Link-level low-power-consumption bidirectional relay method for wireless fire alarm system

Abstract

The invention provides a link-level low-power-consumption two-way relay method for a wireless fire alarm system, relates to the field of fire alarm, and solves the problems of high energy consumption of multi-level relays, large downlink instruction delay and incapability of self-recovery after link out-of-step in the existing wireless fire alarm system. The method comprises the following steps that: the wireless terminal performs initial synchronization with the wireless repeater by using a maximum length preamble; the synchronization state of the wireless terminal and the wireless repeater is kept through preset periodic heartbeat communication, and the first clock accumulative error of the wireless repeater and the second clock accumulative error of the wireless terminal are monitored and calculated in real time. And predicting time data of the wireless repeater for periodically scanning the communication channel next time, and generating a low-power-consumption synchronization strategy. The optimized signal sending window and the shortened lead code length are recognized, and relay forwarding of uplink data or receiving and responding of downlink data are completed. And dynamically maintaining or forcibly reconstructing the synchronization state based on the communication success rate. The application is used in a fire alarm process.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of fire alarm, in particular to a wireless fire alarm system link level low-power bidirectional relay method. BACKGROUND

[0002] With the rapid development of wireless communication technology, wireless fire alarm systems have been widely used in various places. Such systems are usually composed of wireless controllers, gateways, repeaters and terminal detection devices (such as smoke detectors, manual alarm buttons, etc.), and realize the detection, transmission and linkage control of fire signals through wireless means. In the prior art, communication usually uses fixed preamble length and static communication timing for synchronization and data transmission between devices. Although this method is simple to implement, in the initial synchronization stage of actual application, due to unknown clock bias and device heterogeneity, the fixed length preamble may not completely cover the channel scanning period of the repeater, resulting in synchronization failure or the need for multiple attempts, increasing the time and power consumption of initial network entry. At the same time, relying on calibration of a single clock source, it cannot effectively cope with the clock drift accumulation caused by the difference in crystal oscillator accuracy, environmental temperature changes and other factors between the repeater and the terminal device, resulting in a decrease in synchronization accuracy, increasing the delay of uplink alarm and downlink instructions, and reducing communication reliability. SUMMARY

[0003] The present application provides a wireless fire alarm system link level low-power bidirectional relay method, which solves the technical problems of high energy consumption of multi-level relay, large downlink instruction delay and inability to self-recover after link step loss in existing wireless fire alarm systems.

[0004] To achieve the above purpose, the present application adopts the following technical solutions: In a first aspect, a wireless fire alarm system link-level low-power bidirectional relay method includes: a wireless terminal using a maximum length preamble to initially synchronize with a wireless relay, the duration of the maximum length preamble covering a default channel activity detection period of the wireless relay. Based on a time reference source provided by a wireless fire alarm controller, a synchronization state between the wireless terminal and the wireless relay is maintained through a preset periodic heartbeat communication, and a first clock cumulative error of the wireless relay and a second clock cumulative error of the wireless terminal are monitored and calculated in real time. A dynamic synchronization processing model is constructed, and based on the synchronization state, the first clock cumulative error and the second clock cumulative error, time data of the next periodic scanning of the communication channel by the wireless relay is predicted through the dynamic synchronization processing model, and a low-power synchronization strategy is generated. The low-power synchronization strategy includes an optimized signal transmission window and a shortened preamble length. When the wireless terminal needs to send uplink alarm data or issue a downlink control command, the optimized signal transmission window and the shortened preamble length are identified through the low-power synchronization strategy, and when the time arrives at the identified signal transmission window, the corresponding shortened preamble length is sent, and the relay forwarding of the uplink data or the reception and response of the downlink data are completed, wherein the downlink control command processing includes switching to the downlink channel for data transmission. All communication results of the wireless relay are detected in real time, and the synchronization state is dynamically maintained or forcibly reconstructed based on the communication success rate, to ensure the stability of the communication link.

[0005] Based on the above technical solution, in the wireless fire alarm system link-level low-power bidirectional relay method provided in the present application, the maximum length preamble initial synchronization mechanism, the periodic heartbeat communication and the double clock error monitoring, the dynamic synchronization processing model, and the communication result real-time detection and state forced reconstruction mechanism jointly constitute a complete adaptive synchronization system. The maximum length preamble initial synchronization mechanism is used before use to ensure reliable first wake-up under unknown clock deviation, solve the synchronization failure problem caused by insufficient preamble length, and combine the periodic heartbeat communication and the double clock error monitoring based on the high-precision time reference to track the clock drift of the relay and the terminal in real time, overcome the defect that single clock calibration cannot cope with error accumulation of heterogeneous devices, and thus ensure the accuracy of synchronization. The dynamic synchronization processing model predicts the best communication window and generates a low-power strategy of shortened preamble, which can reduce the use of long preamble, thereby reducing high energy consumption and ensuring the reliability of communication. Finally, the communication result real-time detection and state forced reconstruction mechanism forms a closed-loop control, dynamically adjusts the heartbeat period or triggers re-synchronization, effectively avoids the problem of communication interruption caused by automatic recovery due to link quality deterioration, and thus can reduce system power consumption while improving the real-time performance and reliability of bidirectional communication, solving the problems of high energy consumption of multi-level relay, large downlink command delay, and inability to self-recover after link step-out in the wireless fire alarm system.

[0006] In combination with the first aspect, in a possible implementation, the wireless terminal uses a maximum length preamble to perform initial synchronization with the wireless repeater, including: the wireless terminal sends a wake-up frame with a maximum length preamble to the wireless repeater, the duration of the maximum length preamble is not less than 2000 milliseconds. After the wireless repeater detects the maximum length preamble by scanning the channel, the wireless repeater returns a response signal to the wireless terminal, the response signal contains system timestamp information based on a time reference source and a first clock cumulative error of the wireless repeater, the first clock cumulative error is the total timing deviation of the wireless repeater's own clock source over time. The wireless terminal calculates and updates the local time reference based on the system timestamp information and the first clock cumulative error in the response signal, in combination with the sending time of the wake-up frame and the symbol length of the maximum length preamble, to complete the initial time synchronization between the wireless terminal and the wireless repeater, wherein the symbol length is determined by the communication data rate.

[0007] In combination with the first aspect, in a possible implementation, the synchronization state between the wireless terminal and the wireless repeater is maintained through periodic heartbeat communication, and the first clock cumulative error of the wireless repeater and the second clock cumulative error of the wireless terminal are monitored and calculated in real time, including: obtaining a time reference source in the wireless fire alarm controller, and presetting a periodic communication time slot in the wireless repeater based on the time reference source, and presetting a heartbeat period in the wireless terminal, wherein the time slot length is Tslot, the number is Ne, and the heartbeat period is associated with the system working period Tpatorduty. The wireless repeater communicates with the wireless fire alarm controller in the periodic communication time slot, and receives the downlink heartbeat broadcast response signal of the wireless fire alarm controller, which contains the timestamp data of the time reference source and the first clock cumulative error of the wireless repeater. The wireless terminal sends an uplink heartbeat data packet to the wireless repeater in the preset heartbeat period. The wireless repeater calculates the second clock cumulative error of the wireless terminal according to the time deviation between the time data of receiving the uplink heartbeat data packet and the start time of the corresponding predetermined heartbeat period, the second clock cumulative error being the cumulative deviation of the wireless terminal's own clock in ppm. The wireless repeater packs the time reference source, the first clock cumulative error of itself, and the calculated second clock cumulative error into a heartbeat response signal and returns it to the wireless terminal. The wireless terminal and the wireless repeater dynamically update their local time reference and cumulative error based on the information contained in the heartbeat response signal, to maintain the synchronization state between the wireless terminal and the wireless repeater.

[0008] In combination with the first aspect, in a possible implementation, the wireless terminal and the wireless repeater dynamically update their local time reference base and accumulated error according to the information contained in the heartbeat response signal, including: the wireless terminal extracts the time stamp data of the time reference source, the first clock accumulated error of the wireless repeater and the second clock accumulated error of the wireless terminal in the heartbeat response signal after receiving the heartbeat response signal. The wireless terminal calibrates its local absolute time reference base based on the time stamp data of the time reference source. The wireless terminal updates the first clock accumulated error of the wireless repeater carried in the heartbeat response signal as the current accumulated error value of the wireless repeater stored locally. The wireless terminal updates the second clock accumulated error of the wireless terminal carried in the heartbeat response signal as the current accumulated error value of itself. The wireless repeater continuously accumulates and updates its local first clock accumulated error value at a preset frequency based on the deviation of its internal clock source from the time reference source after sending the heartbeat response signal.

[0009] In combination with the first aspect, in a possible implementation, a dynamic synchronization processing model is constructed, including: based on the time reference source, the first clock accumulated error and the second clock accumulated error, a system clock accumulated total error is calculated. A clock drift prediction model containing the first clock accumulated error and the second clock accumulated error is established through the system clock accumulated total error with the time reference source as a reference, and the relative time deviation of the wireless repeater and the wireless terminal in the next communication period is predicted through the clock drift prediction model. Based on the predicted relative time deviation, a synchronization processing model for dynamically adjusting the communication timing is constructed, which is used to generate a low-power synchronization strategy including an optimized signal sending window and a shortened preamble length.

[0010] In combination with the first aspect, in a possible implementation, the time data of the next periodic scanning of the communication channel by the wireless repeater is predicted through the dynamic synchronization processing model to generate the low-power synchronization strategy, including: based on the relative time deviation predicted by the clock drift prediction model, the predicted time point T of the next periodic scanning of the communication channel by the wireless repeater is calculated through cadnext wherein T cal is the reference time base, N is an integer representing the number of scanning periods, T cadduty is the repeater scanning period. According to the sign and size relationship of the first clock accumulated error rxerr and the second clock accumulated error exerr, the predicted time point is adjusted to obtain the optimized signal sending window start time T nextsend . Based on the real-time first clock accumulated error rxerr and the second clock accumulated error exerr, the actual system clock accumulated total error T is calculated through xerr xerr ​​​and the first clock accumulated error of the relay, by calculating a preamble length compensation value T pcal and determining a shortened preamble length, wherein T rxerr is a relay error time calculated by T exerr is a terminal error time calculated by The optimized signal sending window starting time T nextsend and the shortened preamble length are combined to generate a low-power consumption synchronization strategy.

[0011] In combination with the first aspect, in a possible implementation, the predicted time point is adjusted according to the sign and size relationship between the first clock accumulated error rxerr and the second clock accumulated error exerr to obtain the optimized signal sending window starting time T nextsend , including: when exerr> rxerr, and exerr< 0, rxerr< 0, the optimized signal sending window starting time T nextsend = T cadnext . When exerr< rxerr, and exerr< 0, rxerr< 0, the optimized signal sending window starting time T nextsend = T cadnext (T rxerr T exerr） . When exerr> rxerr, and exerr> 0, rxerr> 0, the optimized signal sending window starting time T nextsend = T cadnext (T exerr T rxerr） . When exerr< rxerr, and exerr> 0, rxerr> 0, the optimized signal sending window starting time T nextsend = T cadnext . When exerr> rxerr, and exerr< 0, rxerr> 0, the optimized signal sending window starting time T nextsend = T cadnext + T rxerr . When exerr> rxerr, and exerr> 0, rxerr< 0, the optimized signal sending window starting time T nextsend = T cadnext T exerr T rxerrWhen exerr < rxerr, and exerr < 0, rxerr > 0, then the optimized signal transmission window start time T nextsend =T cadnext +T exerr When exerr < rxerr, and exerr > 0, rxerr < 0, then the optimized signal transmission window start time T nextsend =T cadnext T rxerr T exerr .

[0012] In conjunction with the first aspect mentioned above, in one possible implementation, the synchronization state includes an unconfigured state, a non-networked state, an asynchronous state, and a synchronized state. The wireless terminal transitions between these states based on the communication results with the wireless repeater. When the wireless terminal and wireless repeater are first manufactured or reset by an administrator, they enter the unconfigured state. When configuring the network for the unconfigured wireless terminal and repeater, they switch to the asynchronous state for initial synchronization. If a wireless terminal in the asynchronous state sends M uplink data packets without receiving an acknowledgment signal from the wireless repeater, it switches to the non-networked state and clears the locally stored time reference information and accumulated error information related to the wireless repeater, where M is a preset positive integer. If a wireless terminal in the synchronized state sends N uplink data packets without receiving an acknowledgment signal from the wireless repeater, it switches to the asynchronous state, where N is a preset positive integer. When the total cumulative error of the system clock calculated by the wireless terminal based on the first clock cumulative error and the second clock cumulative error, and the total cumulative error of the system clock exceeds the channel activity detection period of the wireless repeater, the wireless terminal is forcibly switched from the synchronous state to the asynchronous state.

[0013] In conjunction with the first aspect mentioned above, one possible implementation involves real-time monitoring of all communication results in the wireless repeater, dynamically maintaining or forcibly re-establishing the synchronization state based on the communication success rate. This includes: dynamically adjusting the heartbeat period of periodic heartbeat communication based on historical communication success rate evaluation results. When the communication success rate is lower than a preset first threshold, the heartbeat period is shortened to increase the synchronization calibration frequency. When the communication success rate is higher than a preset second threshold, the heartbeat period is extended to reduce power consumption. If the communication success rate remains lower than a preset third threshold after shortening the heartbeat period, it is determined that the link quality has deteriorated, triggering a forced synchronization state reconstruction process. The forced synchronization state reconstruction process includes switching the wireless terminal to an unconnected state, clearing all locally stored synchronization parameters, and re-initiating the initial synchronization process.

[0014] Secondly, a low-power bidirectional repeater device at the link level for a wireless fire alarm system is provided, comprising: a communication unit and a processing unit; the communication unit is used to perform signal transmission between a wireless terminal and a wireless repeater, including sending a wake-up frame, receiving an acknowledgment signal, and performing uplink and downlink data communication; the processing unit is used for the wireless terminal to perform initial synchronization with the wireless repeater using a maximum-length preamble, the duration of which covers the default channel activity detection period of the wireless repeater. Based on a time reference source provided by a wireless fire alarm controller, the synchronization state between the wireless terminal and the wireless repeater is maintained through preset periodic heartbeat communication, and the first clock cumulative error of the wireless repeater and the second clock cumulative error of the wireless terminal are monitored and calculated in real time. A dynamic synchronization processing model is constructed, and based on the synchronization state between the wireless terminal and the wireless repeater, the first clock cumulative error, and the second clock cumulative error, the time data for the next periodic scan of the communication channel by the wireless repeater is predicted through the dynamic synchronization processing model to generate a low-power synchronization strategy. The low-power synchronization strategy includes an optimized signal transmission window and a shortened preamble length. When a wireless terminal needs to send uplink alarm data or issue downlink control commands, a low-power synchronization strategy identifies the optimized signal transmission window and the shortened preamble length. When the identified signal transmission window is reached, the corresponding shortened preamble length is sent to complete the relay forwarding of uplink data or the reception and response of downlink data. All communication results in the wireless repeater are monitored in real time, and the synchronization state is dynamically maintained or forcibly rebuilt based on the communication success rate to ensure the stability of the communication link.

[0015] Thirdly, this application provides a low-power bidirectional repeater at the link level for a wireless fire alarm system, comprising: a processor and a storage medium; the storage medium includes instructions, and the processor is used to execute the instructions to implement the methods described in the first aspect and any possible implementation thereof. This low-power bidirectional repeater at the link level for a wireless fire alarm system can be an electronic device or a chip within an electronic device.

[0016] Fourthly, this application provides a computer-readable storage medium storing instructions that, when executed on a wireless fire alarm system link-level low-power bidirectional relay device, cause the wireless fire alarm system link-level low-power bidirectional relay device to perform the method described in the first aspect and any possible implementation thereof.

[0017] Fifthly, this application provides a computer program product containing instructions that, when the computer program product is run on a wireless fire alarm system link-level low-power bidirectional relay device, causes the wireless fire alarm system link-level low-power bidirectional relay device to perform the methods described in the first aspect and any possible implementation thereof.

[0018] This application provides a link-level low-power bidirectional repeater method for a wireless fire alarm system. It comprises a complete adaptive synchronization system consisting of a maximum-length preamble initial synchronization mechanism, periodic heartbeat communication and dual-clock error monitoring, a dynamic synchronization processing model, and a real-time detection and forced state reconstruction mechanism for communication results. This ensures reliable initial wake-up under unknown clock deviations through the maximum-length preamble initial synchronization mechanism, resolving synchronization failures caused by insufficient preamble length. Furthermore, it combines periodic heartbeat communication and dual-clock error monitoring based on a high-precision time base to track the clock drift of both the repeater and the terminal in real time, overcoming the limitations of single-clock calibration. This system addresses the shortcomings of error accumulation in heterogeneous devices, ensuring synchronization accuracy. Simultaneously, a dynamic synchronization processing model predicts the optimal communication window and generates a low-power strategy that shortens the preamble, reducing the use of long preambles, thus lowering energy consumption and ensuring communication reliability. Finally, a closed-loop control mechanism based on real-time detection of communication results and forced state reconstruction dynamically adjusts the heartbeat cycle or triggers resynchronization, effectively preventing communication interruptions caused by the inability to automatically recover from link quality deterioration. This reduces system power consumption while improving the real-time performance and reliability of bidirectional communication, solving the problems of high energy consumption in multi-level relays, large downlink command delays, and the inability to self-recover after link synchronization loss in wireless fire alarm systems.

[0019] It should be understood that the descriptions of technical features, technical solutions, beneficial effects, or similar language in this application do not imply that all features and advantages can be achieved in any single embodiment. Rather, it is understood that the description of a feature or beneficial effect means that a specific technical feature, technical solution, or beneficial effect is included in at least one embodiment. Therefore, the descriptions of technical features, technical solutions, or beneficial effects in this specification do not necessarily refer to the same embodiment. Furthermore, the technical features, technical solutions, and beneficial effects described in this embodiment can be combined in any suitable manner. Those skilled in the art will understand that embodiments can be implemented without one or more specific technical features, technical solutions, or beneficial effects of a particular embodiment. In other embodiments, additional technical features and beneficial effects may be identified in specific embodiments that do not embody all embodiments. Attached Figure Description

[0020] Figure 1 A system architecture diagram of a link-level low-power bidirectional relay system for a wireless fire alarm system provided in this application embodiment; Figure 2 A flowchart illustrating a link-level low-power bidirectional relay method for a wireless fire alarm system provided in this application embodiment; Figure 3A flowchart illustrating another link-level low-power bidirectional relay method for a wireless fire alarm system provided in this application embodiment; Figure 4 A flowchart illustrating another link-level low-power bidirectional relay method for a wireless fire alarm system provided in this application embodiment; Figure 5 This is a schematic diagram of the structure of a link-level low-power bidirectional relay device for a wireless fire alarm system, provided in an embodiment of this application. Detailed Implementation

[0021] In the description of this application, unless otherwise stated, " / " means "or," for example, A / B can mean A or B. The "and / or" in this document is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, and B alone. Furthermore, "at least one" means one or more, and "multiple" means two or more. The terms "first," "second," etc., do not limit the quantity or order of execution, and "first," "second," etc., do not necessarily imply differences.

[0022] It should be noted that, in this application, the terms "exemplary" or "for example" are used to indicate that something is being described as an example, illustration, or illustration. Any embodiment or design described as "exemplary" or "for example" in this application should not be construed as being more preferred or advantageous than other embodiments or design solutions. Specifically, the use of terms such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0023] To address the issue of existing technologies where, during initial connection or resynchronization after loss of synchronization, terminal devices use fixed-length preambles to send wake-up signals due to unknown clock deviations, the preamble length may not fully cover the repeater's entire channel scanning and detection cycle. This can easily lead to synchronization failures due to timing misalignment, requiring multiple attempts and increasing network access time and power consumption costs. Furthermore, the repeater and terminal devices use independent clock sources, resulting in inherent deviations in crystal oscillator accuracy that accumulate over time and with changes in ambient temperature. Unilateral clock synchronization cannot effectively compensate for this bidirectional, heterogeneous accumulated error, leading to gradual degradation of synchronization and ultimately communication link loss of synchronization. Additionally, to ensure the repeater can successfully wake up and receive data at unpredictable scanning times during operation, terminal devices typically need to continuously send long preamble wake-up frames or maintain prolonged listening while receiving downlink commands. This results in significant air interface transmission and reception power consumption, leading to short battery-powered repeaters and terminal devices that cannot meet the long-term reliable operation requirements of fire alarm systems. Downlink control commands (such as linkage instructions issued by the controller) need to be sent when the terminal device is in a sleep state. Either the command needs to wait until the terminal enters its next fixed, periodic listening window, or the repeater needs to continuously send long wake-up frames. It is impossible to accurately predict when the terminal will wake up, resulting in large downlink command response delays and poor real-time performance. When the communication link is interrupted due to signal interference, equipment failure, or excessive accumulated errors, manual intervention is required. It is impossible to dynamically judge the link status based on historical communication success rates, nor can it automatically trigger the reconstruction and synchronization process when the link quality continues to deteriorate. This leads to technical problems such as poor maintainability and robustness.This application provides a link-level low-power bidirectional relay method for a wireless fire alarm system. This method comprises a complete adaptive synchronization system consisting of a maximum-length preamble initial synchronization mechanism, periodic heartbeat communication and dual-clock error monitoring, a dynamic synchronization processing model, and a real-time communication result detection and state forced reconstruction mechanism. Before use, the maximum-length preamble initial synchronization mechanism ensures reliable initial wake-up under unknown clock deviations, resolving synchronization failures caused by insufficient preamble length. Furthermore, it combines periodic heartbeat communication based on a high-precision time base with dual-clock error monitoring to track the clock drift of both the repeater and the terminal in real time, overcoming the limitations of single-clock calibration. It cannot address the shortcomings of error accumulation in heterogeneous devices, thus failing to guarantee synchronization accuracy. Simultaneously, by using a dynamic synchronization processing model to predict the optimal communication window and generate a low-power strategy that shortens the preamble, the use of long preambles can be reduced, thereby lowering energy consumption and ensuring communication reliability. Finally, a closed-loop control system based on real-time detection of communication results and a forced state reconstruction mechanism dynamically adjusts the heartbeat cycle or triggers resynchronization, effectively avoiding communication interruptions caused by the inability to automatically recover from link quality deterioration. This reduces system power consumption while improving the real-time performance and reliability of bidirectional communication, solving the problems of high energy consumption in multi-level relays, large downlink command delays, and the inability to self-recover after link synchronization loss in wireless fire alarm systems.

[0024] like Figure 1 As shown in the embodiment of this application, a link-level low-power bidirectional relay method for a wireless fire alarm system includes: Step 101: The wireless terminal uses a maximum-length preamble to perform initial synchronization with the wireless repeater. The duration of the maximum-length preamble covers the default channel activity detection period of the wireless repeater.

[0025] In this context, a wireless terminal refers to the terminal equipment in a wireless fire alarm system, such as smoke detectors and manual alarm buttons. A wireless repeater is a relay device used to forward wireless signals. The maximum length preamble is a sequence used for synchronization in a communication frame, and its duration is set to the maximum to ensure reliable detection. Initial synchronization is the process by which the wireless terminal and the wireless repeater establish time synchronization for the first time. The default channel activity detection period is the interval at which the wireless repeater periodically scans the channel to detect signal activity.

[0026] In some implementations, during the initial synchronization process, the wireless terminal first generates a wake-up frame containing a maximum-length preamble. The duration of this preamble is designed to cover the wireless repeater's default channel activity detection period, typically not less than 2000 milliseconds, ensuring that the preamble is detected regardless of when the repeater begins listening during the scan period. The wireless terminal then transmits this wake-up frame on the channel. Meanwhile, the wireless repeater scans within the default channel activity detection period. When it detects the maximum-length preamble, it acknowledges receipt of the wake-up signal and returns an acknowledgment signal to the wireless terminal. This acknowledgment signal contains system timestamp information and clock error data. Finally, the wireless terminal calibrates its local time base based on the information in the acknowledgment signal, completing the initial synchronization with the wireless repeater.

[0027] It should be noted that the maximum preamble length is used to ensure that, during the initial synchronization phase, even if the scanning cycle of the wireless repeater and the timing of the terminal's transmission are not perfectly aligned, wake-up can still be achieved by covering the entire detection cycle, thus avoiding synchronization failure. Furthermore, after initial synchronization, a shorter preamble can be used to save power.

[0028] Step 102: Based on the time reference source provided by the wireless fire alarm controller, maintain the synchronization between the wireless terminal and the wireless repeater through preset periodic heartbeat communication, and monitor and calculate the first clock cumulative error of the wireless repeater and the second clock cumulative error of the wireless terminal in real time.

[0029] The wireless fire alarm controller is the core control device of the system, providing a precise time reference source. The time reference source is the standard time reference data emitted by the wireless fire alarm controller for synchronization of the entire system. Periodic heartbeat communication is a regular communication process between the terminal and the repeater to maintain synchronization. Synchronization status indicates that the terminal and the repeater's time reference are consistent. The first clock cumulative error is the sum of timing deviations (in ppm) generated by the wireless repeater's own clock source over time. The second clock cumulative error is the sum of timing deviations (in ppm) generated by the wireless terminal's own clock source over time.

[0030] In some implementations, a periodic heartbeat communication mechanism is first preset in the system based on a high-precision time reference source provided by the wireless fire alarm controller. At this time, the wireless repeater can communicate with the controller within a preset communication time slot and receive a heartbeat broadcast response containing a timestamp and a first clock cumulative error. At the same time, the wireless terminal can also send uplink heartbeat data packets to the repeater according to a preset heartbeat cycle. The second clock cumulative error of the terminal is calculated by the deviation between the time when the repeater receives the data packet and the expected time point. Then, the time reference source, the first clock cumulative error and the second clock cumulative error are packaged into a heartbeat response signal and returned to the terminal. Finally, the terminal and the repeater dynamically update their respective local time reference and cumulative error values ​​according to the information in the response signal, thereby maintaining a synchronized state.

[0031] It should be noted that both the repeater and the terminal's clock source have inherent errors, which accumulate over time and lead to synchronization issues. Therefore, periodic heartbeat communication is required for calibration. Furthermore, real-time monitoring and calculation of the first and second accumulated clock errors can accurately grasp the trend of time deviation changes, thus providing a data basis for subsequent synchronization strategy adjustments.

[0032] Synchronization states include unconfigured state, not connected to the network state, asynchronous state, and synchronized state, among which: The wireless terminal switches between unconfigured, non-networked, asynchronous, and synchronized states based on the communication results with the wireless repeater. When the wireless terminal and repeater are first manufactured or reset by the administrator, they enter the unconfigured state. When configuring a network for an unconfigured wireless terminal and repeater, the system switches to the asynchronous state for initial synchronization.

[0033] When a wireless terminal in an asynchronous state sends M uplink data packets without receiving a response signal from the wireless repeater, it switches to an unconnected state and clears the locally stored time reference information and accumulated error information related to the wireless repeater, where M is a preset positive integer.

[0034] When a wireless terminal in the synchronized state sends N uplink data packets without receiving a response signal from the wireless repeater, it switches to the asynchronous state, where N is a preset positive integer.

[0035] When the total cumulative error of the system clock calculated by the wireless terminal based on the first clock cumulative error and the second clock cumulative error, and the total cumulative error of the system clock exceeds the channel activity detection period of the wireless repeater, the wireless terminal is forcibly switched from the synchronous state to the asynchronous state.

[0036] The synchronization state refers to the operating state where the wireless terminal and the wireless repeater maintain a consistent time base. The unconfigured state is the initial state after the device is first manufactured or reset. The non-networked state is the state where the device cannot establish a valid connection with the repeater. The asynchronous state is the state where the device has been configured but has not yet completed time synchronization. The total accumulated error of the system clock is the total time deviation caused by the combined effect of the first and second accumulated clock errors. The channel activity detection period is the interval at which the wireless repeater scans the channel.

[0037] It should be noted that the state transition mechanism can improve robustness under different operating conditions. By presetting positive integers M and N, the sensitivity of state transition can be adjusted more flexibly. The forced state transition mechanism is to prevent communication failures caused by excessive clock errors, thus ensuring system reliability. The operation of clearing stored information avoids the continuous impact of erroneous data and provides clean initial conditions for re-establishing synchronization.

[0038] Step 103: Construct a dynamic synchronization processing model. Based on the synchronization status of the wireless terminal and the wireless repeater, the first clock cumulative error, and the second clock cumulative error, the dynamic synchronization processing model predicts the time data for the next periodic scan of the communication channel by the wireless repeater, generating a low-power synchronization strategy. The low-power synchronization strategy includes an optimized signal transmission window and a shortened preamble length.

[0039] The dynamic synchronization processing model is a mathematical model based on clock error prediction and synchronization state, used to optimize communication timing. Synchronization state represents the degree of time alignment between the terminal and the repeater. The low-power synchronization strategy is an energy-saving scheme implemented by optimizing communication parameters. The optimized signal transmission window is the optimal communication time period after timing adjustment. The shortened preamble length is an energy-saving measure to reduce the synchronization sequence length.

[0040] The construction of a dynamic synchronization processing model includes: Based on the time reference source, the first clock cumulative error, and the second clock cumulative error, the total cumulative error of the system clock is calculated.

[0041] Using a time reference source, a clock drift prediction model is established by accumulating the total error of the system clock, which includes the first clock accumulation error and the second clock accumulation error. The relative time deviation between the wireless repeater and the wireless terminal in the next communication cycle is then predicted using the clock drift prediction model.

[0042] Based on the predicted relative time deviation, a synchronization processing model is constructed for dynamically adjusting communication timing, which generates a low-power synchronization strategy including an optimized signal transmission window and a shortened preamble length.

[0043] Step 104: When the wireless terminal needs to send uplink alarm data or issue downlink control commands, it identifies the optimized signal transmission window and the shortened preamble length through a low-power synchronization strategy. When the time reaches the identified signal transmission window, it sends the corresponding shortened preamble length to complete the relay forwarding of uplink data or the reception and response of downlink data. The downlink control command processing includes switching to the downlink channel for data transmission.

[0044] Uplink alarm data consists of alarm information sent from the terminal to the repeater. Downlink control commands are control instructions sent from the repeater to the terminal. Uplink data relay forwarding is the repeater's processing of data forwarded from the terminal. Downlink data reception and response is the terminal's reception and processing of repeater instructions. The downlink channel is a dedicated communication channel used for transmitting control commands.

[0045] In some implementations, when a wireless terminal needs to send uplink alarm data or process downlink control commands, it first identifies the optimized signal transmission window and the shortened preamble length through a low-power synchronization strategy. Identifying the optimized signal transmission window ensures the accuracy of communication timing and avoids unnecessary waiting time. Furthermore, using the shortened preamble length reduces the energy consumption of each communication. Then, the system continuously monitors the time, and when the identified signal transmission window is reached, it immediately sends the corresponding shortened preamble length. Next, it completes the relay forwarding of uplink data or the reception and response of downlink data. Meanwhile, the channel switching mechanism during downlink control command processing ensures the isolation and reliability of uplink and downlink communication.

[0046] Step 105: Real-time detection of all communication results in the wireless repeater, and dynamic maintenance or forced reconstruction of synchronization state based on communication success rate to ensure the stability of communication link.

[0047] Real-time monitoring of all communication results in the wireless repeater, dynamically maintaining or forcibly re-establishing the synchronization state based on the communication success rate, including: Based on historical communication success rate assessment results, the heartbeat cycle of periodic heartbeat communication is dynamically adjusted.

[0048] When the communication success rate is lower than a preset first threshold, the heartbeat cycle is shortened to increase the synchronization calibration frequency.

[0049] When the communication success rate is higher than a preset second threshold, the heartbeat cycle is extended to reduce power consumption.

[0050] If the communication success rate remains below the preset third threshold after shortening the heartbeat cycle, the link quality is determined to have deteriorated, triggering a forced reconstruction of the synchronization state process.

[0051] The forced reconstruction of the synchronization state process includes switching the wireless terminal to an unconnected state, clearing all locally stored synchronization parameters, and restarting the initial synchronization process.

[0052] Real-time detection refers to the continuous monitoring and analysis of the communication process. Communication result refers to the success or failure status of each data transmission. Communication success rate is the ratio of successful communications to the total number of communications. Dynamic maintenance refers to adjusting synchronization parameters in real time based on changes in system state. Forced reconstruction refers to the process of actively triggering the re-establishment of the synchronization state. The communication link is the path channel for data transmission.

[0053] In some implementations, all communication results in the wireless repeater are first detected in real time, including successful and failed communication records. Then, the current communication success rate is calculated based on these results. The first, second, and third thresholds of the wireless fire alarm system are adaptively set according to the communication success rate for different usage scenarios. When the success rate is lower than the preset first threshold, the heartbeat cycle is shortened and the synchronization frequency is increased. When the success rate is higher than the preset second threshold, the heartbeat cycle is extended and power consumption is reduced. If the communication success rate is still lower than the preset third threshold after shortening the heartbeat cycle, the link quality is determined to be deteriorated, and a forced reconstruction of the synchronization state process is triggered. The synchronization state process includes switching the terminal to an unconnected state, clearing all locally stored synchronization parameters, and re-initiating the initial synchronization process.

[0054] Based on the above technical solution, a complete adaptive synchronization system is constructed by combining a maximum-length preamble initial synchronization mechanism, periodic heartbeat communication and dual-clock error monitoring, a dynamic synchronization processing model, and a real-time detection and state forced reconstruction mechanism for communication results. This system ensures reliable initial wake-up under unknown clock deviations by using a maximum-length preamble initial synchronization mechanism before use, resolving synchronization failures caused by insufficient preamble length. Furthermore, it is combined with periodic heartbeat communication and dual-clock error monitoring based on a high-precision time base to track clock drift of both the repeater and the terminal in real time, overcoming the limitations of single-clock calibration in handling the accumulation of errors from heterogeneous devices. This approach addresses the shortcomings of traditional methods, ensuring synchronization accuracy. Simultaneously, by using a dynamic synchronization processing model to predict the optimal communication window and generate a low-power strategy that shortens the preamble, the use of long preambles is reduced, thus lowering energy consumption and ensuring communication reliability. Finally, a closed-loop control mechanism based on real-time detection of communication results and forced state reconstruction dynamically adjusts the heartbeat cycle or triggers resynchronization, effectively preventing communication interruptions caused by the inability to automatically recover from link quality deterioration. This reduces system power consumption while improving the real-time performance and reliability of bidirectional communication, solving the problems of high energy consumption, large downlink command delays, and the inability to self-recover after link synchronization loss in wireless fire alarm systems.

[0055] In one possible implementation of the embodiments of this application, combined withFigure 1 ,like Figure 2 As shown, the initial synchronization between the wireless terminal and the wireless repeater using the maximum length preamble can be achieved through the following steps 201 to 203, which are explained in detail below: Step 201: The wireless terminal sends a wake-up frame with a preamble of maximum length to the wireless repeater. The duration of the maximum length preamble is not less than 2000 milliseconds.

[0056] The duration refers to the transmission time of the preamble, which shall be no less than 2000 milliseconds to cover the repeater’s default channel activity detection period.

[0057] In some implementations, the wireless terminal generates a wake-up frame containing a preamble of maximum length and lasting for no less than 2000 milliseconds during the initial synchronization phase. This avoids synchronization failures caused by clock skew, misaligned scanning timing, or environmental interference, and ensures that the preamble can be detected regardless of when the wireless repeater starts listening during the scanning cycle.

[0058] Step 202: After detecting the maximum length preamble by scanning the channel, the wireless repeater returns an acknowledgment signal to the wireless terminal. The acknowledgment signal contains system timestamp information based on the time reference source and the first clock cumulative error of the wireless repeater. The first clock cumulative error is the sum of timing deviations generated by the wireless repeater's own clock source over time, in ppm.

[0059] Among them, the system timestamp information is absolute time data based on a time reference source.

[0060] In some implementations, the wireless repeater scans within the default channel activity detection period. When it detects a wake-up frame with a preamble of maximum length sent by the wireless terminal, it confirms that a synchronization request has been received. Then, it generates an acknowledgment signal containing the system timestamp information from the time reference source obtained from the wireless fire alarm controller and the first clock cumulative error of the wireless repeater itself, and sends it back to the wireless terminal. This allows the wireless terminal to calculate and update its local time reference reference through the acknowledgment signal, thus completing the initial time synchronization.

[0061] Step 203: The wireless terminal calculates and updates the local time reference based on the system timestamp information in the response signal and the first clock cumulative error, combined with the sending time of the wake-up frame and the symbol length of the maximum length preamble, to complete the initial time synchronization between the wireless terminal and the wireless repeater. The symbol length is determined by the communication data rate.

[0062] The transmission time is the point in time when the wake-up frame transmission begins or ends, recorded locally by the wireless terminal. The symbol length is determined by the communication data rate and represents the transmission time of each symbol. The time reference base is the absolute time reference used locally by the wireless terminal to adjust the communication timing. Initial time synchronization is the process by which the wireless terminal and the wireless repeater establish time alignment for the first time.

[0063] In some implementations, after the wireless terminal receives the acknowledgment signal from the wireless repeater, it parses the system timestamp information and the first clock accumulated error. Then, combining the locally recorded wake-up frame, it calculates the symbol length, i.e., the transmission time and the symbol length of the maximum length preamble, based on the communication data rate. Next, the wireless terminal uses the system timestamp information as an absolute time reference and uses the first clock accumulated error for error compensation to calculate the deviation between the transmission time and the system time, thereby adjusting the local time reference. Finally, the wireless terminal updates its local absolute time reference, completing the initial time synchronization with the wireless repeater and ensuring the timing accuracy of subsequent communications.

[0064] Based on the above technical solution, the terminal's preamble generation module generates a long preamble wake-up frame and sends a preamble of maximum length with a duration of not less than 2000ms to ensure complete coverage of the repeater's channel scanning cycle. This ensures the absolute reliability of the initial wake-up and solves the wake-up failure problem that easily occurs with traditional short preambles in unknown clock states. Simultaneously, after the repeater's scanning detection module identifies the preamble, the time information processing module generates a response signal containing the system timestamp and clock error, providing the terminal with absolute time reference and error compensation data. Through bidirectional time information exchange, a high-precision time base and error compensation mechanism are provided, solving the problem of insufficient synchronization accuracy caused by the inability of a single clock synchronization to eliminate accumulated errors. Finally, the terminal's time synchronization algorithm module performs comprehensive calculations by combining the sending time, symbol length (dynamically determined by the communication data rate), timestamp, and clock error to establish a precise local time reference base. This enables adaptive data rate time synchronization, solving the problem of insufficient flexibility caused by fixed parameter synchronization being unable to adapt to different communication rates and improving high-precision initial synchronization between heterogeneous devices.

[0065] In one possible implementation of this application embodiment, maintaining the synchronization state between the wireless terminal and the wireless repeater through periodic heartbeat communication, and real-time monitoring and calculation of the first clock cumulative error of the wireless repeater and the second clock cumulative error of the wireless terminal can be achieved through the following steps 301 to 306, which are described in detail below: Step 301: Obtain the time reference source in the wireless fire alarm controller, and based on the time reference source, preset periodic communication time slots in the wireless repeater, and preset the heartbeat cycle in the wireless terminal, wherein the time slot length is Tslot, the number is Ne, and the heartbeat cycle is related to the system working cycle Tpatorlduty.

[0066] The periodic communication time slot is a pre-defined periodic communication time interval in the wireless repeater based on a time reference source, with a slot length of Tslot and a quantity of Ne. The heartbeat period is a pre-defined time interval for periodically sending heartbeat data packets in the wireless terminal. The system operating cycle Tpatorlduty is the overall operating cycle time of the system, and the heartbeat period is related to the system operating cycle Tpatorlduty.

[0067] In some implementations, the wireless fire alarm controller provides a time reference source as a synchronization reference, and then presets periodic communication time slots in the wireless repeater based on the time reference source. These time slots have a fixed length Tslot and a number Ne to ensure that the repeater communicates with the controller regularly. At the same time, a heartbeat cycle is preset in the wireless terminal, which is associated with the system working cycle Tpatorlduty, so that the timing of the terminal's heartbeat transmission is synchronized with the overall working rhythm of the system, thereby maintaining time alignment and communication reliability between the terminal and the repeater.

[0068] It should be noted that pre-setting periodic communication time slots and heartbeat cycles helps reduce errors caused by clock drift. By associating the system working cycle with the system's operating cycle, the communication frequency can be dynamically adjusted to balance power consumption and real-time performance, ensuring low-power and reliable two-way communication in the fire alarm system.

[0069] Step 302: During the periodic communication time slot, the wireless repeater communicates with the wireless fire alarm controller and receives the downlink heartbeat broadcast response signal from the wireless fire alarm controller. The downlink heartbeat broadcast response signal contains the timestamp data of the time reference source and the first clock cumulative error of the wireless repeater.

[0070] Among them, the downlink heartbeat broadcast response signal is a signal containing synchronization information sent by the wireless fire alarm controller.

[0071] In some implementations, the wireless repeater actively communicates with the wireless fire alarm controller during preset periodic communication time slots; at this time, the wireless fire alarm controller will respond and send a downlink heartbeat broadcast response signal; when the wireless repeater receives the downlink heartbeat broadcast response signal containing timestamp data of the time reference source and the first clock cumulative error of the wireless repeater, the received data can be used for time synchronization and error calibration, thereby maintaining the time consistency of the system.

[0072] It should be noted that during its operation, the wireless repeater is allowed to periodically obtain authoritative time references and its own clock error information, thereby effectively reducing synchronization deviations caused by clock drift, ensuring low power consumption and reliable communication in the fire alarm system, and dynamically maintaining the repeater's clock accuracy through a downlink heartbeat mechanism.

[0073] Step 303: The wireless terminal sends an uplink heartbeat data packet to the wireless repeater during a preset heartbeat cycle.

[0074] The wireless terminal can initiate the communication process periodically according to a preset heartbeat cycle to generate an uplink heartbeat data packet containing device status information; then the wireless terminal sends the uplink heartbeat data packet to the wireless repeater through the wireless channel; at this time, the wireless repeater will receive and process this uplink heartbeat data packet.

[0075] In some implementations, by periodically sending uplink heartbeat data packets, the wireless terminal can maintain time synchronization with the wireless repeater, while providing the wireless repeater with the basic data for calculating the terminal's clock error.

[0076] Step 304: The wireless repeater calculates the second clock cumulative error of the wireless terminal based on the time deviation between the time data of receiving the uplink heartbeat data packet and the start time of the corresponding predetermined heartbeat cycle. The second clock cumulative error refers to the cumulative clock deviation of the wireless terminal itself in ppm.

[0077] In some implementations, the wireless repeater receives uplink heartbeat data packets sent by the wireless terminal and records the reception time data; then it compares the actual reception time with the corresponding predetermined heartbeat cycle start time and calculates the time deviation between the two; based on the calculated time deviation value and the system running time, the time deviation is converted into a second clock cumulative error in ppm using an error calculation formula; and the calculated second clock cumulative error value is stored and used for subsequent synchronization strategy adjustments.

[0078] Step 305: The wireless repeater packages the time reference source, its own first clock cumulative error, and the calculated second clock cumulative error into a heartbeat response signal and returns it to the wireless terminal.

[0079] Packaging refers to the process of combining multiple data elements into a complete data packet.

[0080] In some implementations, the wireless repeater obtains data from the time reference source from local storage and reads its own first clock cumulative error value and second clock cumulative error value; then it packages and combines these data according to a predetermined protocol format to form a complete heartbeat response signal; the wireless repeater then sends this heartbeat response signal back to the wireless terminal through the wireless channel, completing the entire response process.

[0081] Step 306: The wireless terminal and the wireless repeater dynamically update their respective local time reference base and cumulative error based on the information contained in the heartbeat response signal, so as to maintain the synchronization status of the wireless terminal and the wireless repeater.

[0082] The wireless terminal and wireless repeater dynamically update their respective local time reference base and accumulated error based on the information contained in the heartbeat response signal, including: After receiving the heartbeat response signal, the wireless terminal extracts the timestamp data of the time reference source, the first clock cumulative error of the wireless repeater, and the second clock cumulative error of the wireless terminal from the heartbeat response signal.

[0083] The wireless terminal calibrates its local absolute time reference based on the timestamp data from the time reference source.

[0084] The wireless terminal updates the first clock cumulative error of the wireless repeater carried in the heartbeat response signal to the current cumulative error value of the wireless repeater stored locally.

[0085] The wireless terminal updates its own current cumulative error value to the second clock cumulative error carried in the heartbeat response signal.

[0086] After sending a heartbeat response signal, the wireless repeater continuously accumulates and updates its local first clock accumulated error value at a preset frequency based on the deviation between its internal clock source and time reference source.

[0087] In some implementations, the preset frequency refers to a pre-set error update frequency.

[0088] It should be noted that after receiving the heartbeat response signal, the wireless terminal immediately parses and extracts the timestamp data of the time reference source, the first clock cumulative error of the wireless repeater, and the second clock cumulative error of the wireless terminal. Based on the extracted timestamp data of the time reference source, the local absolute time reference is calibrated to ensure the consistency of the time reference. At the same time, the wireless terminal updates the first clock cumulative error of the wireless repeater carried in the heartbeat response signal to the current cumulative error value of the wireless repeater stored locally; and updates the second clock cumulative error of the wireless terminal carried in the heartbeat response signal to its own current cumulative error value. Finally, after sending the heartbeat response signal, based on the deviation between its internal clock source and the time reference source, it continuously accumulates and updates its local first clock cumulative error value at a preset frequency, thereby completing bidirectional dynamic error update and synchronization maintenance.

[0089] Based on the above technical solution, by having the controller provide a unified time reference source, the repeater can preset periodic communication time slots (time slot length Tslot, number Ne) based on the reference. The terminal sends uplink data according to the heartbeat cycle associated with the system working cycle Tpatorlduty. This allows the repeater to receive the heartbeat signal containing the timestamp and the first clock accumulated error sent by the controller within the communication time slot. This significantly reduces system power consumption through a hierarchical synchronization mechanism. The terminal and repeater only wake up to communicate within the preset time slot, avoiding continuous monitoring and energy consumption. At the same time, by monitoring the time deviation of the terminal's uplink data packets, the second clock accumulated error is calculated, forming a two-way error compensation mechanism. The clock drift is offset by ppm-level error calculation and dynamic updates, improving synchronization accuracy. The above three types of data are packaged into a heartbeat response signal and returned to the terminal. The terminal and repeater can then dynamically update their local time reference and accumulated error accordingly, forming a closed-loop synchronization control to ensure link stability and make its synchronization state self-adaptively maintainable.

[0090] In one possible implementation of this application embodiment, the low-power synchronization strategy is generated by predicting the time data of the next periodic scan of the communication channel by the wireless repeater through a dynamic synchronization processing model. This can be achieved through the following steps 401 to 405, which are described in detail below: Step 401: Based on the relative time deviation predicted by the clock drift prediction model, through... Calculate the predicted time point T for the next periodic scan of the communication channel by the wireless repeater. cadnext T cal It is the reference time base, N is an integer representing the number of scan cycles, T cadduty It is the relay scan cycle.

[0091] The clock drift prediction model is a mathematical model based on a time reference source, the first clock cumulative error, and the second clock cumulative error. It is used to predict the relative time deviation between the wireless repeater and the wireless terminal in the next communication cycle. The relative time deviation refers to the time offset between the wireless repeater and the wireless terminal due to the clock cumulative error. The predicted time point is the estimated time point for the next periodic scan of the communication channel by the wireless repeater. The reference time reference is a high-precision time source provided by the wireless fire alarm controller. The number of scan cycles refers to the integer N, representing the Nth scan cycle. The relay scan cycle is the fixed time interval for the wireless repeater to periodically scan the communication channel.

[0092] In some implementations, the clock drift prediction model is first input with a time reference source, a first clock cumulative error, a second clock cumulative error, a relay scan period, the number of scan periods, and the current time at the time of calculation. This allows the model to calculate the theoretical time point for the next periodic scan of the communication channel by the wireless repeater. By calculating the relay error time and the terminal error time, the cumulative error in ppm units is converted to a specific time span. Finally, the total cumulative error of the system clock is calculated and output, thus representing the total deviation after the superposition of the two clock errors. At this point, the formula can be used... Calculate the predicted time point T for the next periodic scan of the communication channel by the wireless repeater. cadnext .

[0093] Step 402: Based on the sign and magnitude relationship between the first clock cumulative error rxerr and the second clock cumulative error exerr, adjust the prediction time point to obtain the optimized signal transmission window start time T. nextsend .

[0094] The positive or negative sign indicates whether the clock is too fast or too slow. The optimized signal transmission window start time Tnextsend is the best signal transmission start time obtained by adjusting the predicted time point based on the relationship between the signs and magnitudes of the accumulated errors of the two clocks.

[0095] Based on the sign and magnitude relationship between the first clock cumulative error rxerr and the second clock cumulative error exerr, the prediction time point is adjusted to obtain the optimized signal transmission window start time T. nextsend ,include: If exerr > rxerr and exerr < 0, rxerr < 0, then the optimized signal transmission window start time T nextsend =T cadnext .

[0096] If exerr < rxerr, and exerr < 0, rxerr < 0, then the optimized signal transmission window start time T nextsend =Tcadnext (T rxerr T exerr） .

[0097] If exerr > rxerr, and exerr > 0, rxerr > 0, then the optimized signal transmission window start time T nextsend =T cadnext (T exerr T rxerr） .

[0098] If exerr < rxerr, and exerr > 0, rxerr > 0, then the optimized signal transmission window start time T nextsend =T cadnext .

[0099] If exerr > rxerr and exerr < 0, rxerr > 0, then the optimized signal transmission window start time T nextsend =T cadnext +T rxerr .

[0100] When exerr > rxerr, and exerr > 0, rxerr < 0, then the optimized signal transmission window start time T nextsend =T cadnext T exerr T rxerr .

[0101] If exerr < rxerr and exerr < 0, rxerr > 0, then the optimized signal transmission window start time T nextsend =T cadnext +T exerr .

[0102] When exerr < rxerr, and exerr > 0, rxerr < 0, then the optimized signal transmission window start time T nextsend =T cadnext T rxerr T exerr .

[0103] Among them, the relay error time T rxerr and terminal error time T exerr These are intermediate calculation parameters that convert error values ​​in ppm units into specific time values.

[0104] In some implementations, based on the values ​​and signs of the first clock cumulative error rxerr and the second clock cumulative error exerr obtained from real-time monitoring, the optimized signal transmission window start time T can be adaptively obtained according to the different values ​​and signs. nextsend .

[0105] Step 403: Based on the real-time first clock cumulative error rxerr and the second clock cumulative error exerr, through... The actual system clock cumulative total error T is calculated. xerr .

[0106] In some implementations, the total error value is obtained by adding the values ​​of the first clock cumulative error rxerr and the second clock cumulative error exerr, which are obtained from real-time monitoring; and the predicted time point T for the next periodic scan of the communication channel by the wireless repeater is obtained. cadnext and reference time base T cal Calculate the time difference (T) between these two time points. cadnext -T cal） Finally, through the formula The actual system clock cumulative total error T is calculated. xerr This represents the total time deviation caused by the combined clock errors of the two devices over the time span from the reference time to the predicted scan time.

[0107] Step 404: Accumulate total error T based on real-time system clock xerr The first clock accumulation error of the repeater, through Calculate the preamble length compensation value T pcal And determine the shortened preamble length, where T rxerr Through The calculated relay error time, T exerr Through The calculated terminal error time.

[0108] Among them, the preamble length compensation value T pcal This refers to the amount of time that needs to be added or reduced from the basic preamble length to compensate for accumulated clock errors, ensuring reliable communication synchronization. The shortened preamble length refers to the optimal preamble duration determined by a formula based on the preamble length compensation value.

[0109] In some implementations, first through The calculated relay error time T rxerr Then through The calculated terminal error time T exerr This can be based on the accumulated total error T of the real-time system clock.xerr The first clock cumulative error rxerr of the repeater is obtained through the formula Calculate the preamble length compensation value and, in conjunction with the symbol time Tsymb of the communication system (determined by the communication data rate), use the formula... The shortened preamble length is determined, where 8 is the minimum preamble length that the relay needs to detect to receive the wake-up frame, 6 is the minimum number of symbols required by the receiver hardware to detect the preamble, and CadToRxSymb is the transition time from channel activity detection to reception state; then the optimized preamble length is finally obtained, which significantly reduces power consumption while ensuring communication reliability.

[0110] It should be noted that the calculation of the preamble length compensation value uses 2×T rxerr +T exerr The formula effectively covers the maximum clock drift error, ensuring communication reliability. Furthermore, when determining the shortened preamble length, the max function ensures that the preamble length will not fall below the minimum value of 8 symbols specified by the physical layer.

[0111] Step 405: Set the optimized signal transmission window start time T nextsend By combining the shortened preamble length, a low-power synchronization strategy is generated.

[0112] Among them, the low-power synchronization strategy refers to a communication scheme that combines the optimized signal transmission window start time and the shortened preamble length, which can maintain communication reliability while reducing system power consumption.

[0113] In some implementations, the optimized signal transmission window start time T is calculated using a dynamic synchronization processing model. nextsend This can be based on the accumulated total error T of the real-time system clock. xerr The first clock cumulative error rxerr of the repeater is expressed by formula T. pcal =2×T rxerr +T exerr Calculate the preamble length compensation value and further determine the shortened preamble length; then, adjust the optimized signal transmission window start time T. nextsend By combining and packaging the shortened preamble length, a complete low-power synchronization strategy is formed, which includes precise transmission timing in the time dimension and optimized preamble length in the physical layer dimension. Together, these constitute a complete solution for realizing low-power bidirectional communication.

[0114] It should be noted that the generation of the low-power synchronization strategy is a dynamic adjustment process, which is updated in real time according to changes in clock error.

[0115] Based on the above technical solution, a clock drift prediction model is used to predict the relative time deviation based on a time reference source and the cumulative error of the two clocks, calculating the predicted time point for the next scan of the repeater. Then, fine-tuning is performed according to eight scenarios of the sign and magnitude relationship of the cumulative errors of the two clocks to obtain the optimized signal transmission window start time. Simultaneously, the total cumulative error of the system clock is calculated in real time, and the preamble length compensation value is calculated in combination with the repeater error to determine the shortened preamble length. Finally, the optimized time window and the shortened preamble are combined to generate a low-power synchronization strategy. This solution can jointly solve the problems of high energy consumption caused by using fixed-length preambles and static communication timing, the problem of reduced communication reliability caused by insufficient clock drift compensation, and the problem of bidirectional communication that traditional solutions cannot simultaneously take into account the real-time performance of uplink alarm and downlink control commands. Thus, the service life of battery-powered repeater equipment is significantly extended while ensuring the reliable operation of the fire alarm system.

[0116] The above primarily describes the solutions of the embodiments of this application from the perspective of device implementation. It is understood that each device, for example, a low-power bidirectional relay device at the link level for a wireless fire alarm system, includes at least one of the hardware structures and software modules corresponding to each function in order to achieve the above-mentioned functions. Those skilled in the art should readily recognize that, based on the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein, this application can be implemented in hardware or a combination of hardware and computer software. Whether a function is implemented in hardware or by computer software driving hardware depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0117] This application embodiment can divide the link-level low-power bidirectional relay device of the wireless fire alarm system into functional units according to the above method example. For example, each function can be divided into a separate functional unit, or two or more functions can be integrated into the same processing unit. The integrated unit can be implemented in hardware or as a software functional unit. It should be noted that the unit division in this application embodiment is illustrative and only represents one logical functional division. In actual implementation, there may be other division methods.

[0118] When using integrated units, Figure 5A possible structural schematic diagram of a low-power bidirectional relay device at the link level of a wireless fire alarm system (referred to as a low-power bidirectional relay device 50 at the link level of a wireless fire alarm system) involved in the above embodiments is shown. The low-power bidirectional relay device 50 at the link level of a wireless fire alarm system includes a processing unit 501 and a communication unit 502, and may also include a storage unit 503. Figure 5 The schematic diagram shown can be used to illustrate the structure of the link-level low-power bidirectional relay device of the wireless fire alarm system involved in the above embodiments.

[0119] when Figure 5 The schematic diagram shown illustrates the structure of the low-power bidirectional relay device at the link level of the wireless fire alarm system involved in the above embodiments. The processing unit 501 is used to control and manage the operation of the low-power bidirectional relay device at the link level of the wireless fire alarm system. The communication unit 502 is used for the low-power bidirectional relay device at the link level of the wireless fire alarm system to communicate with other devices. The storage unit 503 is used to store the program code and data of the low-power bidirectional relay device at the link level of the wireless fire alarm system.

[0120] For example, communication unit 502 is used to perform signal transmission between a wireless terminal and a wireless repeater, including sending a wake-up frame, receiving an acknowledgment signal, and performing uplink and downlink data communication. Processing unit 501 is used for initial synchronization between the wireless terminal and the wireless repeater using a preamble of maximum length. The duration of the maximum-length preamble covers the default channel activity detection period of the wireless repeater. Based on the time reference source provided by the wireless fire alarm controller, the synchronization state between the wireless terminal and the wireless repeater is maintained through preset periodic heartbeat communication. The first clock cumulative error of the wireless repeater and the second clock cumulative error of the wireless terminal are monitored and calculated in real time. A dynamic synchronization processing model is constructed. Based on the synchronization state between the wireless terminal and the wireless repeater, the first clock cumulative error, and the second clock cumulative error, the dynamic synchronization processing model predicts the time data for the next periodic scan of the communication channel by the wireless repeater and generates a low-power synchronization strategy. The low-power synchronization strategy includes an optimized signal transmission window and a shortened preamble length. When the wireless terminal needs to send uplink alarm data or issue downlink control commands, the optimized signal transmission window and the shortened preamble length are identified through the low-power synchronization strategy. When the identified signal transmission window is reached, the corresponding shortened preamble length is sent to complete the relay forwarding of uplink data or the reception and response of downlink data. It monitors all communication results in the wireless repeater in real time and dynamically maintains or forces the reconstruction of the synchronization state based on the communication success rate to ensure the stability of the communication link.

[0121] In one possible implementation, the processing unit 501 is further configured to perform initial synchronization between the wireless terminal and the wireless repeater using a maximum-length preamble, including: the wireless terminal sending a wake-up frame with a maximum-length preamble to the wireless repeater, the duration of which is not less than 2000 milliseconds. After detecting the maximum-length preamble by scanning the channel, the wireless repeater returns an acknowledgment signal to the wireless terminal. The acknowledgment signal contains system timestamp information based on a time reference source and the first clock accumulated error of the wireless repeater. The first clock accumulated error is the sum of timing deviations generated by the wireless repeater's own clock source over time, measured in ppm. Based on the system timestamp information and the first clock accumulated error in the acknowledgment signal, combined with the transmission time of the wake-up frame and the symbol length of the maximum-length preamble, the wireless terminal calculates and updates its local time reference, completing the initial time synchronization between the wireless terminal and the wireless repeater, wherein the symbol length is determined by the communication data rate.

[0122] In one possible implementation, the processing unit 501 is further configured to maintain the synchronization between the wireless terminal and the wireless repeater through periodic heartbeat communication, and to monitor and calculate the first clock cumulative error of the wireless repeater and the second clock cumulative error of the wireless terminal in real time. This includes: acquiring a time reference source in the wireless fire alarm controller, and presetting periodic communication time slots in the wireless repeater based on the time reference source, and presetting a heartbeat period in the wireless terminal, wherein the time slot length is Tslot, the number is Ne, and the heartbeat period is associated with the system operating cycle Tpatorlduty. During the periodic communication time slots, the wireless repeater communicates with the wireless fire alarm controller and receives a downlink heartbeat broadcast response signal from the wireless fire alarm controller. The downlink heartbeat broadcast response signal contains timestamp data from the time reference source and the first clock cumulative error of the wireless repeater. During the preset heartbeat period, the wireless terminal sends an uplink heartbeat data packet to the wireless repeater. The wireless repeater calculates the second clock cumulative error of the wireless terminal based on the time deviation between the received uplink heartbeat data packet time and the start of the corresponding predetermined heartbeat cycle. The second clock cumulative error refers to the wireless terminal's own clock cumulative deviation, expressed in ppm. The wireless repeater packages the time reference source, its own first clock cumulative error, and the calculated second clock cumulative error into a heartbeat response signal and returns it to the wireless terminal. Based on the information contained in the heartbeat response signal, both the wireless terminal and the wireless repeater dynamically update their respective local time references and cumulative errors, maintaining synchronization between them.

[0123] In one possible implementation, the processing unit 501 is further configured to dynamically update the local time reference and accumulated error of the wireless terminal and the wireless repeater based on the information contained in the heartbeat response signal. This includes: after receiving the heartbeat response signal, the wireless terminal extracts the timestamp data of the time reference source, the first clock accumulated error of the wireless repeater, and the second clock accumulated error of the wireless terminal from the heartbeat response signal. The wireless terminal calibrates its local absolute time reference based on the timestamp data of the time reference source. The wireless terminal updates the first clock accumulated error of the wireless repeater carried in the heartbeat response signal to the current accumulated error value of the wireless repeater stored locally. The wireless terminal updates the second clock accumulated error of the wireless terminal carried in the heartbeat response signal to its own current accumulated error value. After sending the heartbeat response signal, the wireless repeater continuously accumulates and updates its local first clock accumulated error value at a preset frequency based on the deviation between its internal clock source and the time reference source.

[0124] In one possible implementation, processing unit 501 is further configured to construct a dynamic synchronization processing model, including: calculating the total cumulative error of the system clock based on a time reference source, a first cumulative clock error, and a second cumulative clock error; establishing a clock drift prediction model that includes the first and second cumulative clock errors using the total cumulative error of the system clock, with the time reference source as a reference, and predicting the relative time deviation between the wireless repeater and the wireless terminal in the next communication cycle using the clock drift prediction model; and constructing a synchronization processing model for dynamically adjusting communication timing based on the predicted relative time deviation, which generates a low-power synchronization strategy including an optimized signal transmission window and a shortened preamble length.

[0125] In one possible implementation, the processing unit 501 is further configured to predict the time data of the next periodic scan of the communication channel by the wireless repeater through a dynamic synchronization processing model, and generate a low-power synchronization strategy, including: based on the relative time deviation predicted by the clock drift prediction model, through... Calculate the predicted time point T for the next periodic scan of the communication channel by the wireless repeater. cadnext T cal It is the reference time base, N is an integer representing the number of scan cycles, T cadduty This is the relay scan cycle. Based on the sign and magnitude relationship between the first clock cumulative error rxerr and the second clock cumulative error exerr, the prediction time point is adjusted to obtain the optimized signal transmission window start time T. nextsend Based on the real-time first clock cumulative error rxerr and the second clock cumulative error exerr, through The actual system clock cumulative total error T is calculated. xerr Based on the cumulative total error T of the real-time system clock. xerrThe first clock accumulation error of the repeater, through Calculate the preamble length compensation value T pcal And determine the shortened preamble length, where T rxerr Through The calculated relay error time, T exerr Through The calculated terminal error time. The optimized signal transmission window start time T. nextsend By combining the shortened preamble length, a low-power synchronization strategy is generated.

[0126] In one possible implementation, the processing unit 501 is further configured to adjust the prediction time point to obtain the optimized signal transmission window start time T based on the sign and magnitude relationship between the first clock cumulative error rxerr and the second clock cumulative error exerr. nextsend This includes: when exerr > rxerr and exerr < 0, rxerr < 0, then the optimized signal transmission window start time T nextsend =T cadnext When exerr < rxerr, and exerr < 0, rxerr < 0, then the optimized signal transmission window start time T nextsend =T cadnext (T rxerr T exerr） When exerr > rxerr, and exerr > 0, rxerr > 0, then the optimized signal transmission window start time T nextsend =T cadnext (T exerr T rxerr） When exerr < rxerr, and exerr > 0, rxerr > 0, then the optimized signal transmission window start time T nextsend =T cadnext When exerr > rxerr and exerr < 0, rxerr > 0, then the optimized signal transmission window start time T nextsend =T cadnext +T rxerr When exerr > rxerr, and exerr > 0, rxerr < 0, then the optimized signal transmission window start time T nextsend =T cadnext T exerr T rxerrWhen exerr < rxerr, and exerr < 0, rxerr > 0, then the optimized signal transmission window start time T nextsend =T cadnext +T exerr When exerr < rxerr, and exerr > 0, rxerr < 0, then the optimized signal transmission window start time T nextsend =T cadnext T rxerr T exerr .

[0127] In one possible implementation, the processing unit 501 is further configured to synchronize states including unconfigured state, non-networked state, asynchronous state, and synchronized state, wherein: the wireless terminal switches between these states based on the communication results with the wireless repeater. When the wireless terminal and wireless repeater are first manufactured or reset by an administrator, they enter the unconfigured state. When configuring the wireless terminal and wireless repeater in the unconfigured state for network setup, they switch to the asynchronous state for initial synchronization. When a wireless terminal in the asynchronous state continuously sends M uplink data packets without receiving an acknowledgment signal from the wireless repeater, it switches to the non-networked state and clears the locally stored time reference information and accumulated error information related to the wireless repeater, where M is a preset positive integer. When a wireless terminal in the synchronized state continuously sends N uplink data packets without receiving an acknowledgment signal from the wireless repeater, it switches to the asynchronous state, where N is a preset positive integer. When the total cumulative error of the system clock calculated by the wireless terminal based on the first clock cumulative error and the second clock cumulative error, and the total cumulative error of the system clock exceeds the channel activity detection period of the wireless repeater, the wireless terminal is forcibly switched from the synchronous state to the asynchronous state.

[0128] In one possible implementation, the processing unit 501 is further configured to detect all communication results in the wireless repeater in real time, and dynamically maintain or forcibly rebuild the synchronization state based on the communication success rate. This includes: dynamically adjusting the heartbeat period of periodic heartbeat communication based on historical communication success rate evaluation results. When the communication success rate is lower than a preset first threshold, the heartbeat period is shortened to increase the synchronization calibration frequency. When the communication success rate is higher than a preset second threshold, the heartbeat period is extended to reduce power consumption. If the communication success rate remains lower than a preset third threshold after shortening the heartbeat period, it is determined that the link quality has deteriorated, triggering a forced synchronization state rebuilding process. The forced synchronization state rebuilding process includes switching the wireless terminal to an unconnected state, clearing all locally stored synchronization parameters, and re-initiating the initial synchronization process.

[0129] The processing unit 501 can be a processor or a controller, and the communication unit 502 can be a communication interface, transceiver, transceiver circuit, transceiver device, etc. The term "communication interface" is a general term and may include one or more interfaces. The storage unit 503 can be a memory. When the low-power bidirectional relay device 50 of the wireless fire alarm system link level is a chip, the processing unit 501 can be a processor or a controller, and the communication unit 502 can be an input interface and / or an output interface, pins, or circuits, etc. The storage unit 503 can be a storage unit within the chip (e.g., a register, cache, etc.) or a storage unit located outside the chip (e.g., read-only memory (ROM), random access memory (RAM, etc.)).

[0130] The communication unit can also be called a transceiver unit. The antenna and control circuit with transceiver functions in the wireless fire alarm system link-level low-power bidirectional repeater 50 can be considered as the communication unit 502 of the wireless fire alarm system link-level low-power bidirectional repeater 50, and the processor with processing functions can be considered as the processing unit 501 of the wireless fire alarm system link-level low-power bidirectional repeater 50. Optionally, the device in the communication unit 502 used to implement the receiving function can be considered as the communication unit, which is used to execute the receiving steps in the embodiments of this application. The communication unit can be a receiver, a receiver circuit, etc. The device in the communication unit 502 used to implement the transmitting function can be considered as the transmitting unit, which is used to execute the transmitting steps in the embodiments of this application. The transmitting unit can be a transmitter, a transmitter, a transmitting circuit, etc.

[0131] Although this application has been described herein in conjunction with various embodiments, those skilled in the art, by reviewing the accompanying drawings, the disclosure, and the appended claims, will understand and implement other variations of the disclosed embodiments in carrying out the claimed application. In the claims, the word "comprising" does not exclude other components or steps, and "a" or "an" does not exclude multiple components. A single processor or other unit can implement several functions listed in the claims. While different dependent claims may recite certain measures, this does not mean that these measures cannot be combined to produce good results.

[0132] Although this application has been described in conjunction with specific features and embodiments, it is obvious that various modifications and combinations can be made thereto without departing from the spirit and scope of this application. Accordingly, this specification and drawings are merely illustrative descriptions of the application as defined by the appended claims, and are considered to cover any and all modifications, variations, combinations, or equivalents within the scope of this application. Clearly, those skilled in the art can make various alterations and modifications to this application without departing from the spirit and scope of this application. Thus, if such modifications and variations of this application fall within the scope of the claims of this application and their equivalents, this application is also intended to include such modifications and variations.

Claims

1. A wireless fire alarm system link level low power bi-directional repeating method, characterized by, The wireless terminal uses a maximum length preamble to perform initial synchronization with the wireless repeater, and a duration of the maximum length preamble covers a default channel activity detection period of the wireless repeater. The wireless terminal and the wireless repeater maintain a synchronization state through a preset periodic heartbeat communication based on a time reference source provided by the wireless fire alarm controller, and real-time monitoring and calculation of a first clock cumulative error of the wireless repeater and a second clock cumulative error of the wireless terminal are performed. A dynamic synchronization processing model is constructed, and based on the synchronization state, the first clock cumulative error and the second clock cumulative error of the wireless terminal and the wireless repeater, time data of a next periodic scanning communication channel of the wireless repeater is predicted through the dynamic synchronization processing model, and a low-power consumption synchronization strategy is generated. The low-power consumption synchronization strategy includes an optimized signal transmission window and a shortened preamble length. When the wireless terminal needs to send uplink alarm data or issue a downlink control command, the low-power consumption synchronization strategy is used to identify the optimized signal transmission window and the shortened preamble length, and when time arrives at the identified signal transmission window, a corresponding shortened preamble length is sent, and relay forwarding of uplink data or reception and response of downlink data are completed, wherein downlink control command processing includes switching to a downlink channel for data transmission. Real-time detection of all communication results in the wireless repeater is performed, and the synchronization state is dynamically maintained or forcibly reconstructed based on a communication success rate, so as to ensure stability of a communication link. The wireless terminal uses a maximum length preamble to perform initial synchronization with the wireless repeater, and a duration of the maximum length preamble covers a default channel activity detection period of the wireless repeater.

2. A wireless fire alarm system link level low power bi-directional repeating method according to claim 1, wherein, The wireless repeater returns a response signal to the wireless terminal after detecting the maximum length preamble through scanning of a channel, and the response signal contains system timestamp information based on a time reference source and a first clock cumulative error of the wireless repeater, and the first clock cumulative error is a total timing deviation of a clock source of the wireless repeater itself over time. The wireless terminal calculates and updates a local time reference reference according to the system timestamp information and the first clock cumulative error in the response signal, and combines a transmission time of the wake-up frame and a symbol length of the maximum length preamble, to complete initial time synchronization between the wireless terminal and the wireless repeater, and the symbol length is determined by a communication data rate. The wireless terminal and the wireless repeater maintain a synchronization state through a preset periodic heartbeat communication, and real-time monitoring and calculation of a first clock cumulative error of the wireless repeater and a second clock cumulative error of the wireless terminal are performed, including: A time reference source in a wireless fire alarm controller is acquired, and a periodic communication time slot is preset in the wireless repeater and a heartbeat period is preset in the wireless terminal based on the time reference source, and a time slot length is Tslot and a quantity is Ne, and the heartbeat period is associated with a system working period Tpatorlduty.

3. A wireless fire alarm system link level low power bi-directional repeating method according to claim 2, wherein, ​ ​ The wireless repeater communicates with the wireless fire alarm controller in a periodic communication time slot and receives a downlink heartbeat broadcast response signal of the wireless fire alarm controller, wherein the downlink heartbeat broadcast response signal contains timestamp data of a time reference source and a first clock cumulative error of the wireless repeater; The wireless terminal sends an uplink heartbeat data packet to the wireless repeater in a preset heartbeat period; The wireless repeater calculates a second clock cumulative error of the wireless terminal according to a time deviation between time data of receiving the uplink heartbeat data packet and a start point of a corresponding predetermined heartbeat period, wherein the second clock cumulative error refers to a cumulative deviation of a clock of the wireless terminal itself in ppm; The wireless repeater packs the time reference source, the first clock cumulative error of itself and the calculated second clock cumulative error into a heartbeat response signal and returns to the wireless terminal; The wireless terminal and the wireless repeater dynamically update local time reference bases and cumulative errors of each other according to information contained in the heartbeat response signal, so as to maintain a synchronization state of the wireless terminal and the wireless repeater.

4. A wireless fire alarm system link level low power bi-directional repeating method according to claim 3, wherein, The wireless terminal and the wireless repeater dynamically update local time reference bases and cumulative errors of each other according to information contained in the heartbeat response signal, and the method comprises the following steps: After receiving the heartbeat response signal, the wireless terminal extracts timestamp data of a time reference source, a first clock cumulative error of the wireless repeater and a second clock cumulative error of the wireless terminal in the heartbeat response signal; The wireless terminal calibrates a local absolute time reference base thereof based on the timestamp data of the time reference source; The wireless terminal updates the first clock cumulative error of the wireless repeater carried in the heartbeat response signal as a current cumulative error value of the wireless repeater stored locally; The wireless terminal updates the second clock cumulative error of the wireless terminal carried in the heartbeat response signal as a current cumulative error value of itself; After sending the heartbeat response signal, the wireless repeater continuously accumulates and updates a local first clock cumulative error value thereof based on a deviation between an internal clock source thereof and the time reference source at a preset frequency.

5. A wireless fire alarm system link level low power bi-directional repeating method according to claim 4, wherein, The method for constructing a dynamic synchronization processing model comprises the following steps: calculating a system clock cumulative total error based on the time reference source, the first clock cumulative error and the second clock cumulative error; establishing a clock drift prediction model containing the first clock cumulative error and the second clock cumulative error through the system clock cumulative total error with the time reference source as a reference, and predicting a relative time deviation of the wireless repeater and the wireless terminal in a next communication period through the clock drift prediction model; constructing a synchronization processing model for dynamically adjusting a communication time sequence based on the predicted relative time deviation, so as to generate a low-power consumption synchronization strategy including an optimized signal sending window and a shortened preamble length.

6. A wireless fire alarm system link level low power bi-directional repeating method according to claim 5, wherein, The method for generating a low-power consumption synchronization strategy by predicting time data of a next periodic scanning communication channel of the wireless repeater through the dynamic synchronization processing model comprises the following steps: predicting a relative time deviation based on the clock drift prediction model, by calculating a predicted time point T at which the wireless repeater is to perform a next periodic scan of the communication channel cadnext where T cal is a reference time reference, N is an integer representing a number of scan periods, T cadduty is a repeater scan period; According to the sign and size relation of the first clock accumulated error rxerr and the second clock accumulated error exerr, the predicted time point is adjusted to obtain an optimized signal sending window starting time T nextsend ; Based on the real-time first clock cumulative error rxerr and the second clock cumulative error exerr, the actual system clock cumulative total error T is calculated by xerr ;​ based on the real-time system clock accumulated total error T xerr and the first clock accumulated error of the repeater, by calculating a preamble length compensation value T pcal and determining a shortened preamble length, wherein T rxerr is the repeater error time calculated by T exerr is the terminal error time calculated by ​ combining the optimized signal transmission window start time T nextsend and the shortened preamble length, generates the low power synchronization strategy.

7. A wireless fire alarm system link level low power bi-directional repeating method according to claim 6, wherein, The sign and size relationship of the first clock accumulated error rxerr and the second clock accumulated error exerr is used to adjust the predicted time point to obtain an optimized signal sending window start time T nextsend , comprising: When exerr > rxerr, and exerr < 0, rxerr < 0, the optimized signal sending window start time T nextsend = T cadnext ; When exerr < rxerr, and exerr < 0, rxerr < 0, the optimized signal sending window start time T nextsend = T cadnext (T rxerr T exerr） ; When exerr > rxerr, and exerr > 0, rxerr > 0, the optimized signal sending window start time T nextsend = T cadnext (T exerr T rxerr） ; When exerr < rxerr, and exerr > 0, rxerr > 0, the optimized signal sending window start time T nextsend = T cadnext ; When exerr > rxerr, and exerr < 0, rxerr > 0, the optimized signal sending window start time T nextsend = T cadnext + T rxerr ; When exerr > rxerr, and exerr > 0, rxerr < 0, the optimized signal sending window start time T nextsend = T cadnext T exerr T rxerr ; When exerr < rxerr, and exerr < 0, rxerr > 0, the optimized signal sending window start time T nextsend = T cadnext + T exerr ; When exerr < rxerr, and exerr > 0, rxerr < 0, the optimized signal sending window start time T nextsend = T cadnext T rxerr T exerr .

8. A wireless fire alarm system link level low power bi-directional repeating method according to claim 7, wherein, The synchronization state includes an unconfigured state, an uncommissioned state, an unsynchronized state and a synchronized state, wherein: The wireless terminal switches between the unconfigured state, the uncommissioned state, the unsynchronized state and the synchronized state according to the communication result with the wireless repeater; the wireless terminal and the wireless repeater enter the unconfigured state when they are first manufactured or reset by an administrator; the wireless terminal and the wireless repeater in the unconfigured state are configured for networking, and then switched to the unsynchronized state for initial synchronization operation; When the wireless terminal in the unsynchronized state continuously sends M uplink data packets, and none of the M uplink data packets receives a response signal from the wireless repeater, the wireless terminal switches to the uncommissioned state, and clears the locally stored time reference information and accumulated error information related to the wireless repeater, wherein M is a preset positive integer; When the wireless terminal in the synchronized state continuously sends N uplink data packets, and none of the N uplink data packets receives a response signal from the wireless repeater, the wireless terminal switches to the unsynchronized state, wherein N is a preset positive integer; When the system clock accumulated total error calculated by the wireless terminal based on the first clock accumulated error and the second clock accumulated error exceeds the channel activity detection period of the wireless repeater, the wireless terminal is forced to switch from the synchronized state to the unsynchronized state.

9. A wireless fire alarm system link level low power bi-directional repeating method according to claim 8, wherein, The real-time detection of all communication results in the wireless repeater, dynamic maintenance or forced reconstruction of the synchronization state based on the communication success rate, includes: Based on the historical communication success rate evaluation result, dynamically adjusting the heartbeat period of the periodic heartbeat communication; When the communication success rate is lower than a preset first threshold, the heartbeat period is shortened to increase the synchronization calibration frequency; When the communication success rate is higher than a preset second threshold, the heartbeat period is lengthened to reduce power consumption; If the communication success rate continues to be lower than a preset third threshold after the heartbeat period is shortened, it is determined that the link quality is deteriorating, and a forced reconstruction of the synchronization state process is triggered; The forced reconstruction of the synchronization state process includes switching the wireless terminal to the uncommissioned state, clearing all locally stored synchronization parameters, and reinitiating the initial synchronization process.

10. A wireless fire alarm system link level low power bidirectional repeater device, characterized by The device includes a communication unit and a processing unit; The communication unit is used to perform signal transmission between the wireless terminal and the wireless repeater, including sending a wake-up frame, receiving a response signal, and performing uplink and downlink data communication; The processing unit is used for the wireless terminal to use a maximum length preamble to perform initial synchronization with the wireless repeater, and the duration of the maximum length preamble covers the default channel activity detection period of the wireless repeater; Based on the time reference source provided by the wireless fire alarm controller, the synchronization state between the wireless terminal and the wireless repeater is maintained through the preset periodic heartbeat communication, and the first clock accumulated error of the wireless repeater and the second clock accumulated error of the wireless terminal are real-time monitored and calculated; A dynamic synchronization processing model is constructed, and based on the synchronization state of the wireless terminal and the wireless repeater, the first clock cumulative error and the second clock cumulative error, the time data of the next periodic scanning of the communication channel by the wireless repeater is predicted through the dynamic synchronization processing model, and a low-power consumption synchronization strategy is generated; the low-power consumption synchronization strategy includes an optimized signal sending window and a shortened preamble length; When the wireless terminal needs to send uplink alarm data or issue a downlink control command, the optimized signal sending window and the shortened preamble length are identified through the low-power consumption synchronization strategy, and when the time arrives at the identified signal sending window, the corresponding shortened preamble length is sent, and the relay forwarding of the uplink data or the reception and response of the downlink data are completed; All communication results in the wireless repeater are detected in real time, and the synchronization state is dynamically maintained or forcibly reconstructed based on the communication success rate, so as to ensure the stability of the communication link.

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