Data slice recombination order-preserving method based on Beidou short message

Abstract

The invention discloses a data slice recombination order-preserving method based on a Beidou short message, which relates to the technical field of data transmission and recombination optimization, and ensures the stability and low error rate of data in the transmission process by dynamically optimizing the size and quantity of slices according to channel bandwidth and delay through a self-adaptive slice adjustment mechanism. A unique serial number identifier and a first check code attached to each fragment are beneficial to identifying data under a complex channel condition, and errors and chaos in a recombination process are reduced. At a receiving end, a conflict analysis model is constructed by analyzing sequence offset and delay conditions of fragment arrival in real time, and a multi-layer correction instruction is provided according to an overall conflict rate and a time sequence consistency coefficient. The order-preserving mechanism ensures that the original order of the data can be maintained even in a complex network environment by preferentially processing the unlocked fragment and generating a retransmission instruction of the lost fragment. The combination of dynamic priority adjustment and a retransmission mechanism promotes the structure of the original data after recombination.

Description

Technical Field

[0001] The present invention relates to the technical field of data transmission and recombination optimization, and specifically to a method for data slice recombination and order preservation based on Beidou short messages. Background Art

[0002] In modern communication technologies, especially in the fields of satellite communication and low-orbit satellite communication, the reliability and efficiency of data transmission are key issues. With the continuous increase in the amount of information, traditional data transmission methods face challenges in multiple aspects such as bandwidth, latency, and bit error rate, especially in low-bandwidth and high-latency network environments such as the Beidou short message system. In order to ensure the reliability and sequential consistency of data during transmission, how to effectively slice, transmit, recombine, and ensure the order of data is an important research direction in current technologies.

[0003] In practical applications, due to the instability of the channel quality, problems such as data loss, out-of-order, and latency fluctuations may occur during data transmission, which will affect the performance of the system and even cause the data to be unable to be correctly received and used. In traditional data slicing methods, each slice is usually transmitted independently. If the network quality is poor, some slices may fail to be successfully transmitted due to channel problems (such as signal interference, packet loss, latency, etc.), resulting in data loss. Due to the instability of the network environment, data slices may be transmitted on different paths, resulting in their disordered arrival at the receiving end. Especially in the case of multi-path transmission or network congestion, data segments may be out of order.

[0004] Therefore, there is an urgent need to propose a method for data slice recombination and order preservation based on the Beidou short message system. Through technical means such as adaptive slicing adjustment, recombination analysis, and order preservation mechanism, it ensures that data can be effectively and reliably transmitted and the original data order can be restored in an unstable network environment. Summary of the Invention

[0005] Aiming at the deficiencies of the prior art, the present invention provides a method for data slice recombination and order preservation based on Beidou short messages to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention is realized through the following technical solutions: A method for data slice recombination and order preservation based on Beidou short messages, including the following steps:

[0007] S1. Adaptive slice adjustment: Before channel transmission, slice and fragment the original data to be sent, collect the current channel quality parameters and bandwidth status parameters, establish the first data set, construct the safety margin factor a, calculate and obtain the optimal fragment size Dsz and the number of fragments Nsz according to the margin factor a, and attach a unique serial number identifier and the first check code to each fragment through dynamically adjusted fragment size and number, generate the original serial number order, and upload the preprocessed fragment data to the Beidou satellite system;

[0008] S2. Reorganization analysis: At the receiving end, receive the fragment data and perform reorganization analysis according to the original serial number order, collect the arrival delay and fragment order offset of each fragment during the transmission process, construct a conflict analysis model based on this reorganization information, calculate the arrival order deviation Cpb, the overall conflict rate Ctz and the timing consistency coefficient Tsj of each fragment reorganization. When the overall conflict rate Ctz exceeds the preset conflict threshold, send the first correction instruction. When the timing consistency coefficient Tsj is lower than the stable threshold, send the channel adjustment instruction and the second timing correction instruction, and construct a data reorganization analysis set;

[0009] S3. Order preservation mechanism: Receive the second timing correction instruction, implement the order preservation mechanism, and perform data order correction using the arrival order deviation Cpb and the timing consistency coefficient Tsj; When there are conflicts or abnormal arrival orders for multiple fragments, give priority to processing the fragments whose data content is not locked, and adjust the order according to the priority to ensure that the reorganized data conforms to the original sequence order, forming a reorganized data stream. For the detected missing fragments, the system generates a retransmission instruction;

[0010] S4. Adaptive retransmission: Based on the retransmission instruction generated in the reorganization analysis set constructed in step S3, trigger the adaptive retransmission mechanism; The adaptive retransmission mechanism combines the safety margin factor a, dynamically adjusts the number of retransmissions Rcs and the retransmission interval Rtg and reorders the data after retransmitting the fragments, and repeats steps S3 and S4 until the reorganized data stream is successfully reorganized.

[0011] Preferably, S1 includes:

[0012] S11. Prepare the original data to be sent for fragment processing;

[0013] S12. Before data slicing, collect the channel quality parameters and bandwidth status parameters of the current channel in real time, and summarize them to form the first data set;

[0014] S12 specifically includes: S121. Directly measure the channel signal power by a power sensor to obtain the signal strength S;

[0015] S122. Measure the actual bandwidth usage by a network monitoring tool to obtain the real-time bandwidth utilization rate Br;

[0016] S123. Obtain the bit error rate Eb by statistically calculating the ratio of the number of error bits ccb to the total number of bits zbt at the receiving end:

[0017]

[0018] S124. Collect the noise power N in the noise detector, combine it with the signal strength S, and calculate the interference index J through the following formula:

[0019]

[0020] The first data set includes the signal strength S, the bit error rate Eb, the interference index J, the maximum bandwidth Bmax, and the real-time bandwidth utilization rate Br.

[0021] Preferably, S1 further includes:

[0022] S13. Within a fixed time window, the time window is set to 1 second; and within the time window, sample the signal strength S multiple times to obtain a set of signal strength data: S1, S2,..., S n , and calculate the signal strength mean S through the following formula:

[0023]

[0024] In the formula, S i represents the signal strength obtained at the i-th sampling time, and n represents the number of samplings;

[0025] S14. Based on a set of signal strength data, calculate the signal strength variance through the following formula

[0026]

[0027] S15. Combine the signal strength mean S and the signal strength variance Calculate the signal fluctuation coefficient σ through the following formula c :

[0028]

[0029] Among them, when the signal fluctuation coefficient σ c has a high value, it indicates that the signal strength is unstable and fluctuates greatly; while when the signal fluctuation coefficient σ c has a low value, the signal is relatively stable.

[0030] Preferably, S1 further includes: S16. Extract the bit error rate Eb, the interference index J, and the signal fluctuation coefficient σ c , after dimensionless processing, calculate the safety margin factor a through the following formula:

[0031] a = 1 + β * (σ c + J + Eb);

[0032] Among them, the adjustment coefficient β is used to adjust the sensitivity of the safety margin factor a, and its value range is 0.1 - 0.3;

[0033] S17. According to the channel and bandwidth status, calculate the optimal fragment size Dsz using the following formula:

[0034]

[0035] Among them, J is the interference index, the higher it is, the smaller the fragment size; Eb is the bit error rate, the higher it is, the smaller the fragment size; T limit is the maximum allowed transmission time;

[0036] S18. Collect the total size D of the data packets to be transmitted total , and calculate the number of fragments Nsz based on the total size D of the data packets total and the optimal fragment size Dsz:

[0037]

[0038] S19. Add a unique sequence number identifier to each fragment for sorting during data recombination, and generate and append a first check code for each fragment, including CRC check code;

[0039] Integrate the fragment size, quantity, sequence number identifier, and first check code to form a complete fragmented data packet, and upload the preprocessed fragmented data sequentially through the channel interface of the Beidou satellite system for transmission.

[0040] Preferably, S2 includes:

[0041] S21. Continuously receive the fragmented data from the Beidou short message system, and each received fragment contains a unique sequence number identifier and a first check code; the receiving end sorts the fragments in a predetermined order according to the sequence number identifier of each fragment to ensure that it can identify whether a fragment is lost or arrives in order, uses the first check code to detect the integrity of the fragment, and determines whether there is a bit error. If a bit error or data loss is detected, record the status of the fragment and mark it as "lost" or "to be retransmitted"; if the sequence number identifiers of the fragments are not continuous, it is considered that the fragment is lost, and record the number of lost fragments L;

[0042] S22. Record the timestamp T i when each fragment arrives at the receiving end, which is used to calculate the arrival delay d i of each fragment:

[0043] d i = Ti -T send (i);

[0044] where T send (i) is the transmission time of slice i;

[0045] S23. For each received slice, perform error code monitoring, sort the slice data according to the sequence number identifier, record the arrival time of each slice, and calculate the arrival delay of each slice; record the sequence offset of each slice, that is, the difference between the actual arrival order and the ideal order, for analyzing the sequence offset situation, and the arrival order deviation amount Cpb:

[0046]

[0047] In the formula, m represents the total number of slices received by the receiving end, O i is the actual arrival order of the i-th slice, and E i is the ideal arrival order of the i-th slice;

[0048] S24. Based on the recorded arrival delay, sequence deviation, and loss status information, calculate the overall conflict rate Ctz:

[0049]

[0050] where Cpb i is the arrival order deviation amount of each slice, L i is the number of lost slices in the i-th monitoring, and m represents the total number of slices received by the receiving end.

[0051] Preferably, S2 further includes:

[0052] S25. Analyze the time, location, and number of lost slices where conflicts occur, construct a conflict frequency distribution model using a multi-layer perceptron MLP and train it, calculate the standard deviation of the arrival delays of all slices, and obtain the delay index Yczs:

[0053]

[0054] In the formula, d i represents the arrival delay time of the i-th slice, d represents the average arrival delay time of the slices, and m represents the total number of slices received by the receiving end;

[0055] S26. According to the delay index Yczs, calculate and obtain the timing consistency coefficient Tsj through the following formula:

[0056]

[0057] In the formula, δ maxIndicates the maximum allowable delay. The timing consistency coefficient Tsj ranges from 0 to 1. The closer the value is to 1, the more consistent the arrival time of the shards is, and the more stable the delay is. If Tsj is close to 0, it indicates that the delay fluctuation is large, which may increase the difficulty of reorganizing the data order.

[0058] S27. Preset a conflict threshold, compare the conflict rate Ctz with the preset conflict threshold, and obtain the first evaluation result, including:

[0059] When the overall conflict rate Ctz > the conflict threshold, it indicates that there is a serious conflict risk during the reorganization process, and a first correction instruction is generated.

[0060] When the overall conflict rate Ctz ≤ the conflict threshold, it indicates that there is no serious conflict risk during the reorganization process.

[0061] S28. Preset the stability threshold to 0.8, compare the timing consistency coefficient Tsj with the stability threshold to evaluate the time consistency of the overall data stream, and obtain the second evaluation result, including:

[0062] If the timing consistency coefficient Tsj > 0.8, it indicates that the shard transmission delay fluctuation is normal.

[0063] If the timing consistency coefficient Tsj ≤ 0.8, it indicates that the shard transmission delay fluctuation is abnormal, and a channel adjustment instruction and a second timing correction instruction are generated. The channel adjustment instruction includes: increasing the transmission power of the current signal by 20%-30%, installing an anti-interference suppressor or a frequency hopping device, reducing the interference index J by 50%, and increasing the bandwidth by 20%-30%.

[0064] Preferably, S3 includes:

[0065] S31. After receiving the first correction instruction, count the number of lost shards L and the sequence deviation amount Cpb, classify the conflict types. If the sequence deviation is large, it is classified as a sequence conflict, and if a shard is lost, it is a loss conflict, and construct a data reorganization analysis set.

[0066] S32. During the data reorganization analysis process, screen out high-deviation shards. When the sequence deviation amount Cpb exceeds the preset deviation threshold, the system marks this shard as "sequence abnormal" and records the serial number identifier of this shard.

[0067] S33. When receiving the second timing correction instruction, the system marks the shards in the time period when the timing consistency coefficient Ts ≤ 0.8 as: "timing inconsistent" and records the serial number identifiers of the shards in this time period.

[0068] During the second timing correction instruction process, the system checks the locking status of each shard, and preferentially processes the shards in the "unlocked" state. These shards are not occupied by other operations and are convenient for preferential correction;

[0069] Sort the shards in the "unlocked" locking state, and preferentially restore them to the correct order. Perform the first-priority correction on the deviation amount Cpd from small to large;

[0070] S34. After the first-priority correction, sort the delay index Yczs from small to large to obtain the second-priority correction list, and perform the second-priority correction;

[0071] After the first-priority correction and the second-priority correction, the system forms a reorganized data stream in the corrected order; for the shards detected as missing, the system generates a retransmission instruction.

[0072] Preferably, step S4 includes:

[0073] S41. Trigger the adaptive retransmission mechanism based on the retransmission instruction generated in the reorganized analysis set constructed in step S3;

[0074] S42. Calculate and obtain the shard group interval factor G based on the number of shards Ccsl and the density in the current retransmission group:

[0075]

[0076] In the formula, Ccsl is the number of shards in the current retransmission group, and T group is the average arrival time interval of the shards in the current retransmission group;

[0077] S43. The adaptive retransmission mechanism combines the safety margin factor a, the bit error rate Eb, the interference index J, and the real-time bandwidth utilization rate Br in step S1. After dimensionless processing, calculate and obtain the retransmission times Rcs and the retransmission interval Rtg through the following formula:

[0078]

[0079] The meaning of the formula is that the higher the real-time bandwidth utilization rate Br and the signal strength S, the fewer the retransmission times can be; G represents the shard group interval factor.

[0080] Preferably, step S4 further includes:

[0081] S44. After retransmitting the shards according to the retransmission times Rcs and the retransmission interval Rtg, perform a second sequential correction on all the arrived shards based on the sequence number identifier. After repeating step S3, calibrate the position of the retransmitted shards in the reorganized data stream;

[0082] S45. Re-verify the entire reorganized data stream. If the verification passes, confirm that the data reorganization is complete; if the verification fails, repeat step S3 to generate a new retransmission instruction, re-trigger the adaptive retransmission mechanism, and go through verification until the reorganized data stream is successfully reorganized.

[0083] Preferably, the step of re-verifying the entire reorganized data stream in S45 is as follows:

[0084] S451. Check each received shard to verify its integrity and confirm whether there are any missing shards through the sequence number identifier.

[0085] S452. Check whether the sequence number identifiers of all shards have been correctly received and reorganized. After each retransmission, check whether the retransmitted data arrives on time and update the retransmission status during reorganization.

[0086] S453. Check whether there are any missing or unreorganizable shards.

[0087] For the missing shards, trigger a new retransmission request, that is, go back to step S31 for re-analysis and generation of a new retransmission instruction; if there are missing shards, record the sequence number identifiers of the missing shards and regenerate the retransmission instruction.

[0088] S454. Sort the received data using the sequence number identifiers of the shards and compare whether the order of the sorted data is consistent with the original sequence number identifier order.

[0089] S455. Perform verification on the reorganized data at the receiving end, generate a second checksum for each shard data, the second checksum includes CRC or hash value, and check whether the checksum of the shard data is consistent with the first checksum. If the second checksum is inconsistent, mark it as verification failure and request retransmission of this shard.

[0090] S456. If there are any verification failures, generate a new retransmission instruction and re-trigger the adaptive retransmission mechanism, repeat the verification process of the above S451 - 455 steps until successful reorganization.

[0091] The present invention provides a method for data slice reorganization and order preservation based on Beidou short messages. It has the following beneficial effects:

[0092] (1) The method for data slice recombination and order preservation based on Beidou short messages slices and fragments the original data to be sent before channel transmission, and real-time collects channel quality parameters and bandwidth status. By establishing a safety margin factor a, the optimal slice size Dsz and the number of slices Nsz are calculated to dynamically adjust the size and number of slices. Each slice is attached with a unique sequence number identifier and a first check code, so as to ensure that each slice can be independently identified during transmission, which is convenient for later recombination. This adaptive slice adjustment mechanism enables the slice size and number to be optimized according to actual network conditions such as bandwidth and delay, effectively reducing the error rate and out-of-order problems during the later recombination process.

[0093] (2) In step S2, after the receiving end receives the sliced data, it first performs recombination analysis according to the original sequence number order, collects the arrival delay and sequence offset of each slice, uses this information to construct a conflict analysis model, and calculates the slice arrival order deviation Cpb, the overall conflict rate Ctz, and the timing consistency coefficient Tsj. When the overall conflict rate Ctz exceeds the preset conflict threshold, a first correction instruction is issued. When the timing consistency coefficient Tsj is lower than the stable threshold, a channel adjustment instruction and a second timing correction instruction are issued, and a data recombination analysis set is constructed; and the state of the transmission channel is optimized. This step effectively detects and diagnoses problems in data transmission by real-time analyzing the arrival order and deviation of slices. Issuing conflict analysis and channel adjustment instructions in advance can timely respond to network congestion or transmission errors, avoid data loss and out-of-order, and improve the accuracy of data recombination.

[0094] (3) When the system detects that multiple slices are out of order or in conflict in S3, it will give priority to processing those unlocked slices and adjust the order according to the priority. This mechanism ensures that the order of the data can be correctly restored after all slices are received, avoiding recombination failure caused by out-of-order data. For the detected missing slices, the system will generate a retransmission instruction. The order preservation mechanism ensures that the order of the recombined data completely conforms to the original data order. Even in a complex and unstable network environment, the consistency and integrity of the data can be guaranteed. By dynamically adjusting the priority and timely retransmitting the missing slices, the accurate recovery of the data is ensured.

[0095] (4) During the recombination process, in combination with the recombination analysis result and the safety margin factor a, the number of retransmissions Rcs, the retransmission interval Rtg are dynamically adjusted, and the order is corrected again after retransmission. This process will continue until the recombined data stream is successfully restored. The adaptive retransmission mechanism automatically adjusts the retransmission strategy according to the network state and channel quality, effectively solving the problems of data loss or retransmission delay. The flexibility of the retransmission strategy greatly improves the reliability and orderliness of data transmission. Description of the Drawings

[0096] Figure 1Schematic diagram of the steps of the method for reorganizing and preserving the order of data slices based on Beidou short messages according to the present invention. Specific implementation mode

[0097] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0098] Embodiment 1

[0099] Please refer to Figure 1 , the present invention provides a method for reorganizing and preserving the order of data slices based on Beidou short messages, including the following steps:

[0100] S1. Adaptive slicing adjustment: Before channel transmission, slice and fragment the original data to be sent, collect the current channel quality parameters and bandwidth status parameters, establish a first data set, construct a safety margin factor a, calculate and obtain the optimal slice size Dsz and the number of slices Nsz according to the margin factor a, and attach a unique serial number identifier and a first check code to each slice through dynamically adjusted slice size and number to generate the original serial number order. The preprocessed sliced data is uploaded to the Beidou satellite system;

[0101] S2. Reorganization analysis: At the receiving end, receive the sliced data and perform reorganization analysis according to the original serial number order, collect the arrival delay and slice order offset of each slice during the transmission process, construct a conflict analysis model based on the reorganization information, calculate the arrival order deviation amount Cpb, the overall conflict rate Ctz and the timing consistency coefficient Tsj of each slice reorganization. When the overall conflict rate Ctz exceeds the preset conflict threshold, issue a first correction instruction. When the timing consistency coefficient Tsj is lower than the stable threshold, issue a channel adjustment instruction and a second timing correction instruction, and construct a data reorganization analysis set;

[0102] S3. Order preservation mechanism: Receive the second timing correction instruction, implement the order preservation mechanism, and perform data order correction using the arrival order deviation amount Cpb and the timing consistency coefficient Tsj; When there are conflicts or abnormal arrival orders for multiple slices, give priority to processing the slices whose data content has not been locked, and adjust the order according to the priority to ensure that the reorganized data conforms to the original sequence order, forming a reorganized data stream. For the detected missing slices, the system generates a retransmission instruction;

[0103] S4. Adaptive Retransmission: Trigger the adaptive retransmission mechanism based on the retransmission instructions generated from the reconstructed analysis set constructed in step S3; the adaptive retransmission mechanism combines the safety margin factor a to dynamically adjust the retransmission times Rcs, the retransmission interval Rtg, and perform reordering again after retransmission fragmentation, and repeat steps S3 and S4 until the reconstructed data stream is successfully reconstructed.

[0104] In this embodiment, before channel transmission, the original data to be sent is sliced and fragmented, and the channel quality parameters and bandwidth status are collected in real time. By establishing a safety margin factor a, the optimal fragmentation size Dsz and the number of fragments Nsz are calculated to dynamically adjust the size and number of fragments. Each slice is attached with a unique sequence number identifier and a check code, so as to ensure that each fragment can be independently identified during transmission, which is convenient for later reconstruction. This adaptive fragmentation adjustment mechanism enables the fragmentation size and number to be optimized according to actual network conditions such as bandwidth and delay, ensuring the transmission efficiency and reliability of each fragment. In addition, the introduction of the sequence number identifier and the first check code effectively reduces the error rate and out-of-order problem during the later reconstruction process.

[0105] After the receiving end receives the fragmented data in step S2, it first performs reconstruction analysis according to the original sequence number order, collects the arrival delay and sequence offset of each fragment, uses this information to construct a conflict analysis model, and calculates the fragment arrival order deviation amount Cpb, the overall conflict rate Ctz, and the timing consistency coefficient Tsj. When the overall conflict rate Ctz exceeds the preset conflict threshold, a first correction instruction is issued. When the timing consistency coefficient Tsj is lower than the stable threshold, a channel adjustment instruction and a second timing correction instruction are issued, and a data reconstruction analysis set is constructed; and the state of the transmission channel is optimized. This step effectively detects and diagnoses problems in data transmission by analyzing the arrival order and deviation amount of fragments in real time. Issuing conflict analysis and channel adjustment instructions in advance can respond to network congestion or transmission errors in a timely manner, avoid data loss and out-of-order, and improve the accuracy of data reconstruction.

[0106] When the system detects that multiple fragments are out of order or in conflict in S3, it will give priority to processing those unfrozen fragments and adjust the order according to the priority. This mechanism ensures that the order of the data can be correctly restored after all fragments are received, avoiding the reconstruction failure caused by out-of-order data. For the detected missing fragments, the system will generate retransmission instructions. The order preservation mechanism ensures that the order of the reconstructed data completely conforms to the original data order. Even in a complex and unstable network environment, the consistency and integrity of the data can be guaranteed. By dynamically adjusting the priority and timely retransmitting the missing fragments, the accurate restoration of the data is ensured.

[0107] During the recombination process, S4 dynamically adjusts the number of retransmissions Rcs, the retransmission interval Rtg, and performs sequential correction again after retransmission by combining the recombination analysis results and the safety margin factor a. This process continues until the recombined data stream is successfully restored. The adaptive retransmission mechanism automatically adjusts the retransmission strategy according to the network state and channel quality, effectively solving the problems of data loss or retransmission delay. The flexibility of the retransmission strategy greatly improves the reliability and orderliness of data transmission.

[0108] The adaptive data slice recombination and ordering method based on Beidou short messages of the present invention significantly improves the reliability and efficiency of data transmission in low-bandwidth and high-latency environments by introducing technical means such as adaptive fragmentation adjustment, recombination analysis, ordering mechanism, and adaptive retransmission. It not only solves the problems of data loss, out-of-order, and delay fluctuations that may occur in traditional slice transmission, but also ensures the sequential consistency and integrity of data, and is applicable to high-challenge environments such as satellite communication and low-orbit satellite communication, providing higher reliability guarantee for data transmission.

[0109] Embodiment 2

[0110] This embodiment is an explanatory description based on Embodiment 1. Specifically, S1 includes:

[0111] S11. Prepare the original data to be sent for fragmentation processing;

[0112] S12. Before data slicing, collect the channel quality parameters and bandwidth status parameters of the current channel in real time, and summarize them to form the first data set; it provides a comprehensive understanding of the current network condition, facilitating making optimization decisions before data slicing and ensuring the accuracy and reliability of data fragmentation. By dynamically adjusting the slice size and quantity, the data transmission efficiency can be effectively improved.

[0113] S12 specifically includes: S121. Directly measure the power of the channel signal by a power sensor to obtain the signal strength S; by monitoring the signal strength in real time, the situation of weak signals can be detected in a timely manner, and then the data fragmentation strategy can be optimized to avoid transmission errors caused by overly weak signals.

[0114] S122. Measure the actual usage of the current bandwidth by a network monitoring tool to obtain the real-time bandwidth utilization rate Br; the bandwidth utilization rate provides real-time feedback on the network load, which helps to adjust the fragmentation strategy. When the bandwidth is high, the slice size can be appropriately increased, and vice versa, to improve the transmission efficiency.

[0115] S123. Obtain the bit error rate Eb by statistically calculating the ratio of the number of error bits ccb to the total number of bits zbt at the receiving end:

[0116]

[0117] Real-time monitoring of the bit error rate can help determine the channel quality. If the bit error rate is high, the fragmentation size can be appropriately reduced or additional error checking can be performed to ensure the accurate transmission of data.

[0118] S124. Collect the noise power N in the noise detector, and combine it with the signal strength S to calculate and obtain the interference index J through the following formula:

[0119]

[0120] The interference index (J) can reflect the degree of interference of noise on the signal in the channel. If the interference index is high, appropriate measures can be taken, such as reducing the fragmentation size or increasing redundant data, to reduce the impact of interference on transmission.

[0121] The first data set includes the signal strength S, the bit error rate Eb, the interference index J, the maximum bandwidth Bmax, and the real-time bandwidth utilization rate Br.

[0122] S13. Within a fixed time window, the time window is set to 1 second; and within the time window, the signal strength S is sampled multiple times to obtain a set of signal strength data: S1, S2,..., S n , and calculate and obtain the signal strength mean S through the following formula:

[0123]

[0124] In the formula, S i represents the signal strength obtained in the i-th sampling time, and n represents the number of samplings; by sampling multiple times and calculating the mean, the fluctuation of the signal strength can be smoothed, reducing the influence of accidental factors on signal evaluation, and making the evaluation of the network status more accurate.

[0125] S14. Based on a set of signal strength data, calculate the signal strength variance through the following formula

[0126]

[0127] The signal strength variance reflects the stability of the signal. If the variance is large, it means that the signal fluctuates greatly, which may lead to unstable data transmission; on the contrary, if the variance is small, the signal is relatively stable.

[0128] S15. Combine the signal strength mean S and the signal strength variance Calculate and obtain the signal fluctuation coefficient σ through the following formula c :

[0129]

[0130] Among them, when the signal fluctuation coefficient σ cWhen the value is high, it indicates that the signal strength is unstable and fluctuates greatly; while when the signal fluctuation coefficient σ c is low, the signal is relatively stable. The signal fluctuation coefficient σ c provides a quantitative index for evaluating signal stability. When the signal fluctuation coefficient is high, the system can adopt a more conservative sharding strategy to ensure reliable data transmission in an unstable network.

[0131] S1 also includes: S16, extracting the bit error rate Eb, interference index J, and signal fluctuation coefficient σ c , after dimensionless processing, calculate the safety margin factor a through the following formula:

[0132] a = 1 + β * (σ c + J + Eb);

[0133] Among them, the adjustment coefficient β is used to adjust the sensitivity of the safety margin factor a, and its value range is 0.1 - 0.3; the safety margin factor a provides a comprehensive measurement standard, which can adjust the safety margin during data transmission to ensure that when the network quality is unstable, the system adopts a more secure transmission strategy.

[0134] S17, according to the channel and bandwidth status, calculate the optimal shard size Dsz through the following formula:

[0135]

[0136] Among them, J is the interference index, the higher it is, the smaller the shard size; Eb is the bit error rate, the higher it is, the smaller the shard size; T limit is the maximum allowed transmission time; by dynamically adjusting the shard size, the data transmission efficiency can be optimized according to the network conditions. In the case of strong signals and low interference, the shard size can be increased; conversely, it can be decreased to ensure transmission stability.

[0137] S18, collect the total size D of the data packets to be transmitted total , and according to the total size D of the data packets total and the optimal shard size Dsz, calculate and obtain the number of shards Nsz:

[0138]

[0139] By optimizing the number of shards, it can be ensured that the size of each shard is suitable for the current network conditions, thereby avoiding packet loss and errors during data transmission.

[0140] S19, add a unique serial number identifier to each shard for sorting during data recombination, and generate and append a first check code for each shard, including CRC check code;

[0141] Integrate the shard size, quantity, sequence number identifier, and the first checksum to form a complete shard data packet, and upload the preprocessed shard data sequentially through the channel interface of the Beidou satellite system for transmission.

[0142] Embodiment 3

[0143] This embodiment is an explanatory description based on Embodiment 1. Specifically, S2 includes:

[0144] S21. Continuously receive shard data from the Beidou short message system. Each received shard contains a unique sequence number identifier and the first checksum. The receiving end sorts the shards according to the sequence number identifier of each shard in a predetermined order to ensure that it can identify whether a shard is lost or arrives in order. Use the first checksum to detect the integrity of the shard and determine whether there are error codes. If an error code or data loss is detected, record the status of the shard and mark it as "lost" or "to be retransmitted"; if the shard sequence number identifiers are not continuous, consider the shard lost and record the number of lost shards L.

[0145] Ensure that the shards are received in order and completely through the sequence number identifier and the first checksum of each shard, avoiding data loss or errors. If an error code or loss occurs, the receiving end can record and mark the status in a timely manner to ensure the integrity and accuracy of the data.

[0146] S22. The timestamp T of each shard arriving at the receiving end i is recorded and used to calculate the arrival delay d of each shard i :

[0147] d i = T i - T send (i);

[0148] where T send (i) is the transmission time of shard i; by recording the arrival timestamp of each shard, calculate the arrival delay of each shard.

[0149] S23. According to each received shard, perform error code monitoring, sort the shard data according to the sequence number identifier, record the arrival time of each shard, calculate the arrival delay of each shard; record the sequence offset of each shard, that is, the difference between the actual arrival order and the ideal order, for analyzing the sequence offset situation, the arrival order deviation amount Cpb:

[0150]

[0151] In the formula, m represents the total number of shards received by the receiving end, O i is the actual arrival order of the i-th shard, E iis the ideal arrival order of the i-th shard; by calculating the order deviation of each shard (the difference between the actual arrival order and the ideal order), we can deeply analyze whether the shards arrive in the predetermined order and reveal the order disorder caused by delay. Combining the order deviation and loss status information of each shard, we can calculate the overall conflict rate Ctz, and then evaluate whether there is a serious conflict risk during data transmission.

[0152] S24. Based on the recorded arrival delay, sequence deviation and loss status information, calculate the overall conflict rate Ctz:

[0153]

[0154] Among them, Cpb i is the arrival order deviation of each shard, L i is the number of lost fragments detected in the i-th time, and m represents the total number of fragments received by the receiver.

[0155] S25. Analyze the time, location, and number of lost fragments of the conflict. Use the multi-layer perceptron MLP to build a conflict frequency distribution model and train it. Calculate the standard deviation of the arrival delay of all fragments and obtain the delay index Yczs:

[0156]

[0157] Where, d i represents the arrival delay time of the i-th fragment, d represents the average delay time of the fragment arrival, and m represents the total number of fragments received by the receiving end; the delay index Yczs is obtained by calculating the standard deviation of the arrival delay of all fragments. This delay index can be used as an indicator to measure the magnitude of delay fluctuations during data transmission. A smaller standard deviation means that the delay is more consistent and the data transmission is more stable; a larger standard deviation means that there is a larger delay fluctuation, which may cause data sorting difficulties or reorganization failures.

[0158] S26. According to the delay index Yczs, the timing consistency coefficient Tsj is calculated by the following formula:

[0159]

[0160] In the formula, δ max Indicates the maximum allowed delay. The timing consistency coefficient Tsj ranges from 0 to 1. The closer the value is to 1, the more consistent the arrival time of the shards is and the more stable the delay is. If Tsj is close to 0, it indicates that the delay fluctuates greatly, which may increase the difficulty of reorganizing the data sequence.

[0161] S27, preset a conflict threshold, and compare and analyze the conflict rate Ctz with the preset conflict threshold to obtain a first evaluation result, including:

[0162] When the overall conflict rate Ctz > the conflict threshold, it indicates that there is a serious conflict risk during the recombination process, and a first correction instruction is generated;

[0163] When the overall conflict rate Ctz ≤ the conflict threshold, it indicates that there is no serious conflict risk during the recombination process;

[0164] S28. Preset the stability threshold to 0.8, compare the timing consistency coefficient Tsj with the stability threshold to evaluate the time consistency of the overall data stream, and obtain a second evaluation result, including:

[0165] If the timing consistency coefficient Tsj > 0.8, it indicates that the shard transmission delay fluctuation is normal;

[0166] If the timing consistency coefficient Tsj ≤ 0.8, it indicates that the shard transmission delay fluctuation is abnormal, and a channel adjustment instruction and a second timing correction instruction are generated. The channel adjustment instruction includes: increasing the transmission power of the current signal by 20% - 30%, installing an anti-interference suppressor or a frequency hopping device, reducing the interference index J by 50% and increasing the bandwidth by 20% - 30%. The channel adjustment instruction guides the adjustment of the signal transmission power or frequency adjustment, etc., so as to reduce conflicts and improve the data transmission quality. Such as increasing the transmission power, installing anti-interference devices, reducing the interference index J, increasing the bandwidth, etc., to improve the stability of the channel. This dynamic correction mechanism helps the system to make self-adjustment in time when a large conflict occurs, ensuring the integrity and accuracy of the data.

[0167] In this embodiment, by combining the conflict rate, delay fluctuation and timing consistency coefficient, the system can comprehensively evaluate the current network condition, and give early warnings of potential risks, and take measures in advance to avoid data loss or recombination failure. This dynamic monitoring and evaluation mechanism enables the system to actively optimize during actual use, ensuring efficient communication and data transmission.

[0168] Embodiment 4

[0169] This embodiment is an explanatory description based on Embodiment 1. Specifically, S3 includes:

[0170] S31. After receiving the first correction instruction, count the number of lost shards L and the sequence deviation amount Cpb, classify the conflict types. If the sequence deviation is large, it is classified as a sequence conflict, and if there are lost shards, it is a loss conflict, and construct a data reorganization analysis set; the system organizes this data into a data reorganization analysis set to provide a decision basis for subsequent reorganization and correction. By classifying conflicts by type, different types of conflicts (such as sequence problems and loss problems) can be analyzed and processed more precisely, avoiding a one-size-fits-all approach. By constructing a reorganization analysis set, the system can more accurately identify and analyze conflicts, avoid unnecessary error handling, and thus improve the efficiency and accuracy of data reorganization.

[0171] S32. During the data reorganization analysis process, screen for high-deviation shards. When the sequence deviation amount Cpb exceeds the preset deviation threshold, the system marks this shard as "sequence abnormal" and records the serial number identifier of this shard; screening out high-deviation shards can concentrate resources to process these "problem" shards and avoid unnecessary processing. By accurately marking the shards with abnormal sequences, important shards can be avoided from being missed during subsequent reorganization, thereby improving the accuracy of data recovery.

[0172] S33. When receiving the second timing correction instruction, the system marks the shards in the time period when the timing consistency coefficient Ts ≤ 0.8 as: "timing inconsistent" and records the serial number identifiers of the shards in this time period;

[0173] During the process of the second timing correction instruction, the system checks the locking status of each shard and preferentially processes the shards in the "unlocked" state. These shards are not occupied by other operations and are convenient for preferential correction;

[0174] Sort the shards in the "unlocked" locking state, preferentially restore them to the correct order, and perform the first-priority correction in ascending order of the deviation amount Cpd; by preferentially correcting the unlocked shards, data can be recovered more efficiently because these shards can be adjusted immediately without waiting for other operations. By sorting in ascending order of the deviation amount Cpd, it can be ensured that the problems with the least impact on reorganization are solved first, avoiding the error propagation of large-deviation shards and ensuring the stability of the data.

[0175] S34. After the first-priority correction, sort the delay index Yczs in ascending order to obtain a second-priority correction list and perform the second-priority correction;

[0176] After the first-priority correction and the second-priority correction, the system forms a reorganized data stream in the corrected order; for the detected lost shards, the system generates a retransmission instruction.

[0177] In this embodiment, through the first-priority and second-priority corrections, the system ensures that data conflicts are gradually resolved, avoiding the complexity brought by one-time processing and improving the overall efficiency. By sorting based on the delay index, the system can prioritize the correction of those shards that have less impact on the timing consistency, thereby avoiding the processing of more difficult-to-correct shards and optimizing the recombination efficiency. For the lost shards, generating retransmission instructions helps to timely supplement the lost data and ensure the integrity of the final data. The system can dynamically adjust the correction strategy according to different conflict types, delays, and deviation situations, optimize the data recombination process, and ensure the high efficiency and stability of the system.

[0178] Embodiment 5

[0179] This embodiment is an explanatory description based on Embodiment 4. Specifically, the S4 step includes:

[0180] S41. Trigger the adaptive retransmission mechanism based on the retransmission instructions generated in the recombination analysis set constructed in the S3 step;

[0181] S42. Calculate and obtain the shard group interval factor G based on the number of shards Ccsl and density within the current retransmission group:

[0182]

[0183] In the formula, Ccsl is the number of shards within the current retransmission group, and T group is the average arrival time interval of the shards within the current retransmission group;

[0184] S43. The adaptive retransmission mechanism combines the safety margin factor a, bit error rate Eb, interference index J, and real-time bandwidth utilization Br in the S1 step. After dimensionless processing, calculate and obtain the retransmission times Rcs and retransmission interval Rtg through the following formula:

[0185]

[0186] The meaning of the formula is that the higher the real-time bandwidth utilization Br and signal strength S, the fewer the retransmission times can be; G represents the shard group interval factor.

[0187] S44. After retransmitting the shards according to the retransmission times Rcs and retransmission interval Rtg, perform another sequential correction on all the arrived shards based on the sequence number identifier. After repeating the S3 step, calibrate the position of the retransmitted shards in the recombined data stream;

[0188] S45. Verify the entire recombined data stream again. If the verification passes, confirm that the data recombination is completed; if the verification fails, repeat the S3 step to generate new retransmission instructions, re-trigger the adaptive retransmission mechanism, and go through the verification until the recombined data stream is successfully recombined.

[0189] In this embodiment, the retransmission instruction generated according to the foregoing analysis results ensures that the retransmission mechanism can adapt to dynamic conflict situations. This helps to ensure that the retransmission operation is not restricted by a fixed pattern and can flexibly respond to changes in network conditions, thereby improving the success rate of data recombination. By calculating the interval factor of the shard group, the system can evaluate and adjust the time interval of the retransmission operation, thereby avoiding overly dense or scattered retransmissions, reducing the risk of network congestion, and improving the utilization efficiency of the bandwidth. Based on the calculation of the shard group interval factor, the system can more precisely control the timing and interval of retransmissions, ensure that the timing of retransmissions is more appropriate, and help to improve the speed and success rate of data recovery. By introducing parameters such as bandwidth utilization rate, interference index, and bit error rate, the system can dynamically adjust the number and interval of retransmissions according to the current network conditions, thereby avoiding excessive retransmissions or excessive waiting, and ensuring the reasonable allocation of retransmission efficiency and network resources.

[0190] By adaptively adjusting the number and interval of retransmissions according to the changes in real-time bandwidth utilization rate and signal strength, the network burden can be reduced, network congestion can be avoided, and the reliability of data retransmission can be improved.

[0191] Retransmit the shards according to the calculated number of retransmissions (Rcs) and retransmission interval (Rtg).

[0192] After the retransmission is completed, the system reorders all the arrived shards according to the sequence number identifier of the shards to ensure that all shards are recombined in the correct order.

[0193] Repeat step S3 to calibrate the position of the retransmitted shards in the recombined data stream. By reordering the shards, the system can recover the misordered shards and avoid data recombination failure caused by order problems. Even if new order errors occur during the retransmission process, the system can still ensure the successful recombination of data by repeating the correction step, thereby improving the stability and integrity of the data stream.

[0194] By restarting the adaptive retransmission mechanism after each verification failure, the system can be optimized according to real-time feedback to ensure that the data can ultimately be completely recombined. Even in the case of recombination failure, the system can achieve automatic recovery through multiple rounds of retransmission and correction, improve the self-healing ability of the system, and reduce the need for manual intervention.

[0195] Embodiment 6

[0196] This embodiment is an explanatory description carried out in Embodiment 5. Specifically, the steps for verifying the entire recombined data stream in S45 are as follows:

[0197] S451. Check each received shard to verify its integrity and confirm whether there are any missing shards through the sequence number identifier; detecting missing shards using the sequence number identifier helps to promptly discover and handle missing shards, ensuring the smooth progress of subsequent data recombination processes.

[0198] S452. Check whether the sequence number identifiers of all shards have been correctly received and recombined, and after each retransmission, check whether the retransmitted data arrives on time and update the retransmission status during recombination; checking the on-time arrival of data after each retransmission can promptly update the status of shards, ensure the successful recovery of retransmitted shards, and avoid missed or duplicate retransmissions.

[0199] S453. Check whether there are any missing or unrecombinable shards.

[0200] For missing shards, trigger a new retransmission request, that is, return to step S31 for reanalysis and generation of a new retransmission instruction; if there are missing shards, record the sequence number identifiers of the missing shards and regenerate the retransmission instruction; by checking missing or unrecombinable shards and regenerating the retransmission instruction, the system can ensure that missing shards are promptly processed, increasing the success probability of data recombination. Automatically triggering a new retransmission request makes the handling of missing shards more efficient and automated, reducing manual intervention.

[0201] S454. Sort the received data using the sequence number identifiers of the shards and compare whether the order of the sorted data is consistent with the original sequence number order; sequence number sorting helps to eliminate order conflicts and improve the accuracy of data stream recombination, especially in complex shard transmission and retransmission processes.

[0202] S455. At the receiving end, verify the recombined data, generate a second checksum for each shard data, the second checksum includes CRC or hash value, and check whether the checksum of the shard data is consistent with the first checksum. If the second checksum is inconsistent, mark it as a verification failure and request retransmission of the shard; if the second checksum is inconsistent with the first checksum, the system can accurately mark the damaged or missing data, thus avoiding the propagation of incorrect data during retransmission.

[0203] S456. If there are any verification failures (such as verification failure, missing shards, etc.), generate a new retransmission instruction and re-trigger the adaptive retransmission mechanism, repeating the verification process of the above S451 - 455 steps until the recombination is successful.

[0204] In this embodiment, by re-triggering the adaptive retransmission mechanism and performing repeated verification, the system can continuously optimize the data reorganization process, ensure that each retransmission is more accurate, and effectively reduce the risk of retransmission failure. Through multiple rounds of verification steps, including serial number identifier confirmation, checksum verification, and sequence correction, the system can ensure the consistency and integrity of the data stream at each stage, avoiding reorganization errors. By utilizing the dynamic trigger retransmission mechanism, the system can automatically handle lost fragments, sequence problems, and checksum errors, reducing the need for manual intervention and improving transmission efficiency.

[0205] The threshold value is set for the convenience of comparison. Regarding the size of the threshold value, it depends on the amount of sample data and the base quantity set by those skilled in the art for each group of sample data; as long as it does not affect the proportional relationship between the parameter and the quantized value.

[0206] The above formulas are all obtained through software simulation by collecting a large amount of data and selecting a formula close to the true value. The coefficients in the formula are set by those skilled in the art according to the actual situation. The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and should be covered by the protection scope of the present invention.

Claims

1. Data slicing recombination and order preservation method based on Beidou short message, characterized in that Including the following steps: S1. Adaptive slicing adjustment: Before channel transmission, slice and fragment the original data to be sent, collect the current channel quality parameters and bandwidth status parameters, establish a first data set, construct a safety margin factor a, calculate and obtain the optimal slice size Dsz and the number of slices Nsz according to the margin factor a, and attach a unique sequence number identifier and a first check code to each slice through dynamically adjusted slice size and number, generate the original sequence number order, and upload the preprocessed sliced data to the Beidou satellite system; S2. Reorganization analysis: At the receiving end, receive the sliced data and perform reorganization analysis according to the original sequence number order, collect the arrival delay and slice order offset of each slice during the transmission process, construct a conflict analysis model based on this reorganization information, calculate the arrival order deviation amount Cpb, the overall conflict rate Ctz and the timing consistency coefficient Tsj of each slice reorganization. When the overall conflict rate Ctz exceeds the preset conflict threshold, issue a first correction instruction. When the timing consistency coefficient Tsj is lower than the stable threshold, issue a channel adjustment instruction and a second timing correction instruction, and construct a data reorganization analysis set; S3. Order preservation mechanism: Receive the second timing correction instruction, implement the order preservation mechanism, and perform data order correction using the arrival order deviation amount Cpb and the timing consistency coefficient Tsj; When there are conflicts or abnormal arrival orders for multiple slices, give priority to processing the slices whose data content is not locked, and adjust the order according to the priority to ensure that the reorganized data conforms to the original sequence order, forming a reorganized data stream. For the detected missing slices, the system generates a retransmission instruction; S4. Adaptive retransmission: Based on the retransmission instruction generated in the reorganization analysis set constructed in step S3, trigger the adaptive retransmission mechanism; The adaptive retransmission mechanism combines with the safety margin factor a, dynamically adjusts the number of retransmissions Rcs, the retransmission interval Rtg and performs another order correction after retransmitting the slices, and repeats steps S3 and S4 until the reorganized data stream is successfully reorganized.

2. The method for data slice recombination and order preservation based on Beidou short messages according to claim 1, wherein S1 includes: S11. Prepare the original data to be sent for slicing processing; S12. Before data slicing, collect the channel quality parameters and bandwidth status parameters of the current channel in real time, and summarize them to form a first data set; S12 specifically includes: S121. Directly measure the channel signal power magnitude by a power sensor to obtain the signal strength S; S122. Measure the actual bandwidth usage by a network monitoring tool to obtain the real-time bandwidth utilization rate Br; S123. Obtain the bit error rate Eb by statistically calculating the ratio of the number of error bits ccb to the total number of bits zbt at the receiving end; S124. Collect the noise power N in the noise detector, combine it with the signal strength S, and calculate and obtain the interference index J through the following formula: The first data set includes the signal strength S, the bit error rate Eb, the interference index J, the maximum bandwidth Bmax and the real-time bandwidth utilization rate Br.

3. The method for data slice recombination and order preservation based on Beidou short messages according to claim 2, wherein S1 also includes: S13. Within a fixed time window, the time window is set to 1 second; and within the time window, the signal strength S is sampled multiple times to obtain a set of signal strength data: S1, S2,..., S n , and the mean signal strength S is calculated and obtained through the following formula: Where S i represents the signal strength obtained at the i-th sampling time, and n represents the number of samplings; S14. Calculate the signal strength variance according to a set of signal strength data using the following formula S15. Combine the mean signal strength S and the signal strength variance Calculate and obtain the signal fluctuation coefficient σ through the following formula c : Among them, when the signal fluctuation coefficient σ c has a high value, it indicates that the signal strength is unstable and fluctuates greatly; while when the signal fluctuation coefficient σ c has a low value, the signal is relatively stable.

4. The method for data slice recombination and order preservation based on Beidou short messages according to claim 3, characterized in that, The S1 further includes: S16, extracting the bit error rate Eb, the interference index J, and the signal fluctuation coefficient σ c , after dimensionless processing, calculate the safety margin factor a through the following formula: a = 1 + β * (σ c + J + Eb); Among them, the adjustment coefficient β is used to adjust the sensitivity of the safety margin factor a, and its value range is 0.1 - 0.3; S17. According to the channel and bandwidth status, calculate the optimal slice size Dsz using the following formula: Among them, J is the interference index, and the higher it is, the smaller the fragment size; Eb is the bit error rate, and the higher it is, the smaller the fragment size; T limit is the maximum allowable transmission time; S18. Collect the total size D of the data packets to be transmitted total , and based on the total size D of the data packets total and the optimal fragmentation size Dsz, calculate and obtain the number of fragments Nsz: S19. Add a unique serial number identifier to each shard for sorting during data recombination, and generate and append a first check code for each shard, including a CRC check code. Integrate the shard size, quantity, serial number identifier, and first check code to form a complete shard data packet, and upload the preprocessed shard data sequentially through the channel interface of the Beidou satellite system for transmission.

5. The method for data slice recombination and order preservation based on Beidou short messages according to claim 1, characterized in that S2 It includes: S21. Continuously receive shard data from the Beidou short message system. Each received shard contains a unique serial number identifier and a first check code. The receiving end sorts the shards according to the serial number identifier of each shard in a predetermined order to ensure that it can identify whether a shard is lost or arrives in order. Use the first check code to detect the integrity of the shard and determine whether there are error codes. If an error code or data loss is detected, record the status of the shard and mark it as "lost" or "awaiting retransmission". If the shard serial number identifiers are not continuous, consider the shard lost and record the number of lost shards L. S22. The timestamp T of each shard arriving at the receiving end i is recorded and used to calculate the arrival delay d of each shard i : d i = T i - T send (i); Among them, T send (i) is the transmission time of slice i; S23. Perform error code monitoring based on each received shard, sort the shard data according to the serial number identifier, record the arrival time of each shard, and calculate the arrival delay of each shard. Record the sequence offset of each shard, that is, the difference between the actual arrival sequence and the ideal sequence, for analyzing the sequence offset situation, the arrival sequence deviation amount Cpb: where m represents the total number of shards received at the receiving end, O i is the actual arrival order of the i-th shard, and E i is the ideal arrival order of the i-th shard; S24. Calculate the overall conflict rate Ctz based on the recorded arrival delay, sequence deviation, and loss status information. Among them, Cpb i is the arrival order deviation amount of each shard, and L i is the number of shards lost in the i-th monitoring, and m represents the total number of shards received by the receiving end.

6. The method for data slice recombination and order preservation based on Beidou short messages according to claim 5, characterized in that S2 also includes: S25. Analyze the time, location, and number of lost shards when a conflict occurs. After constructing and training a conflict frequency distribution model using a multi-layer perceptron MLP, calculate the standard deviation of the arrival delays of all shards to obtain the delay index Yczs. where d i represents the arrival delay time of the i-th shard, represents the average arrival delay time of the shards, and m represents the total number of shards received by the receiver; S26. According to the delay index Yczs, calculate and obtain the timing consistency coefficient Tsj through the following formula: where δ max represents the maximum allowable delay. The time sequence consistency coefficient Tsj ranges from 0 to 1. The closer the value is to 1, the more consistent the arrival time of the shards is and the more stable the delay is. If Tsj is close to 0, it indicates that the delay fluctuation is large, which may increase the difficulty of reorganizing the data order; S27. Preset a conflict threshold, and compare and analyze the conflict rate Ctz with the preset conflict threshold to obtain a first evaluation result, including: When the overall conflict rate Ctz > the conflict threshold, it indicates that there is a serious conflict risk during the recombination process, and a first correction instruction is generated. When the overall conflict rate Ctz ≤ the conflict threshold, it indicates that there is no serious conflict risk during the recombination process. S28. Preset a stability threshold of 0.8, and compare the timing consistency coefficient Tsj with the stability threshold to evaluate the time consistency of the overall data stream, and obtain a second evaluation result, including: If the timing consistency coefficient Tsj > 0.8, it means that the shard transmission delay fluctuation is normal. If the timing consistency coefficient Tsj ≤ 0.8, it means that the shard transmission delay fluctuation is abnormal, and a channel adjustment instruction and a second timing correction instruction are generated. The channel adjustment instruction includes: increasing the transmission power of the current signal by 20% - 30%, installing an anti-interference suppressor or a frequency hopping device, reducing the interference index J by 50%, and increasing the bandwidth by 20% - 30%.

7. The method for data slice recombination and order preservation based on Beidou short message according to claim 6, wherein S3 It includes: S31. After receiving the first calibration instruction, count the number of lost shards L and the sequence deviation amount Cpb, classify the conflict types. If the sequence deviation is large, it is classified as a sequence conflict; if there are lost shards, it is a loss conflict, and construct a data recombination analysis set. S32. During the data recombination analysis process, filter out high-deviation shards. When the sequence deviation amount Cpb exceeds the preset deviation threshold, the system marks this shard as "sequence abnormal" and records the sequence number identifier of this shard. S33. When receiving the second timing calibration instruction, the system marks the shards in the time period when the timing consistency coefficient Ts ≤ 0.8 as: "timing inconsistent" and records the sequence number identifiers of the shards in this time period. During the process of the second timing calibration instruction, the system checks the locking status of each shard and preferentially processes the shards in the "unlocked" state. These shards are not occupied by other operations and are convenient for preferential calibration. Sort the shards in the "unlocked" locking state, and preferentially restore them to the correct order, and perform the first-priority calibration on the deviation amount Cpd from small to large. S34. After the first-priority calibration, sort the delay index Yczs from small to large to obtain the second-priority calibration list and perform the second-priority calibration. After the first-priority calibration and the second-priority calibration, the system forms a recombined data stream in the calibrated order; for the detected lost shards, the system generates a retransmission instruction.

8. The method for data slice recombination and order preservation based on Beidou short messages according to claim 7, wherein Step S4 includes: S41. Based on the retransmission instruction generated in the recombination analysis set constructed in step S3, trigger the adaptive retransmission mechanism. S42. Based on the number of shards Ccsl and the density in the current retransmission group, calculate and obtain the shard group interval factor G: Where Ccsl is the number of fragments in the current retransmission group, and T group is the average arrival time interval of the fragments in the current retransmission group; S43. The adaptive retransmission mechanism combines the safety margin factor a, the bit error rate Eb, the interference index J, and the real-time bandwidth utilization rate Br in step S1. After dimensionless processing, calculate and obtain the retransmission times Rcs and the retransmission interval Rtg through the following formula: The meaning of the formula is that the higher the real-time bandwidth utilization rate Br and the signal strength S, the fewer the retransmission times can be; G represents the shard group interval factor.

9. The method for data slice recombination and order preservation based on Beidou short messages according to claim 8, wherein Step S4 also includes: S44. After retransmitting the shards according to the retransmission times Rcs and the retransmission interval Rtg, perform another sequential calibration on all the arrived shards based on the sequence number identifier. After repeating step S3, calibrate the position of the retransmitted shards in the recombined data stream. S45. Verify the entire recombined data stream again. If the verification passes, confirm that the data recombination is completed; if the verification fails, repeat step S3 to generate a new retransmission instruction, re-trigger the adaptive retransmission mechanism, and go through the verification until the recombined data stream is successfully recombined.

10. The method for data slice reorganization and order preservation based on Beidou short messages according to claim 9, wherein The steps for verifying the entire recombined data stream again in S45 are: S451. Check each received shard to verify its integrity and confirm whether there are any lost shards through the sequence number identifier. S452. Check whether the sequence number identifiers of all shards have been correctly received and recombined, and after each retransmission, check whether the retransmitted data arrives on time and update the retransmission status during recombination. S453. Check whether there are any missing shards or inability to recombine; For the missing shards, trigger a new retransmission request, that is, go back to step S31 for re-analysis and generate a new retransmission instruction; if there are missing shards, record the serial number identifiers of the missing shards and regenerate the retransmission instruction; S454. Use the serial number identifiers of the shards to sort the received data, and compare whether the order of the sorted data is consistent with the order of the original serial number identifiers; S455. At the receiving end, perform verification on the recombined data, generate a second checksum for each shard data, the second checksum includes CRC or hash value, and check whether the checksum of the shard data is consistent with the first checksum. If the second checksum is inconsistent, mark it as verification failure and request retransmission of this shard; S456. If there are any verification failures, generate a new retransmission instruction and re-trigger the adaptive retransmission mechanism, repeat the verification process of the above S451-455 steps until successful recombination.

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