LoRa-based intelligent street lamp low-power-consumption networking communication method and system

Abstract

The invention discloses an intelligent street lamp low-power-consumption networking communication method and system based on LoRa, and relates to the technical field of street lamp low-power-consumption networking communication. The method comprises the following steps: S1, dividing an intelligent street lamp related range in a whole city into a plurality of areas, periodically collecting energy parameters of each channel by a gateway, and uploading the energy parameters; s2, carrying out availability analysis on the channels according to the energy parameters of the channels so as to screen out available channels, and converging the available channels into a new channel index group; s3, receiving a new channel index group, performing time slot optimization according to the new channel index group, and issuing the new channel index group to a gateway so as to return the new channel index group to a street lamp node; s4, the street lamp node analyzes and updates the local channel list after receiving the new channel index group, activates all available channels, and realizes closed loop of dynamic channel configuration; and S5, heartbeat packets are periodically sent to the gateways, and real-time communication state monitoring, health degree evaluation and dynamic strategy adjustment are carried out on the gateways of the whole network.

Description

Technical Field

[0001] The present application relates to the field of low-power networking communication technology for street lamps, and more specifically, to a method and system for low-power networking communication for smart street lamps based on LoRa. Background Art

[0002] Smart streetlight networking communication refers to the interconnection of terminal devices such as single-lamp controllers, various sensors, and actuators through a variety of wired and wireless communication technologies. This allows for remote centralized control, status monitoring, and data collection of streetlights, providing fundamental support for smart city management and value-added services. It is primarily used for centralized streetlight switching, stepless dimming, fault self-diagnosis, energy consumption statistics, environmental and video data transmission, and the delivery of comprehensive services such as public information release, 5G small base stations, Wi-Fi hotspots, and charging stations.

[0003] Current smart streetlight networking communications typically use Semtech's low-power, wide-area wireless communication technology (LoRa, short for Long Range). Because LoRa operates in unlicensed frequency bands, densely populated or improperly configured nodes can cause co-frequency interference, resulting in message collisions, packet loss, and decreased link quality, impacting network capacity and reliability.

[0004] In order to solve the above defects, a low-power networking communication method for smart street lamps based on LoRa is provided. Summary of the Invention

[0005] According to one aspect of the present application, a low-power networking communication method for smart street lamps based on LoRa is provided, the method comprising the following steps:

[0006] The smart streetlights in the entire city are divided into several areas. Each area is equipped with a gateway. Each smart streetlight is a streetlight node. Each streetlight node transmits data to the gateway through a channel. The gateway is responsible for uploading centralized data in its area and issuing return instructions. Each channel within the communication range is numbered, and the gateway periodically collects the energy parameters of each channel and uploads them.

[0007] Perform channel availability analysis based on the energy parameters of each channel to screen out available channels, extract the indexes of the available channels, aggregate them into a new channel index group, and transmit it downlink back to the gateway;

[0008] Receive the new channel index group and optimize the time slot accordingly. Calculate the transmission time slot for each street light node through a centralized or distributed algorithm and send it to the gateway for transmission back to the street light node.

[0009] After receiving a new channel index group, the streetlight node parses and updates the local channel list, activating all available channels to implement a closed-loop dynamic channel configuration. The streetlight node activates the RF module for uplink only during the allocated time slot and enters deep sleep at other times. After execution, the streetlight node includes confirmation and energy parameters in the next uplink window to drive the next round of scheduling, forming a closed-loop optimization.

[0010] Periodically send heartbeat packets to the gateway to perform real-time communication status monitoring, health assessment, and dynamic policy adjustment for gateways across the entire network.

[0011] Optionally, the specific execution process of the availability analysis to filter out available channels is as follows:

[0012] Extract the energy parameters of each channel, including RSSI, SNR, PER, and Dcle. Normalize the RSSI, SNR, PER, and Dcle of each channel. The specific normalization formula is: RSSI max 、RSSI min They are the maximum RSSI value and the minimum RSSI value under ideal channel conditions. The system defaults to RSSI max =0dB, RSSI min =-120dB, which can be manually changed by our technicians according to actual conditions; SNR max , SNR min They are the maximum and minimum SNR values under ideal channel conditions. The default SNR of this system is max =10dB, SNR min =-20dB, which can be manually changed by our technicians according to actual conditions;

[0013] Then, the normalized RSSI, SNR, PER and Dcle are weighted and fused to obtain the channel quality index at a certain moment of the channel; the channel quality index at each moment in the monitoring period is averaged and the variance is calculated to obtain the channel index quality average value and channel quality discrete value, which are marked as δ 信道 and s 2 信道 ; When the channel satisfies both , it is marked as an available channel.

[0014] Optionally, the execution process of time slot optimization is:

[0015] S3-1, initialization:

[0016] Extract time slot period T cycle , and divide it into P time slots, each time slot length is Δt;

[0017] The δ of each channel in the available channel index group is 信道 and s 2 信道 By formula Calculate the available index of each available channel, and sort the channels in the available channel index group in descending order according to their corresponding available indexes;

[0018] S3-2, model construction:

[0019] Make a binary decision variable: x i,t ∈{0,1}, where i is any streetlight node, t represents any time slot; 1 represents allocation, 0 represents unallocated;

[0020] Formulate the disturbance variable y i,j,t ∈{0,1}, which indicates whether nodes i and j have co-frequency interference in time slot t, 1 indicates interference, 0 indicates no interference; j≠i, j represents any street light node except i;

[0021] Formulate the objective function to minimize total interference and energy consumption: where c int erference is the interference penalty coefficient, P i is the communication power consumption of streetlight node i;

[0022] S3-3, large-scale scenario solution strategy:

[0023] Relax the binary variable to a continuous variable: x i,t ∈[0,1] and y i,j,t ∈[0,1], solve the relaxed linear programming problem and quickly obtain an approximate solution;

[0024] Round off the variables close to 1 in the relaxed solution. If x i,t ≥θ, then fix x i,t =1, the remaining unfixed variables are allocated by greedy algorithm, with x being the first choice i,t Time slots with larger values;

[0025] S3-4, conflict repair and local search:

[0026] Conflict detection is performed on the constraints that may be violated after rounding to determine whether the time slot capacity constraints and interference variables are met. Excess street light nodes are randomly removed, and nodes in the conflicting time slots are reallocated to adjacent time slots.

[0027] Use simulated annealing or tabu search to iteratively optimize the objective function in the neighborhood solution space, exchange the time slot allocation of two nodes, and accept the inferior solution with a certain probability to avoid falling into the local optimum; thus, the time slot allocation table can be output;

[0028] S3-5, the new channel index group and time slot allocation table are packaged and sent to the gateway, which then transmits them back to each streetlight node.

[0029] Optionally, the constraints of the objective function are:

[0030] 4-1, Time slot capacity limitation: Each time slot can be allocated up to N max Each streetlight node to avoid overload;

[0031] 4-2, Node requirement constraints: If two streetlight nodes are activated in the same time slot, it is marked as interference;

[0032] 4-3, Duty cycle limitation: The total activation time slot of street light node i shall not exceed the maximum duty ratio limit T max .

[0033] Optionally, a heartbeat packet is sent to the gateway to monitor the gateway communication status:

[0034] Periodically send heartbeat packets to each gateway and record the heartbeat packet sending time. Detect the online status and response time of the gateway online, record the receiving time, and calculate the time difference between the receiving time and its corresponding sending time to get the response duration. If no response to the heartbeat packet is received from the gateway, the gateway will be marked as an offline gateway. When the response duration is within the default preset duration of this system, it indicates that the gateway is in a normal online state, and the gateway will be marked as an online gateway. Otherwise, the gateway will be marked as a response abnormal gateway.

[0035] Optionally, the gateway's health assessment is:

[0036] Obtain the memory, packet loss rate, restart times, latency, and temperature of each online gateway during the monitoring period. For each indicator x, use min-max linear normalization. The specific processing formula is: Among them L crit 、L warm are the key threshold and warning threshold of each indicator; L crit When this value is reached or exceeded, the indicator is considered "serious" or "faulty", and the normalized result is 1; L warm Indicates that starting from this value, the indicator enters the "warning" range, and the normalized mapping begins to produce values greater than zero; the default indicator of this system - L of memory crit =90%, L warm =80%; the default indicator of this system - packet loss rate L crit =5%, L warm =1%; the default indicator of this system - the number of restarts L crit =3,Lwarm =1; the default indicator of this system - delayed L crit =500ms, L warm =100ms; the default indicator of this system is L of temperature crit =85℃, L warm =70℃;

[0037] The normalized indicators are weighted and fused to obtain the health score at a certain moment in the monitoring period, and the mean and variance are calculated to obtain the average score and discrete value of the health score, which are marked as δ 网关 and s 2 网关 ;

[0038] When the channel satisfies When the online gateway is recorded as a trusted gateway, the trusted gateway group is refined and each trusted gateway is activated.

[0039] Optionally, count the number of trusted gateways. If the number of trusted gateways is less than the default gateway standard number of this system, start the street light node communication optimization strategy; the dynamic strategy of the gateway is adjusted as follows:

[0040] Obtain the pedestrian flow, vehicle flow, and flow demand of each area during the monitoring period, normalize them, and then perform weighted fusion calculation to obtain the node key value of the area; thus, the node key value at each moment in the monitoring period can be obtained, and the mean value is calculated to obtain the key mean value, with key threshold 1 (this system defaults to 0.4) and key threshold 2 (this system defaults to 0.7);

[0041] If the critical mean value ≥ critical threshold 2, the area is recorded as a critical area;

[0042] If key threshold 1 < key threshold < key threshold 2, the area is recorded as a secondary area;

[0043] If the key mean ≤ the key threshold, the area is marked as a low-level area, and the reporting frequency of each streetlight node in the low-level area is downgraded.

[0044] According to one aspect of the present application, a LoRa-based low-power networking communication system for smart street lamps is provided. The system includes: a server, a gateway, and a street lamp node; the server has a built-in channel monitoring unit, a time slot scheduling unit, and a gateway monitoring unit; the street lamp node has a built-in LoRa wireless module, which transmits data to the gateway through a channel by performing single-hop uplink and downlink communication on a configured unlicensed frequency band channel. The gateway is responsible for uploading centralized data in its area to the server and issuing instructions transmitted back by the server;

[0045] The channel monitoring unit performs channel availability analysis based on the energy parameters of each channel to screen out available channels, extracts the indexes of the available channels, aggregates them into a new channel index group, and transmits it downlink back to the gateway;

[0046] The time slot scheduling unit receives a new channel index group and optimizes the time slot accordingly. It calculates the sending time slot for each street light node through a centralized or distributed algorithm and sends it to the gateway for transmission back to the street light node.

[0047] The gateway monitoring unit is used to perform real-time communication status monitoring, health assessment and dynamic strategy adjustment on gateways across the entire network.

[0048] Compared with the prior art, the present invention has the following beneficial effects:

[0049] (1) This application divides the city into several small areas and deploys gateways in each area to avoid overload in "hot spots" or blind spots in "dead corners", ensuring that each street light node is covered by at least one gateway. M channels are numbered and energy parameters are monitored, so that the server can grasp the interference and load status of each channel in real time. Based on the "trustworthy" judgment of the mean and variance, high-interference or unstable channels can be eliminated, and a high-quality available channel group can be automatically formed to reduce collisions and packet loss.

[0050] (2) This application arranges channels in descending order of available index to ensure that high-quality channels are allocated to high-traffic or key nodes first. The binary decision and interference variable model can clearly characterize the relationship between time slot allocation and frequency conflict, provide complete information for the optimizer, minimize the "interference penalty + energy consumption" goal, take into account network reliability and terminal life cycle, avoid simply pursuing throughput while ignoring energy consumption, conflict repair and meta-heuristic optimization such as simulated annealing / tabu search, and can further reduce the probability of conflict based on the initial solution to avoid the local optimal dilemma; street lamp nodes only activate radio frequency within their own time slots and available channel groups, and sleep deeply at other times to maximize battery life or reduce network source loss; execution confirmation and energy parameters are attached in the next uplink to provide the latest link quality information for the next round of channel and time slot scheduling, forming a continuous optimization closed loop;

[0051] (3) This application monitors the online and response delay of the gateway through heartbeat packets, quickly identifies offline or abnormal response gateways, improves the overall network reliability, normalizes the multi-dimensional indicators of the gateway (memory, packet loss, restart, delay, temperature) and weighted fusion to obtain the health score and variance, which can intuitively reflect the stability and potential risks of the gateway. Based on the number of "trusted gateways" and the health score, node optimization or operation and maintenance warning is triggered to achieve the network's adaptive self-healing capability and reduce the cost of manual intervention; based on the key value classification of nodes according to pedestrian flow, vehicle flow and traffic demand, ensure communication priority in key areas and improve the availability of core urban functions; reduce the reporting frequency for low-level areas, alleviate the sudden load caused by the loss of gateways, and ensure business continuity in key areas and key nodes;

[0052] In summary, the LoRa smart street light network of the present invention can achieve self-perception, self-assessment, and self-optimization, ensuring an organic balance between coverage, capacity, energy efficiency, and reliability in large-scale, high-density, and complex electromagnetic environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of this application. The exemplary embodiments and descriptions of this application are intended to explain this application and do not constitute an improper limitation on this application. In the accompanying drawings:

[0054] Figure 1 A flowchart of the method of the present invention;

[0055] Figure 2 This is a system connection block diagram of the present invention. DETAILED DESCRIPTION

[0056] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0057] In order to enable those skilled in the art to better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of this application.

[0058] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present application described here. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0059] like Figure 1-2 As shown, the embodiment of the present application provides a low-power networking communication method for smart street lamps based on LoRa. The method is implemented based on a low-power networking communication system for smart street lamps based on LoRa, wherein the system includes a street lamp node, a gateway and a server; the server has a built-in channel allocation monitoring unit and a time slot scheduling unit;

[0060] The method comprises the following steps:

[0061] S1: The smart streetlights in the entire city are divided into several areas. Each area is equipped with a relay device - a gateway. Each smart streetlight is a streetlight node. Each streetlight node has a built-in LoRa wireless module. Through single-hop uplink and downlink communication on the configured unlicensed frequency band channel, data is transmitted to the gateway through the channel. The gateway is responsible for uploading the centralized data of the area to the server and issuing the instructions sent back by the server.

[0062] The channels within the communication range are numbered m, where m = 1, 2, 3, ..., M, where M∈ is a positive integer representing the total number of channels and m represents any channel number, i.e., the signal index number. The gateway periodically collects the energy parameters of each channel and sends them to the server.

[0063] S2: After the server receives the energy parameters of each channel, the server's built-in channel monitoring unit performs an availability analysis of the channel based on the received energy parameters. Specifically:

[0064] Extract the energy parameters of each channel. Specific energy parameters include RSSI (a link layer signal strength indicator measured in decibels, typically less than or equal to zero; the closer to zero, the stronger the signal), SNR (signal-to-noise ratio, indicating the difference in strength between the desired signal and the ambient noise), PER (frame error rate, representing the ratio of the number of complete data frames that the receiver failed to correctly decode to the total number of transmitted frames within a certain time period or number of transmission attempts), and Dcle (duty cycle, representing the ratio of the actual signal transmission time per unit time to the total duration of that time period). Normalize the RSSI, SNR, PER, and Dcle values for each channel using the following formula: RSSI max 、RSSI min They are the maximum RSSI value and the minimum RSSI value under ideal channel conditions. The system defaults to RSSI max =0dB, RSSI min =-120dB, which can be manually changed by technicians in this field according to actual conditions; SNR max , SNR min They are the maximum and minimum SNR values under ideal channel conditions. The default SNR of this system is max =10dB, SNR min =-20dB, which can be manually changed by those skilled in the art according to actual conditions; the normalized RSSI, SNR, PER and Dcle are then weighted and fused to obtain the channel quality index at a certain moment of the channel; the channel quality index at each moment in the monitoring period is averaged and the channel quality discrete value is obtained by mean calculation and variance calculation, and they are marked as δ 信道 and s 2 信道 ; When the channel satisfies both When , it indicates that the channel quality is reliable and it is marked as an available channel; and These are the default standard judgment mean and standard judgment variance of this system, which can also be fine-tuned by technical personnel based on actual conditions;

[0065] Extract the index of available channels, aggregate them into a new channel index group, and send it downlink back to the gateway; the network node uses LoRa radio frequency to broadcast the command frame (new channel index group) in the receiving window of the street light node;

[0066] By dividing the city into several small areas and deploying a gateway in each area, we can avoid overload in "hotspot" areas or blind spots in "dead corners", ensuring that each street light node is covered by at least one gateway; by numbering M channels and monitoring energy parameters, the server can grasp the interference and load status of each channel in real time; based on the "trusted" judgment of the mean and variance, high-interference or unstable channels can be eliminated, and a high-quality available channel group can be automatically formed to reduce collisions and packet loss.

[0067] In step S3, the server's built-in time slot scheduling unit receives the new channel index group and optimizes the time slot accordingly. It calculates the transmission time slot for each street light node through a centralized or distributed algorithm and sends it to the gateway for transmission back to the street light node. Specifically:

[0068] S3-1, initialization:

[0069] Extract the default time slot period T of this system cycle (The cycle length of the overall frame is 10 minutes by default in this system, and this value can be manually changed by those skilled in the art), and it is divided into P time slots, each time slot length is Δt (the duration of each time slot);

[0070] The δ of each channel in the available channel index group is 信道 and s 2 信道 By formula Calculate the available index of each available channel, and sort the channels in the available channel index group in descending order according to their corresponding available indexes;

[0071] S3-2, model construction:

[0072] Make a binary decision variable: x i,t ∈{0,1}, where i is any streetlight node, t represents any time slot; 1 represents allocation, 0 represents unallocated;

[0073] Formulate the disturbance variable y i,j,t ∈{0,1}, which indicates whether nodes i and j have co-frequency interference in time slot t, 1 indicates interference, 0 indicates no interference; j≠i, j represents any street light node except i;

[0074] Formulate the objective function to minimize total interference and energy consumption: where c int erference is the default interference penalty coefficient of this system, P i is the communication power consumption of streetlight node i; the constraints of the objective function are: (1) time slot capacity limitation: Each time slot can be allocated up to N max Each streetlight node avoids overload; (2) Node demand constraints: If two streetlight nodes are activated in the same time slot, it is marked as interference; (3) Duty cycle limitation: The total activation time slot of street light node i shall not exceed the maximum duty ratio limit T max ;

[0075] S3-3, large-scale scenario solution strategy:

[0076] Relax the binary variable to a continuous variable: x i,t ∈[0,1] and y i,j,t ∈[0,1], solve the relaxed linear programming problem and quickly obtain an approximate solution;

[0077] Round off the variables close to 1 in the relaxed solution. If x i,t ≥θ (θ is the default threshold of this system, which is 0.8. This value can be manually changed by technicians in this field as needed. For example, in a high-density scenario, technicians will adjust it to 0.9). Then, x is fixed. i,t =1, the remaining unfixed variables are allocated by greedy algorithm, with x being the first choice i,t Time slots with larger values;

[0078] S3-4, conflict repair and local search:

[0079] Conflict detection is performed for constraints that may be violated after rounding (such as time slot limit exceeded, interference not eliminated), to determine whether the time slot capacity constraint is satisfied and whether the interference variables satisfy Randomly remove excess streetlight nodes, or reallocate nodes in conflicting time slots to adjacent time slots based on priority;

[0080] Use simulated annealing (SA) or taboo search (TS) to iteratively optimize the objective function in the neighborhood solution space, swap the time slot allocation of two nodes, or move the time slot position of a single node, and accept inferior solutions with a certain probability set by the system to avoid falling into local optimality; thus, a time slot allocation table can be output;

[0081] S3-5: Pack the new channel index group and time slot allocation table and send them to the gateway, which then transmits them back to each streetlight node.

[0082] S4: After receiving the new channel index group, the streetlight node parses and updates the local channel list, activating all available channels to implement a closed-loop dynamic channel configuration. The streetlight node activates the RF module for uplink only during the allocated time slot and enters deep sleep at other times to reduce power consumption and avoid overlapping with other timeslots. After execution, the streetlight node includes confirmation and energy parameters in the next uplink window to drive the next round of scheduling, forming a closed-loop optimization.

[0083] By arranging channels in descending order of available index, high-quality channels are preferentially allocated to high-traffic or critical nodes. The binary decision and interference variable model can clearly characterize the relationship between time slot allocation and co-frequency conflicts, providing complete information for the optimizer, minimizing the "interference penalty + energy consumption" goal, taking into account network reliability and terminal life cycle, and avoiding the pursuit of throughput while ignoring energy consumption. Conflict repair and meta-heuristic optimization such as simulated annealing / tabu search can further reduce the probability of conflicts based on the initial solution and avoid the local optimal dilemma. Street light nodes only activate the radio frequency within their own time slots and available channel groups, and are in deep sleep at other times to maximize battery life or reduce network source loss. In the next uplink, execution confirmation and energy parameters are included to provide the latest link quality information for the next round of channel and time slot scheduling, forming a continuous optimization closed loop.

[0084] S5: The server has a built-in gateway monitoring unit, which is responsible for real-time communication status monitoring, health assessment, and dynamic policy adjustment of all gateways in the network. Specifically:

[0085] Periodically send heartbeat packets to each gateway and record the time when the heartbeat packets are sent. Detect the online status and response time of the gateway online, then record the receiving time and calculate the time difference between the receiving time and the corresponding sending time to get the response time. If no response is received from the gateway for the heartbeat packet, the gateway will be marked as an offline gateway. When the response time is within the preset time of the system, it means that the gateway is in a normal online state, and the gateway will be marked as an online gateway. Otherwise, the gateway will be marked as a response abnormal gateway.

[0086] Obtain the memory, packet loss rate, restart times, latency, and temperature of each online gateway during the monitoring period. For each indicator x (where x represents any one of memory, packet loss rate, restart times, latency, and temperature), use min-max linear normalization. The specific processing formula is: Among them L crit 、L warm are the key threshold and warning threshold of each indicator; L crit When this value is reached or exceeded, the indicator is considered "serious" or "faulty", and the normalized result is 1; L warm Indicates that starting from this value, the indicator enters the "warning" range, and the normalized mapping begins to produce values greater than zero; the default indicator of this system - L of memory crit =90%, L warm =80%; the default indicator of this system - packet loss rate L crit =5%, L warm =1%; the default indicator of this system - the number of restarts L crit =3,L warm =1; the default indicator of this system - delayed L crit =500ms, Lwarm =100ms; the default indicator of this system is L of temperature crit =85℃, L warm =70℃;

[0087] The normalized indicators are weighted and fused to obtain the health score at a certain moment in the monitoring period, and the mean and variance are calculated to obtain the average score and discrete value of the health score, which are marked as δ 网关 and s 2 网关 ; When the channel satisfies both When , it indicates that the gateway status is trustworthy, then the online gateway is recorded as a trusted gateway, and the trusted gateway group is updated accordingly, and each trusted gateway is activated;

[0088] Count the number of trusted gateways. If the number of trusted gateways is less than the default gateway standard number of this system, it means that the number of gateways is insufficient to meet the information communication requirements of all street light nodes. In this case, the street light node communication optimization strategy is activated to ensure the uplink of key data and the downlink of instructions. The specific street light node communication optimization strategy is as follows:

[0089] Obtain the pedestrian flow, vehicle flow and flow demand of each area within the monitoring period (representing the sum of the uplink data packets of each street light node in the area), normalize them, and then perform weighted fusion calculation to obtain the node key value of the area (the greater the pedestrian flow and vehicle flow in the area, the greater the popularity of the area, and the larger the node key value; the larger the uplink data packet of the street light node, the greater the flow demand of the area, the larger the node key value); thus, the node key value of each moment in the monitoring period can be obtained, and the mean is calculated to obtain the key mean, with a key threshold 1 (this system sets it to 0.4 by default) and a key threshold 2 (this system sets it to 0.7 by default); if the key mean ≥ key threshold 2, the area is recorded as a key area; if the key threshold 1 < key mean < key threshold 2, the area is recorded as a secondary area; if the key mean ≤ key threshold 1, the area is recorded as a low-level area, and the reporting frequency of each street light node in the low-level area is downgraded;

[0090] By monitoring the online status and response delay of gateways through heartbeat packets, offline or abnormally responding gateways can be quickly identified to improve overall network reliability. The health score and variance of the gateway's multi-dimensional indicators (memory, packet loss, restart, delay, temperature) are normalized and weighted and integrated to intuitively reflect the stability and potential risks of the gateway. Based on the number of "trusted gateways" and the health score, node optimization or operation and maintenance warnings are triggered to achieve the network's adaptive self-healing capabilities and reduce the cost of manual intervention. Nodes are classified according to key values based on pedestrian, vehicle and traffic demand to ensure communication priority in key areas and improve the availability of core urban functions. The reporting frequency is reduced for low-level areas to alleviate sudden loads caused by gateway loss and ensure business continuity in key areas and key nodes.

[0091] It should also be noted that the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, commodity, or apparatus that includes a series of elements includes not only those elements but also other elements not explicitly listed, or includes elements inherent to such process, method, commodity, or apparatus. In the absence of further limitations, an element defined by the phrase "comprises a ..." does not exclude the presence of other identical elements in the process, method, commodity, or apparatus that includes the element.

[0092] The above are merely embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application should all be included within the scope of the claims of the present application.

Claims

1. A low-power network communication method for smart street lights based on LoRa, comprising: The smart streetlights in the entire city are divided into several areas. Each area is equipped with a gateway. Each smart streetlight is a streetlight node. Each streetlight node transmits data to the gateway through a channel. The gateway is responsible for uploading centralized data in its area and issuing return instructions. Each channel within the communication range is numbered, and the gateway periodically collects the energy parameters of each channel and uploads them. It is characterized by further comprising: Perform channel availability analysis based on the energy parameters of each channel to screen out available channels, extract the indexes of the available channels, aggregate them into a new channel index group, and transmit it downlink back to the gateway; Receive the new channel index group and optimize the time slot accordingly. Calculate the transmission time slot for each street light node through a centralized or distributed algorithm and send it to the gateway for transmission back to the street light node. After receiving a new channel index group, the streetlight node parses and updates the local channel list, activating all available channels to implement a closed-loop dynamic channel configuration. The streetlight node activates the RF module for uplink only during the allocated time slot and enters deep sleep at other times. After execution, the streetlight node includes confirmation and energy parameters in the next uplink window to drive the next round of scheduling, forming a closed-loop optimization. Periodically send heartbeat packets to the gateway to perform real-time communication status monitoring, health assessment, and dynamic policy adjustment for gateways across the entire network.

2. The low-power network communication method for smart street lamps based on LoRa according to claim 1, characterized in that: The specific execution process of availability analysis to screen out available channels is as follows: Extract the energy parameters of each channel, including RSSI, SNR, PER, and Dcle; normalize the RSSI, SNR, PER, and Dcle of each channel, and then perform weighted fusion calculation on the normalized RSSI, SNR, PER, and Dcle to obtain the channel quality index at a certain moment of the channel; calculate the mean and variance of the channel quality index at each moment in the monitoring period to obtain the channel index quality average and channel quality discrete value, respectively, and mark them as δ 信道 and When the channel satisfies , it is marked as an available channel.

3. The low-power network communication method for smart street lamps based on LoRa according to claim 2, characterized in that: The execution process of time slot optimization is as follows: S3-1, initialization: Extract time slot period T cycle , and divide it into P time slots, each time slot length is Δt; The δ of each channel in the available channel index group is 信道 and s 2 信道 By formula Calculate the available index of each available channel, and sort the channels in the available channel index group in descending order according to their corresponding available indexes; S3-2, model construction: Make a binary decision variable: x i,t ∈{0,1}, where i is any streetlight node, t represents any time slot; 1 represents allocation, 0 represents unallocated; Formulate the disturbance variable y i,j,t ∈{0,1}, which indicates whether nodes i and j have co-frequency interference in time slot t, 1 indicates interference, 0 indicates no interference; j≠i, j represents any street light node except i; Formulate the objective function to minimize total interference and energy consumption: where c interference is the interference penalty coefficient, P i is the communication power consumption of streetlight node i; S3-3, large-scale scenario solution strategy: Relax the binary variable to a continuous variable: x i,t ∈[0,1] and y i,j,t ∈[0,1], solve the relaxed linear programming problem and quickly obtain an approximate solution; Round off the variables close to 1 in the relaxed solution. If x i,t ≥θ, then fix x i,t =1, the remaining unfixed variables are allocated by greedy algorithm, with x being the first choice i,t Time slots with larger values; S3-4, conflict repair and local search: Conflict detection is performed on the constraints that may be violated after rounding to determine whether the time slot capacity constraints and interference variables are met. Excess street light nodes are randomly removed and nodes in the conflicting time slots are reallocated to adjacent time slots. Use simulated annealing or tabu search to iteratively optimize the objective function in the neighborhood solution space, exchange the time slot allocation of two nodes, and accept the inferior solution with a certain probability to avoid falling into the local optimum; thus, the time slot allocation table can be output; S3-5, the new channel index group and time slot allocation table are packaged and sent to the gateway, which then transmits them back to each streetlight node.

4. The low-power network communication method for smart street lamps based on LoRa according to claim 3, characterized in that: The constraints of the objective function are: 4-1, Time slot capacity limitation: Each time slot can be allocated up to N max Each streetlight node should avoid overload; 4-2, Node requirement constraints: If two streetlight nodes are activated in the same time slot, it is marked as interference; 4-3, Duty cycle limitation: The total activation time slot of street light node i shall not exceed the maximum duty ratio limit T max .

5. The low-power network communication method for smart street lamps based on LoRa according to claim 4, characterized in that: The heartbeat packet is sent to the gateway to monitor the gateway communication status: Periodically send heartbeat packets to each gateway and record the heartbeat packet sending time. Detect the online status and response time of the gateway online, record the receiving time, and calculate the time difference between the receiving time and its corresponding sending time to obtain the response time. If no response is received from the gateway to the heartbeat packet, the gateway will be marked as an offline gateway; when the response time is within the system's default preset time, it means that the gateway is in a normal online state, and the gateway will be marked as an online gateway; Otherwise, the gateway is marked as an abnormal response gateway.

6. The low-power network communication method for smart street lamps based on LoRa according to claim 5, characterized in that: The health assessment of the gateway is: Obtain the memory, packet loss rate, restart times, latency, and temperature of each online gateway during the monitoring period. For each indicator x, use min-max linear normalization processing, perform weighted fusion calculation on the normalized indicators to obtain the health score at a certain moment in the monitoring period, and perform mean and variance calculation on them respectively to obtain the average score and health score discrete value, and mark them as δ 网关 and s 2 网关 ; When the channel satisfies When the online gateway is recorded as a trusted gateway, the trusted gateway group is refined and each trusted gateway is activated.

7. The low-power network communication method for smart street lamps based on LoRa according to claim 6, characterized in that: Count the number of trusted gateways. If the number of trusted gateways is less than the default gateway standard number of this system, start the street light node communication optimization strategy; The dynamic policy of the gateway is adjusted as follows: Obtain the pedestrian flow, vehicle flow and flow demand of each area within the monitoring period, normalize them and then perform weighted fusion calculation to obtain the node key value of the area; thus, the node key value at each moment in the monitoring period can be obtained, and the mean value is calculated to obtain the key mean, and key threshold 1 and key threshold 2 are set; If the critical mean value ≥ critical threshold 2, the area is recorded as a critical area; If key threshold 1 < key threshold < key threshold 2, the area is recorded as a secondary area; If the key mean ≤ the key threshold, the area is marked as a low-level area, and the reporting frequency of each streetlight node in the low-level area is downgraded.

8. A LoRa-based smart street light low-power networking communication system, characterized by A LoRa-based low-power network communication method for smart street lamps according to any one of claims 1 to 7, the system comprising: a server, a gateway, and a street lamp node; the server having a built-in channel monitoring unit, a time slot scheduling unit, and a gateway monitoring unit; the street lamp node having a built-in LoRa wireless module, which transmits data to the gateway through the channel by performing single-hop uplink and downlink communication on a configured unlicensed frequency band channel; the gateway is responsible for uploading centralized data of its area to the server and issuing instructions transmitted back by the server; The channel monitoring unit performs channel availability analysis based on the energy parameters of each channel to screen out available channels, extracts the indexes of the available channels, aggregates them into a new channel index group, and transmits it downlink back to the gateway; The time slot scheduling unit receives a new channel index group and optimizes the time slot accordingly. It calculates the sending time slot for each street light node through a centralized or distributed algorithm and sends it to the gateway for transmission back to the street light node. The gateway monitoring unit is used to perform real-time communication status monitoring, health assessment and dynamic strategy adjustment on gateways across the entire network.

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