixed dissemination range based on the event location, and the information boards display the received information. However, in practical applications, the delineation of the event's impact range lacks adaptability to traffic flow propagation patterns. Existing technologies often use fixed radii or static station intervals as the dissemination range, failing to consider the asymmetric differences in the impact length of event types on upstream and downstream areas, and neglecting to incorporate time decay factors after the event occurs. This leads to a mismatch between upstream warning distances and actual queue lengths, and a disconnect between downstream alert boundaries and on-site handling areas. Summary of the Invention

[0003] To address these issues, the present invention provides a centralized highway information dissemination system based on wireless networking, which overcomes the technical problems in the prior art such as mismatch between the scope of information dissemination and the actual impact of events, poor dissemination reliability due to fluctuations in wireless link quality, inability to maintain basic services when the link is lost, and inconsistency in the content displayed on adjacent information boards.

[0004] To achieve the above objectives, the present invention provides a centralized highway information dissemination system based on wireless networking, comprising:

[0005] The event detection module is used to collect event information from various road segments in the highway network and map the highway network as a mileage axis curve to determine the distance and directional relationship of the event's impact on each information board; the event information includes event type, event location, and start time.

[0006] The link status monitoring module is used to obtain the link status indicators of the information board, and determine the health status characterization parameter group of the information board based on the link status indicators, so as to determine the release health status type of the information board.

[0007] The distribution module is used to determine whether each intelligence board is qualified to publish events based on the influence distance and direction relationship; and to execute differentiated publishing strategies according to their publishing health status type, wherein the publishing strategies include full-scale real-time strategy, transmission optimization strategy and autonomous publishing strategy.

[0008] The feedback module is used to collect feedback information from the information board, generate a release effect curve, and dynamically correct the influence distance and direction relationship in the event detection module based on the deviation between the release effect and the benchmark value, as well as adjust the adjustment content and amount for sub-health status.

[0009] The consistency verification module is used to verify the consistency of the displayed content of adjacent information boards. The consistency verification includes comparing the display content summary, timestamp and self-check parameters of adjacent information boards to determine whether there is any abnormality in the displayed content.

[0010] As a preferred technical solution for a centralized highway information release system based on wireless networking, the event detection module maps the highway network into a continuous mileage axis curve in mileage order, projects the event location onto the mileage axis curve to obtain the event mapping point, and uses the event mapping point as a reference to determine the upstream influence length and downstream influence length along the upstream and downstream directions of the mileage axis curve in combination with the event type.

[0011] Specifically, for any information board, the influence distance and direction relationship of the information board relative to the event are determined based on the mileage difference between the position of the information board on the mileage axis curve and the event mapping point, as well as the upstream influence length and the downstream influence length.

[0012] As a preferred technical solution for a centralized highway information dissemination system based on wireless networking, the event detection module determines the effective time window of the event based on the start time in the event information, and updates the influence distance and direction relationship based on the effective time window.

[0013] As a preferred technical solution for a centralized highway information dissemination system based on wireless networking, the link status monitoring module acquires the link status indicators of the information board within a preset monitoring time window. The link status indicators include the number of lost heartbeats, round-trip time jitter, and packet loss rate. Statistical features are extracted from each of the link status indicators to obtain the corresponding indicator feature values, and the health status characterization parameter group is integrated and output.

[0014] As a preferred technical solution for a centralized highway information release system based on wireless networking, the link status monitoring module classifies the release health status type of the information board based on the health status characterization parameter group. The release health status type includes three categories: normal status, sub-healthy status, and disconnected status.

[0015] The health status characterization parameter set includes heart rate loss feature value, round-trip time jitter feature value, and packet loss rate feature value.

[0016] If all indicator values ​​meet the normal threshold range, the state is judged as normal; if at least one indicator value exceeds the normal threshold range but does not meet the chain break judgment condition, the state is judged as sub-healthy; if the heartbeat loss count characteristic value reaches the chain break threshold, and / or the continuous heartbeat loss duration exceeds the chain break duration threshold, and / or the packet loss rate characteristic value reaches the chain break threshold, the state is judged as chain break.

[0017] As a preferred technical solution for a centralized highway information dissemination system based on wireless networking, the dissemination and distribution module is configured to: for any information board, obtain the influence distance and direction relationship of the information board relative to the current event;

[0018] If the influence distance is less than or equal to the influence length corresponding to the directional relationship, then the information board is deemed qualified to publish the current event.

[0019] As a preferred technical solution for a centralized highway information release system based on wireless networking, the release distribution module is further configured to, in response to determining that an information board is qualified to release information, allocate a corresponding release strategy according to its release health status type.

[0020] If the published health status type is normal, then the publishing strategy is a full-scale real-time strategy, which publishes the original content of the event information in full and in real time.

[0021] If the published health status type is sub-healthy, the publishing strategy is to activate the transmission optimization strategy, reduce the publishing frequency to a preset low frequency period, convert the event information to be published into a preset short text template or icon format before sending, and select the protocol stack with the least data load for sending.

[0022] If the published health status type is "disconnected", then the published strategy is an autonomous published strategy, which stops sending information to the intelligence board, and the intelligence board generates and displays a security prompt message based on the last trusted event in the local cache combined with a time decay algorithm.

[0023] As a preferred technical solution for a centralized highway information release system based on wireless networking, the feedback module calculates the success rate, release delay, and number of release failures of each information board within a preset time period based on the receipt information, and generates the release effect curve in the form of a time series.

[0024] The feedback module compares the release effect curve with the preset baseline curve point by point, calculates the deviation value at each time point, and generates a correction coefficient based on the judgment result that the deviation value exceeds the preset deviation threshold to correct the upstream and downstream impact lengths of the current event.

[0025] As a preferred technical solution for a centralized highway information release system based on wireless networking, the feedback module generates adjustment amounts and adjustment content for the sub-healthy state based on the deviation, and sends the adjustment amounts and adjustment content to the release distribution module.

[0026] The adjustment amount includes the increase or decrease of the value of the low-frequency cycle, and the adjustment content includes the adjustment instructions for the text length or icon complexity of the short text template, as well as the switching instructions for the protocol stack.

[0027] As a preferred technical solution for a centralized highway information release system based on wireless networking, the consistency verification module obtains the current display content of adjacent information boards, extracts the display content summary, release timestamp and self-check parameters of each display content, compares the display content summaries of adjacent information boards bit by bit, compares the release timestamps by time difference, and compares the self-check parameters by value.

[0028] If the displayed content summary is inconsistent, and / or the time difference of the publication timestamp exceeds the preset time difference threshold, and / or the self-check parameters exceed the preset self-check parameter range, then it is determined that there is an abnormality in the displayed content.

[0029] Compared with existing technologies, the beneficial effects of this invention are as follows: This invention maps the highway network as a mileage axis curve through an event detection module, dynamically determines the asymmetric upstream and downstream impact lengths based on event types, and introduces an effective time window and attenuation phase to achieve spatiotemporal adaptive updates of the event impact range; simultaneously, the link status monitoring module extracts multi-dimensional statistical features from heartbeat loss counts, round-trip delay jitter, and packet loss rate, discretizing the wireless link quality into three health states: normal, sub-healthy, and disconnected; the distribution and diversion module performs full-scale real-time execution based on a combination of impact distance and health status. The system includes optimized publishing and transmission strategies and an autonomous publishing mode. The feedback module performs closed-loop correction of the impact length and sub-health strategy parameters based on the publishing effect curve. The consistency verification module ensures the synchronization of displayed content on adjacent information boards through cross-comparison of content summaries, timestamps, and self-checking parameters. This achieves adaptive matching between the scope of information dissemination and the spatiotemporal evolution of events, dynamic coordination between link quality gradient and publishing strategy, local autonomy in link failure scenarios and seamless data synchronization after recovery, as well as consistency self-verification and anomaly isolation of displayed content on adjacent information boards. This significantly improves the accuracy, reliability, and continuity of highway information dissemination in a wireless networking environment. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the structure of a centralized highway information publishing system based on wireless networking, according to an embodiment of the present invention.

[0031] Figure 2This is a logic diagram illustrating whether an information board is qualified to publish events, according to an embodiment of the present invention.

[0032] Figure 3 This is a logic diagram illustrating how the information board assigns corresponding publishing strategies based on the health status type, according to an embodiment of the present invention. Detailed Implementation

[0033] To make the objectives and advantages of the present invention clearer, the present invention will be further described below with reference to embodiments; it should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0034] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0035] It should be noted that in the description of this invention, the terms "upper", "lower", "left", "right", "inner", "outer", etc., which indicate directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of description and is not intended to indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.

[0036] Furthermore, it should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" 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; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0037] Please see Figures 1-3 As shown, this is a centralized highway information publishing system based on wireless networking according to an embodiment of the present invention, including: an event detection module, a link status monitoring module, a publishing and distribution module, a feedback module, and a consistency verification module.

[0038] Specifically, the event detection module internally pre-constructs a mileage axis curve with highway mileage markers as nodes. Adjacent nodes are assigned continuous mileage coordinates through a linear interpolation algorithm, ensuring that any location in the highway network is mapped to a unique mileage metric. Assume the mileages of adjacent nodes A and B are respectively... and The distance along the road from position P to node A is The distance along the road to node B is The mileage coordinates of P are obtained through GPS coordinate calculation or path matching. Calculated using the linear interpolation formula:

[0039]

[0040] This formula uses linear interpolation based on distance ratios to ensure that mileage coordinates change continuously along the road. Using this method, a unique and continuous mileage metric can be obtained at any location within the highway network.

[0041] After receiving event information from the centralized publishing platform, the event detection module extracts the event location coordinates and performs spatial matching between these coordinates and the mileage axis curve. If the event location coordinates coincide with the coordinates of a certain mileage node, then that node is directly used as the event mapping point. If the event location coordinates are located between two mileage nodes, then linear interpolation is performed based on the distance ratio between the coordinates and the coordinates of the preceding and following nodes to calculate the accurate mileage coordinates and generate the event mapping point.

[0042] The event detection module also stores a mapping table between event types and impact lengths. This mapping table uses the event type as the index field, and each record contains two fields: a preset upstream impact length and a preset downstream impact length. The mapping table is preset through offline calibration, acquiring sample data of actual congestion queue lengths, controlled area lengths, and on-site handling ranges during historical events. Data is grouped by event type, and linear regression is performed on the samples within each group. The fitted feature length values ​​are rounded and written into the mapping table. In implementation, using the event mapping point as a reference, the event type of the current event is extracted. The mapping table is then searched using this event type as an index, and the corresponding preset upstream and downstream impact lengths are read and determined as the upstream and downstream impact lengths of the event, respectively.

[0043] Taking traffic accidents as an example, samples of the actual queue lengths formed during multiple typical accidents are collected, and the queue length values ​​of each sample are statistically analyzed. The 85th percentile is taken as the preset value for the upstream impact length. For example, in a scenario of a highway in a plain or hilly area, the calibration result is 2.0 kilometers, meaning that the actual queue length for 85% of accidents does not exceed 2.0 kilometers. Information boards within this range can provide early warnings to drivers about to enter the affected area. For construction and maintenance events, the upstream impact length is determined based on the minimum length of warning zones stipulated in relevant traffic engineering specifications, combined with the actual driver recognition distance from on-site investigations. For example, in a construction section with a speed limit of 80 km / h, the upstream impact length can be set to 1.6 kilometers. The downstream impact length corresponds to the spatial range or restoration zone boundary occupied by the event in the downstream direction. Its value is calibrated through statistical data on the on-site handling range. For example, samples of the actual closed section lengths of multiple construction and maintenance operations are collected, and the average value is taken as the preset value for the downstream impact length, such as 0.5 kilometers. This allows information boards within this range to inform drivers who have passed the event point of the road condition restoration status ahead.

[0044] The event detection module iterates through the list of currently online information boards, reads the preset mileage coordinates of each information board on the mileage axis curve, calculates the absolute value of the difference between the mileage coordinates and the mileage coordinates of the event mapping point, and records it as the mileage difference; it compares the size relationship between the mileage coordinates of the information board and the mileage coordinates of the event mapping point. If the mileage coordinates of the information board are smaller than the mileage coordinates of the event mapping point, it is determined that the information board is located in the upstream direction; otherwise, it is determined to be in the downstream direction.

[0045] In this invention, the spatially continuous highway network is compressed into a one-dimensional mileage measurement space, transforming the spatial relationship between events and information boards into a calculable and comparable numerical quantity—mileage difference. By introducing a mapping relationship between event type and impact length, the values ​​of upstream and downstream impact lengths correspond to the event's obstruction and propagation distance on upstream traffic flow and the event's spatial occupancy in the downstream direction, respectively. This achieves asymmetric modeling of the impact range, enabling the eligibility determination of information board issuance to reflect the actual propagation pattern of events in the road network topology. The upstream warning distance is positively correlated with the severity of the event, and the downstream warning de-emergency boundary matches the event handling spatial boundary, thereby avoiding invalid or missed warnings caused by unified issuance across long road sections.

[0046] Specifically, the event detection module extracts the start time field from the event information and obtains the event type of the current event. The module has a pre-set mapping table between event types and effective time window lengths. This mapping table uses the event type as an index, and each record contains a preset value for the effective time window length. The mapping table is pre-set through offline statistics, collecting samples of the duration of similar historical events from the time of occurrence to the time of resolution, calculating the average, rounding the statistical feature values, and writing them into the mapping table. In practice, the mapping table is looked up using the event type of the current event as an index, the corresponding effective time window length is read, and timed monitoring is started from the event start time.

[0047] The event detection module acquires the current system time at fixed intervals, calculates the difference between the current time and the event start time, and records it as the elapsed duration. The elapsed duration is then compared with the effective time window length: if the elapsed duration does not exceed the effective time window length, the current upstream and downstream impact lengths of the event remain unchanged, and the update process is not triggered; if the elapsed duration exceeds the effective time window length for the first time, the dynamic update process is initiated, entering the decay phase.

[0048] During the decay phase, the event detection module has a pre-set decay duration parameter, which is calibrated through a limited number of real-vehicle tests: acquiring various event types from history, continuously monitoring the cross-sectional vehicle speed recovery curve after the effective time window ends, and using the point where the vehicle speed recovers to 85% of its normal value as the decay termination point. The average value from multiple tests is then pre-set into the module. It's understandable that during the decay phase, the event has been resolved, but traffic flow has not yet fully recovered to normal levels. If event information is removed immediately when vehicle speed begins to recover, drivers may become complacent too early; if it's removed only when vehicle speed has fully recovered to 100%, the information may be too outdated. Therefore, using 85% as the decay termination point represents a critical state where congestion has significantly eased but has not yet fully returned to normal. Subsequently, a linear decay strategy smoothly reduces the affected area to zero.

[0049] Each cycle, the event detection module multiplies the current upstream and downstream impact lengths by an attenuation coefficient. The attenuation coefficient is calculated by subtracting the ratio of the exceeded duration to the attenuation duration from 1. This process continues until either the upstream or downstream impact length attenuates below zero. At this point, the event is marked as invalid and removed from the release eligibility assessment process. After each update cycle, the event detection module re-performs the intelligence board traversal assessment process with the updated upstream and downstream impact lengths, recalculates the release eligibility, impact distance, and directional relationships for each intelligence board, and sends the updated results to the release distribution module.

[0050] In this invention, the lifecycle of an event is divided into two stages: an effective time window and a decay phase. The effective time window corresponds to the core impact period from the occurrence of the event to its resolution. During this period, the scope of the event's impact remains stable, avoiding frequent changes in the information board's content due to communication delays or temporary fluctuations. The decay phase corresponds to the transition period during which traffic flow gradually returns to normal. A linear decay strategy is used to smoothly shrink the scope of impact, avoiding abrupt changes in the information board's content from being present to being absent due to the instant the event is removed. The effective time window length is preset based on the event type, so that events of different natures receive a release lifecycle that matches their actual resolution cycle. Short-term events are promptly removed, while long-term events are continuously released, thereby ensuring that the information board's content is always synchronized with the actual situation on site and preventing a decline in drivers' trust in the information board due to long-term retention of event information.

[0051] Specifically, the link status monitoring module acquires the link status indicators of the information board within a preset monitoring time window. The link status indicators include the number of heartbeat loss, round-trip time jitter, and packet loss rate. Statistical features are extracted from each link status indicator to obtain the corresponding indicator feature values, and the health status characterization parameter set is integrated and output.

[0052] In implementation, the link status monitoring module collects raw link status data for each information board in real time within a preset monitoring time window. The length of this monitoring time window can be dynamically configured according to the system deployment scale and wireless network environment. For example, in a highway trunk line scenario, it can be set to 5 minutes to ensure that the fluctuation characteristics of link quality are captured without masking real-time changes due to an excessively long time span. For each link status indicator, the link status monitoring module first performs data cleaning to remove outliers caused by momentary interruptions or occasional anomalies, and then uses a sliding window method to extract the statistical feature values ​​within that time window.

[0053] For the number of lost heartbeats, the module records the heartbeat loss count every minute, forming a sequence containing 5 sample points within a 5-minute time window. The average value and average deviation of this sequence are calculated, and the ratio of the average deviation to the average value is used as the indicator feature value of the number of lost heartbeats to reflect the degree of fluctuation in the number of lost heartbeats. If the standard deviation exceeds the preset fluctuation threshold, it is additionally marked as an abnormal fluctuation feature. This threshold is determined by statistical analysis of the heartbeat fluctuation range of normal links in a large amount of historical operation data, for example, taking the 95th percentile of normal samples.

[0054] For round-trip delay jitter, the module collects the round-trip delay value of each data packet transmission, forms a delay sequence within the time window, and extracts its jitter amplitude. The jitter amplitude is the mean of the absolute value sequence of adjacent delay differences. The jitter amplitude is used as the feature value of this indicator. The delay jitter amplitude is used to quantify the stability of the link. Its normal range is obtained by fitting test data under different network load environments in the laboratory.

[0055] Regarding packet loss rate, the module calculates the percentage of packet loss per minute, forms a packet loss rate sequence within a time window, and extracts its mean and maximum value. The maximum value is used to capture sudden severe packet loss events, while the mean value reflects the overall transmission reliability. The statistical characteristic value of the packet loss rate index can be used to determine whether the link is in an available edge state.

[0056] In this invention, through the extraction of the above-mentioned multi-dimensional statistical features, the link status monitoring module can characterize the link quality from multiple dimensions such as mean level, fluctuation amplitude, and extreme events. Compared with the method of using only instantaneous values ​​or a single mean, it can identify the link degradation trend earlier and distinguish instantaneous interference from continuous deterioration more accurately. This provides refined link status input for the distribution and diversion module, making the triggering time of the transmission optimization strategy and the autonomous distribution strategy highly consistent with the actual link condition.

[0057] Specifically, the link status monitoring module classifies the health status types published on the information board based on the health status characterization parameter group. The published health status types include three categories: normal status, sub-healthy status, and disconnected status. The health status characterization parameter group includes the heartbeat loss count feature value, round-trip delay jitter feature value, and packet loss rate feature value.

[0058] The link status monitoring module has a pre-set threshold system for various states. The normal threshold range corresponding to the characteristic values ​​of each indicator is used to define the indicator range in which the link is in a stable and usable state. In a simulated environment, an information board and centralized publishing platform are deployed to establish an interference-free and unobstructed 4G / 5G link. A large number of heartbeat data packets are continuously collected. For the normal threshold of the heartbeat loss count characteristic value, the heartbeat loss count is continuously collected every minute, forming a large number of five-minute time window samples. For each sample, the ratio of the average deviation to the average value is calculated, and the distribution of this ratio across all samples is statistically analyzed. The 95th percentile is taken as the upper limit of the normal threshold. For example, in a calibration test, 500 five-minute time window samples are collected. If this ratio does not exceed 0.15 in 95% of the samples, then the upper limit of the normal threshold is set to 0.15, meaning that a heartbeat is considered stable when the average deviation does not exceed 15% of the average value. If the ratio exceeds 0.15, it reflects that the fluctuation of heartbeat loss exceeds the normal range, and there may be intermittent link interruptions or congestion.

[0059] For the characteristic value of round-trip delay jitter, the absolute value of the delay difference of a large number of normally transmitted data packets is collected in the same simulated environment, and the statistical distribution of its mean is calculated. The 90th percentile is taken as the upper limit of the normal threshold, for example, calibrated to 35 milliseconds. That is, when the jitter amplitude exceeds 35 milliseconds, it is considered as abnormal delay fluctuation.

[0060] For the packet loss rate feature value, the module focuses on both the mean and the maximum value. The mean packet loss rate reflects the overall transmission reliability, and its normal upper limit is obtained by taking the 95th percentile of the average packet loss rate during normal transmission, for example, it is calibrated to 1.2%. The maximum packet loss rate is used to capture sudden severe packet loss events, and its normal upper limit is obtained by analyzing the rare instantaneous high packet loss samples in normal transmission, taking the 90th percentile, for example, it is calibrated to 3.5%.

[0061] The link failure threshold is used to define the critical point at which a link can no longer maintain basic communication. This threshold is calibrated using field measurement data. Multiple typical locations along the highway were selected for testing, including tunnel entrances and exits, the middle sections of large bridges, mountain curves, and areas around service areas where wireless signals are easily attenuated or interfered with. For the link failure threshold based on the heartbeat loss frequency characteristic value, artificial communication interruption scenarios were created at these locations, and the continuous change in the heartbeat loss frequency characteristic value was recorded from the onset of link degradation to complete failure. Within the last complete time window before complete link failure, this ratio often increases sharply. The average of this critical value from multiple tests is taken as the link failure threshold, for example, calibrated to 1.2. When the average deviation reaches 1.2 times the average value, it indicates that the fluctuation of heartbeat loss is extremely abnormal, and the link is close to substantial failure. The threshold for continuous heartbeat loss is determined by statistically analyzing the cumulative time from the first heartbeat loss to the protocol stack determining a connection timeout. Based on the default reconnection timeout setting of the wireless communication module and the average recovery time of multiple network disconnection and reconnection tests in the field, it is set to 60 seconds. That is, if no heartbeat response is received within 60 consecutive seconds, regardless of the ratio, the connection is determined to be lost.

[0062] The link break threshold of the packet loss rate characteristic value is determined by monitoring the sudden increase in packet loss rate in the last minute before the link break: the higher of the mean and the maximum value is taken as the judgment criterion. When the mean packet loss rate exceeds 8% or the maximum value exceeds 15%, it is determined that the link break threshold of the packet loss rate has been reached. This value is based on the statistical results of multiple link break tests in which communication was substantially interrupted after the packet loss rate exceeded the critical point.

[0063] In implementation, the link status monitoring module first compares the characteristic values ​​of each indicator with the normal threshold range. Taking a certain intelligence board as an example, if its heartbeat loss count characteristic value is 0.13, round-trip delay jitter characteristic value is 28 milliseconds, average packet loss rate is 0.8%, and maximum packet loss rate is 2.5%, then all three fall within their respective normal threshold ranges, and the intelligence board's publishing health status is determined to be normal, indicating that its link quality fully meets the transmission requirements for real-time, full-volume intelligence publishing.

[0064] If the heartbeat loss count characteristic value of another information board is 0.35, but does not reach the link failure threshold of 1.2, and the duration of continuous heartbeat loss does not exceed 60 seconds, and the round-trip time jitter and packet loss rate are within the normal range, then it is judged as a sub-healthy state, indicating that the heartbeat stability has decreased but the link has not yet completely deteriorated. For example, if the heartbeat loss count characteristic value of an information board suddenly rises to 1.3, it is directly judged as a link failure state; or if there is no heartbeat response for 90 consecutive seconds, it is also judged as a link failure state.

[0065] In this invention, the link status monitoring module associates the determined health status type with the corresponding information board identifier and pushes it to the publishing distribution module in real time. Through a multi-level threshold division mechanism, the continuously changing wireless link quality is discretized into three status categories with clear behavioral orientations: normal status guides full and immediate publishing to ensure information timeliness; sub-healthy status guides transmission optimization strategies, prioritizing the reachability of core information under limited link resources; and disconnected status guides autonomous publishing strategies, enabling the information board to maintain basic service capabilities based on local caching even when it is out of platform control. This mechanism allows the system to adaptively adjust its publishing behavior according to the actual link quality gradient, avoiding frequent strategy switching due to instantaneous fluctuations and preventing resource waste caused by attempting full transmission when the link is severely degraded.

[0066] Specifically, the publishing and distribution module receives event information and corresponding influence distance and direction relationship determination results from the event detection module in real time. These determination results include the influence distance value of each information board relative to the current event and its direction relationship identifier. Simultaneously, the publishing and distribution module obtains the specific values ​​of the upstream and downstream influence lengths corresponding to this event type from the event detection module.

[0067] In implementation, for any information board, the distribution module first extracts the directional relationship identifier of the information board and selects the corresponding influence length for comparison based on the directional relationship: if the directional relationship identifier is upstream, the upstream influence length is used as the comparison benchmark; if the directional relationship identifier is downstream, the downstream influence length is used as the comparison benchmark. Subsequently, the distribution module compares the influence distance value of the information board with the selected influence length value. If the influence distance is less than or equal to the influence length, the information board is determined to be qualified to publish the current event; if the influence distance is greater than the influence length, the information board is determined not to be qualified to publish, and the event is not sent to the information board.

[0068] Let's take a typical event in a highway scenario as an example. Suppose a two-vehicle rear-end collision occurs at kilometer marker K100 on a highway. The event detection module determines the upstream impact length to be 2.0 kilometers and the downstream impact length to be 0.5 kilometers based on the accident type. The information boards located upstream of the accident point include those at K99, K98+500, and K97, with impact distances of 1.0 kilometer, 1.5 kilometers, and 3.0 kilometers respectively. The information boards located downstream of the accident point include those at K100+200 and K100+800, with impact distances of 0.2 kilometers and 0.8 kilometers respectively. The message distribution module makes the following judgments: the information board at K99 has an impact distance of 1.0 km, which is less than the upstream impact length of 2.0 km, so it is deemed qualified to publish; the information board at K98+500 has an impact distance of 1.5 km, which is also less than 2.0 km, so it is deemed qualified to publish; the information board at K97 has an impact distance of 3.0 km, which is greater than 2.0 km, so it is deemed not qualified to publish; the information board at K100+200 has an impact distance of 0.2 km, which is less than the downstream impact length of 0.5 km, so it is deemed qualified to publish; the information board at K100+800 has an impact distance of 0.8 km, which is greater than 0.5 km, so it is deemed not qualified to publish.

[0069] In this invention, by directly comparing the impact distance and the impact length, the asymmetric impact range obtained by the event detection module through spatiotemporal consistency modeling is transformed into a clear and executable release judgment logic. This enables the release behavior of the information board to be precisely matched with the actual propagation law of the event in the road network topology direction. The upstream information board releases in advance within the effective warning distance, the downstream information board releases continuously within the event's occupied range, and the information board beyond the impact length does not participate in the release. This avoids invalid information coverage and driver information overload caused by unified release on long road sections.

[0070] Specifically, after receiving the list of qualified information boards and their corresponding health status types from the event detection module, the distribution module executes differentiated distribution strategies based on the health status type of each information board. It is understandable that in a wireless network environment, link quality changes dynamically, and a single, fixed distribution method cannot simultaneously meet the requirements of real-time performance, reliability, and resource efficiency. By dividing link status into three levels—normal, sub-healthy, and disconnected—and matching them with corresponding distribution behaviors, the system can maximize information timeliness when the link is good, prioritize the accessibility of core information when the link deteriorates, and maintain basic service capabilities even when the link is interrupted, thereby achieving adaptive optimization of information distribution across all scenarios.

[0071] For information boards displaying a "normal" health status, the distribution module employs a full, real-time publishing strategy. At this time, with stable link quality and sufficient bandwidth, the module directly pushes the original event content provided by the event detection module—including complete text and image information such as event type, location, severity, and suggested detour routes—to the information board. Reliable transmission is achieved using a standard TCP / IP protocol stack, ensuring the information is presented to drivers with the highest timeliness and completeness. This strategy aims to fully utilize high-quality link resources, enabling traffic information to be transmitted to passing vehicles immediately and without attenuation.

[0072] For information boards displaying a sub-healthy health status, a transmission optimization strategy is initiated. This strategy reduces transmission load and improves reliability in three ways: First, it reduces the posting frequency. The posting offloading module switches from real-time push mode to low-frequency periodic push, with the preset value for the low-frequency period determined by analyzing historical link jitter data. For example, multiple typical locations are selected along highways, and the link RTT jitter and packet loss rate variation curves are continuously collected for one week. The average interval between two adjacent link quality deterioration troughs is calculated, and 50% of this interval is used as the baseline value for the low-frequency period. This avoids excessively frequent pushes that would burden the link while ensuring that critical information is not delayed for too long; the initial value is 30 seconds.

[0073] Second, content degradation. The module converts the event information to be published from a complete text and image description into a preset short text template or icon format. The short text template only retains the event type, location, and brief suggestion, while the icon format uses predefined symbols, such as accident icons and construction icons. Both are further reduced in data size through compression algorithms. The purpose of content degradation is to prioritize the transmission of core semantics under limited bandwidth resources, avoiding transmission timeouts or packet loss caused by large images or long text.

[0074] Third, protocol stack optimization. The distribution and routing module selects the protocol stack with the lowest data load for transmission based on the real-time status of the current link. For example, when RTT jitter is large but packet loss rate is acceptable, the UDP-based CoAP protocol is preferred over HTTP because CoAP has lower header overhead and supports retransmission; if the packet loss rate is high, lightweight protocols such as MQTT-SN suitable for low-bandwidth environments are used. The selection of the protocol stack is determined through laboratory simulations comparing the success rate and load of each protocol under different link deterioration scenarios, and the optimal protocol for each scenario is pre-configured into the module.

[0075] In addition, the transmission optimization strategy includes a redundancy retransmission mechanism. The module continuously monitors the low point of link jitter, i.e., the period when the round-trip delay jitter value is lower than the normal threshold. During this period, critical information that was not acknowledged in the previous cycle is retransmitted once or multiple times. The number of redundancy retransmissions is calibrated through field tests. Information is simulated and transmitted on typical sub-healthy road sections, and the success rate after a single retransmission is counted. The minimum number of retransmissions required to achieve a cumulative success rate of over 95% is taken as the preset value, for example, 2 times. This mechanism balances bandwidth usage and transmission reliability, avoiding network congestion caused by excessive retransmissions when the link deteriorates.

[0076] For information boards displaying a "disconnected" health status, the distribution module stops sending any new information to that information board and switches to autonomous distribution mode. In this mode, the information board itself becomes the disseminator: it reads the last trusted event information cached in its local memory—the last successfully received valid event before the disconnection—and uses a time decay algorithm to generate and display a safety alert. The time decay algorithm causes the display intensity or content of the alert to gradually fade as the disconnection duration increases, until it disappears completely. The decay curve of the algorithm is calibrated through real-vehicle tests: under multiple disconnection scenarios, the driver's acceptance of the gradually weakening information is observed, and the critical decay rate at which most drivers can still notice the information without being misled is taken as the algorithm parameter. For example, the alert brightness is set to decrease by 10% every 30 seconds; when the brightness drops below 30% of the initial value, the information is automatically hidden.

[0077] Simultaneously, the information board initiates automatic link recovery detection, periodically attempting to re-establish connection with the centralized publishing platform. The detection cycle is determined based on the reconnection timeout setting of the wireless module and the average time taken during multiple network outage recovery tests in the field, generally set to once every 10 seconds. Once the link is restored, the information board immediately synchronizes data with neighboring information boards or roadside edge nodes, broadcasts its last display version number to its neighbors, receives event information missing during the link outage period pushed by its neighbors, and ensures the accuracy of the published content after recovery through consistency checks. After data synchronization is complete, the information board accepts platform scheduling again and exits autonomous mode.

[0078] This invention achieves gradient adaptation to changes in wireless link quality through the above three-layer progressive release strategy: ensuring real-time performance in normal state, optimizing resource utilization and improving reliability in sub-healthy state, and maintaining basic services and ensuring seamless connection after recovery in disconnected state. Thus, in the complex and ever-changing 4G network environment, it always provides accurate, timely and continuous road condition information services to highway travelers.

[0079] Specifically, the feedback module collects display receipt information returned by each information board at a fixed hourly cycle. It then calculates the success rate (ratio of successful submissions to total submissions), average submission latency, and number of submission failures for each information board within a preset time period. These statistics are arranged chronologically to generate a submission performance curve with time on the horizontal axis and success rate on the vertical axis. Typically, the preset time period is 24 hours. To assess whether the submission performance deviates from expectations, the feedback module has a pre-set baseline performance curve. This baseline curve is obtained by collecting historical submission success rates during the system's stable operation period and applying a moving average, reflecting the typical variation pattern of submission performance under normal operating conditions.

[0080] In actual operation, the feedback module compares the current release performance curve with the baseline curve point by point in time, calculating the deviation value at each point in time. This is the current success rate minus the baseline success rate. The deviation threshold is determined by statistically analyzing the standard deviation of the deviation values ​​at each point in time under historical normal operating conditions, taking three times the standard deviation as the threshold to ensure that correction is triggered only when the deviation significantly exceeds the normal fluctuation range. When the absolute value of the deviation at a certain point in time exceeds this threshold, the feedback module generates a correction coefficient: if the current success rate is lower than the baseline value, the correction coefficient is a factor less than 1, normalizing the deviation and mapping it to the 0.8–1.0 range; if it is higher than the baseline value, the correction coefficient is a factor greater than 1, normalizing the deviation and mapping it to the 1.0–1.2 range.

[0081] The feedback module sends the correction coefficient to the event detection module, which then adjusts the upstream and downstream impact lengths of the current event proportionally, thereby achieving a closed-loop adjustment of the release effect on the scope of event impact and dynamically matching the intelligence release scope with actual traffic demand and link performance.

[0082] Specifically, based on the generated deviation value, the feedback module further generates adjustment parameters for the sub-healthy state according to the specific characteristics of the deviation. If the deviation is manifested as a persistently low success rate and increased latency, it indicates that the release strategy under the current sub-healthy state is too aggressive. The feedback module can generate an adjustment to increase the low-frequency cycle value by 1.2 to 1.5 times the original value, for example, increasing the original 30-second cycle to 45 seconds, in order to further reduce the link load.

[0083] If the deviation manifests as a significant fluctuation in the success rate, adjustments can be generated to shorten the cycle or increase the number of redundant resends. The generation of the adjustment content depends on the type of deviation: if the deviation is mainly caused by text transmission failure, the feedback module can generate instructions to compress the length of the short text template or switch to a simpler icon format;

[0084] If the deviation is related to the protocol stack transmission efficiency, a protocol stack switching instruction is generated, such as switching from HTTP to CoAP. The feedback module encapsulates the above adjustment amount and content and sends it to the publishing and distribution module. When the publishing and distribution module subsequently publishes information boards in the sub-healthy state, it adopts the updated low-frequency cycle, template format, and protocol stack, thereby achieving dynamic optimization of the publishing strategy in the sub-healthy state.

[0085] Specifically, the consistency verification module obtains the current display content of adjacent information boards, extracts the display content summary, publication timestamp and self-check parameters of each display content, compares the display content summaries of adjacent information boards bit by bit, compares the publication timestamps by time difference, and compares the self-check parameters by value.

[0086] If the displayed content summary is inconsistent, and / or the time difference of the publication timestamp exceeds the preset time difference threshold, and / or the self-check parameters exceed the preset self-check parameter range, then it is determined that there is an abnormality in the displayed content.

[0087] The consistency verification module acquires the current display content of adjacent information boards at a fixed 30-second interval, extracting a summary of the display content, a publication timestamp, and self-check parameters. These self-check parameters can include temperature, brightness, and status codes reported by the information boards themselves. The module compares the above information from two adjacent information boards: first, it checks if the display content summaries are completely identical; if not, it indicates a substantial difference in the information displayed by the two information boards. Second, it calculates the difference in publication timestamps between the two information boards; if this difference exceeds a preset time difference threshold, it indicates that one information board is lagging in its information update. Finally, it compares whether the values ​​of the self-check parameters are all within the preset range; if they exceed the range, it indicates that the information board may have a hardware failure.

[0088] The preset time difference threshold is calibrated through field tests. Display delays on information boards are simulated in closed test sections or driving simulator environments, artificially creating varying degrees of delay. Drivers' reactions to information discrepancies are observed, and the maximum delay that does not cause confusion is taken as the threshold, for example, 10 seconds. The preset self-test parameter range is determined based on the normal operating range provided in the information board hardware specifications and the statistical distribution of long-term operating data. For example, the temperature range can be -20℃ to 60℃, and the brightness range can be 2000 to 8000 cd / m². If any of the above conditions are met, the module determines that there is an abnormal display content, records the abnormal information board identifier and abnormality type, and triggers subsequent isolation or rollback processing procedures to ensure the consistency of the displayed content of adjacent information boards and avoid misleading drivers due to conflicting information.

[0089] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

[0090] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A centralized highway information dissemination system based on wireless networking, characterized in that, include: The event detection module is used to collect event information from various road segments in the highway network and map the highway network as a mileage axis curve to determine the distance and direction of the impact of events on each information board; the event information includes event type, event location and start time; The link status monitoring module is used to obtain the link status indicators of the information board, and determine the health status characterization parameter group of the information board based on the link status indicators, so as to determine the release health status type of the information board. The distribution module is used to determine whether each information board is qualified to publish an event based on the influence distance and direction relationship. And execute differentiated release strategies according to their release health status type, wherein the release strategies include full-scale instant release strategy, transmission optimization strategy and autonomous release strategy; The feedback module is used to collect feedback information from the information board, generate a release effect curve, and dynamically correct the influence distance and direction relationship in the event detection module based on the deviation between the release effect and the benchmark value, as well as adjust the adjustment content and amount for sub-health status. The consistency verification module is used to verify the consistency of the displayed content of adjacent information boards. The consistency verification includes comparing the display content summary, timestamp and self-check parameters of adjacent information boards to determine whether there is any abnormality in the displayed content.

2. The centralized highway information dissemination system based on wireless networking according to claim 1, characterized in that, The event detection module maps the highway network into a continuous mileage axis curve in mileage order, projects the event location onto the mileage axis curve to obtain the event mapping point, and uses the event mapping point as a reference to determine the upstream and downstream influence lengths along the upstream and downstream directions of the mileage axis curve in combination with the event type. Specifically, for any information board, the influence distance and direction relationship of the information board relative to the event are determined based on the mileage difference between the position of the information board on the mileage axis curve and the event mapping point, as well as the upstream influence length and the downstream influence length.

3. The centralized highway information dissemination system based on wireless networking according to claim 2, characterized in that, The event detection module determines the effective time window of the event based on the start time in the event information, and updates the influence distance and direction relationship based on the effective time window.

4. The centralized highway information dissemination system based on wireless networking according to claim 3, characterized in that, The link status monitoring module acquires the link status indicators of the information board within a preset monitoring time window. The link status indicators include the number of heartbeat loss, round-trip time jitter, and packet loss rate. Statistical feature extraction is performed on each of the link status indicators to obtain the corresponding indicator feature values, and the health status characterization parameter group is integrated and output.

5. The centralized highway information dissemination system based on wireless networking according to claim 4, characterized in that, The link status monitoring module classifies the health status types of the information board based on the health status characterization parameter group. The health status types include three categories: normal status, sub-healthy status, and disconnected status. The health status characterization parameter set includes heart rate loss feature value, round-trip time jitter feature value, and packet loss rate feature value. If all indicator values ​​meet the normal threshold range, the state is judged as normal; if at least one indicator value exceeds the normal threshold range but does not meet the chain break judgment condition, the state is judged as sub-healthy; if the heartbeat loss count characteristic value reaches the chain break threshold, and / or the continuous heartbeat loss duration exceeds the chain break duration threshold, and / or the packet loss rate characteristic value reaches the chain break threshold, the state is judged as chain break.

6. The centralized highway information dissemination system based on wireless networking according to claim 5, characterized in that, The publishing and distribution module is configured to: for any intelligence board, obtain the influence distance and direction relationship of the intelligence board relative to the current event; If the influence distance is less than or equal to the influence length corresponding to the directional relationship, then the information board is deemed qualified to publish the current event.

7. The centralized highway information dissemination system based on wireless networking according to claim 6, characterized in that, The publishing distribution module is also configured to, in response to determining that an intelligence board is qualified to publish, allocate a corresponding publishing strategy according to its publishing health status type. If the published health status type is normal, then the publishing strategy is a full-scale real-time strategy, which publishes the original content of the event information in full and in real time. If the published health status type is sub-healthy, the publishing strategy is to activate the transmission optimization strategy, reduce the publishing frequency to a preset low frequency period, convert the event information to be published into a preset short text template or icon format before sending, and select the protocol stack with the least data load for sending. If the published health status type is "disconnected", then the published strategy is an autonomous published strategy, which stops sending information to the intelligence board, and the intelligence board generates and displays a security prompt message based on the last trusted event in the local cache combined with a time decay algorithm.

8. The centralized highway information dissemination system based on wireless networking according to claim 7, characterized in that, The feedback module calculates the success rate, delay and failure number of each information board within a preset time period based on the receipt information, and generates the release effect curve in the form of a time series. The feedback module compares the release effect curve with the preset baseline curve point by point, calculates the deviation value at each time point, and generates a correction coefficient based on the judgment result that the deviation value exceeds the preset deviation threshold to correct the upstream and downstream impact lengths of the current event.

9. The centralized highway information dissemination system based on wireless networking according to claim 8, characterized in that, The feedback module generates adjustment amounts and adjustment content for the sub-health state based on the deviation, and sends the adjustment amounts and adjustment content to the publishing and distribution module; The adjustment amount includes the increase or decrease of the value of the low-frequency cycle, and the adjustment content includes the adjustment instructions for the text length or icon complexity of the short text template, as well as the switching instructions for the protocol stack.

10. The centralized highway information dissemination system based on wireless networking according to claim 9, characterized in that, The consistency verification module obtains the current display content of adjacent information boards, extracts the display content summary, publication timestamp and self-check parameters of each display content, compares the display content summaries of adjacent information boards bit by bit, compares the publication timestamps by time difference, and compares the self-check parameters by value. If the displayed content summary is inconsistent, and / or the time difference of the publication timestamp exceeds the preset time difference threshold, and / or the self-check parameters exceed the preset self-check parameter range, then it is determined that there is an abnormality in the displayed content.

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