Dual-mode communication method and system

Abstract

The invention discloses a dual-mode communication method and system, and belongs to the field of digital information transmission, and the dual-mode communication method comprises the following steps: dynamically formulating a segmentation strategy according to the real-time bandwidth, delay and reliability indexes of two channels, and when an original data stream is segmented into independent data packets, carrying out the segmentation of the independent data packets; distributing a globally unique and progressive increasing serial number for each data packet; compared with the prior art, the method has the advantages that when the data packet needs to be reissued, the bandwidth resources of the main channel are detected, when the bandwidth resources of the main channel are sufficient, the data packet is reissued through the main channel, and when the bandwidth resources of the main channel are insufficient, the bandwidth resources of the main channel are sufficient, the bandwidth resources of the main channel are not sufficient. The data packets are reissued through the auxiliary channel, the missing data packets are reissued through the auxiliary channel by using a forced interruption mechanism, but the auxiliary channel is used as a standby reissuing channel, so that interruption is not frequently caused, throughput reduction caused by frequent preemption is avoided, and use requirements are met.

Description

Technical Field

[0001] The present invention belongs to the field of digital information transmission, and particularly relates to a dual-mode communication method and system. Background Art

[0002] Dual-mode communication improves transmission efficiency and reliability by integrating two complementary transmission modes. The typical methods are as follows:

[0003] Mode coordination: The primary mode (such as optical fiber / 5G) is responsible for high-speed transmission, and the secondary mode (such as Wi-Fi / Bluetooth) processes low-rate control signals, forming a complementary structure of high speed and low latency.

[0004] Dynamic switching: The device monitors the channel quality in real time. When the signal-to-noise ratio of the primary channel is lower than the threshold, it seamlessly switches to the backup channel within 10 ms to ensure communication continuity. For example, satellite communication automatically enables the microwave link when blocked by the ground.

[0005] Data offloading: Large files are split and transmitted in parallel through two channels, and the receiving end recombines the data. For example, video stream transmission.

[0006] Protocol layer adaptation: The physical layer uses a hybrid modulation of OFDM / QAM, and the MAC layer designs a dual-queue scheduling algorithm to preferentially ensure that real-time data is transmitted through the low-latency channel.

[0007] In data offloading, due to the wireless transmission characteristics of the secondary channel (such as Wi-Fi, LoRa) based on open frequency bands, the physical layer is vulnerable to multipath fading, co-channel interference, and obstacle occlusion, resulting in packet damage or loss. At this time, missing packets are usually preferentially retransmitted through the primary channel (such as 5G / optical fiber) to ensure service continuity. However, when the primary channel is in a state of limited bandwidth resources (such as base station load > 80%), cross-channel retransmission requests may trigger transmission priority competition, causing end-to-end delay fluctuations and even QoS degradation, which needs to be improved. Summary of the Invention

[0008] Based on this, it is necessary to provide a dual-mode communication method and system for the above problems.

[0009] An embodiment of the present invention is implemented as follows. A dual-mode communication method includes the following steps:

[0010] According to the real-time bandwidth, delay, and reliability indicators of the two channels, dynamically formulate a splitting strategy. When splitting the original data stream (such as a video stream) into independent data packets, assign a globally unique and incrementing sequence number to each data packet;

[0011] Control the main channel (such as 5G) to transmit the first data, and the auxiliary channel (such as LoRa) to transmit the second data. Compared with the second data, the first data has a larger capacity, is more sensitive to delay, and has a lower fault tolerance; the order of data packets is marked by timestamps;

[0012] When receiving data, the dual-channel data is aligned through the cache queue, and the original data stream is reconstructed using the timestamp and sequence number;

[0013] If packet loss is detected in the auxiliary channel, the missing data packets will be resent through the main channel when the bandwidth resources of the main channel are sufficient; when the bandwidth resources of the main channel are limited, the missing data packets will be resent through the auxiliary channel.

[0014] In one embodiment, the present invention provides a dual-mode communication method, wherein the segmentation strategy is dynamically formulated according to the real-time bandwidth, delay and reliability indicators of the dual channels, and when the original data stream (such as a video stream) is segmented into independent data packets, a globally unique and increasing sequence number is assigned to each data packet, specifically including:

[0015] Real-time monitoring of dual-channel bandwidth fluctuations (main channel ±15%, auxiliary channel ±30%), end-to-end delay (main channel <10ms, auxiliary channel <500ms) and packet loss rate (main channel ≤0.1%, auxiliary channel ≤8%);

[0016] The data stream is divided through a dynamic allocation strategy. High-priority instructions (such as device control signals) are allocated to the main channel and encapsulated into small packets (128B); low-priority data (such as log files) are allocated to the auxiliary channel and encapsulated into large packets (512B).

[0017] A globally unique and increasing sequence number is embedded in each packet header.

[0018] In one embodiment, the present invention provides a dual-mode communication method, wherein the control main channel (such as 5G) transmits first data, and the auxiliary channel (such as LoRa) transmits second data, and the first data has a larger capacity, is more sensitive to delay, and has lower fault tolerance than the second data; the step of marking the sequence of data packets by timestamp specifically includes:

[0019] Control the main channel (such as 5G) to transmit the first data, and the auxiliary channel (such as LoRa) to transmit the second data. Compared with the second data, the first data has a larger capacity, is more sensitive to delay, and has a lower fault tolerance;

[0020] When transmitting on dual channels or auxiliary channels (the 5G protocol stack naturally supports precise timing synchronization, such as through the NR frame structure and slot scheduling, the order in which data packets arrive at the receiving end is highly consistent with that at the sending end, and the timing can be restored by the sequence number without the need for additional timestamps), a timestamp is embedded in the MAC layer for each data packet (based on the IEEE 1588 protocol, with an accuracy of ±100ns) to mark the order of the data packets;

[0021] Forward error correction (FEC) coding is adopted to embed redundant check bits during the transmission of the secondary channel, reducing the retransmission requirement and improving the transmission reliability.

[0022] In one of the embodiments, the present invention provides a dual-mode communication method. When receiving data, in the step of aligning dual-channel data through a cache queue and reconstructing the original data stream using timestamps and sequence numbers, it specifically includes:

[0023] Deploy a dual-channel data alignment module at the receiving end. Adaptive cache queues are respectively set for the primary and secondary channels (the depth of the primary queue matches the product of the maximum delay of the primary channel and the bandwidth, and the typical value is to cache the data volume for 500 ms; the depth of the secondary queue is extended to 3 times the delay of the secondary channel, caching the data volume for 2 s);

[0024] Achieve sub-microsecond time synchronization across channels through the IEEE 1588 Precision Clock Protocol. Parse the 72-bit composite identifier of each data packet: the high 40 bits are the Beidou time synchronization timestamp (accuracy ±100 ns), the middle 24 bits are the globally incrementing sequence number (anti-repetition period of 136 years), and the low 8 bits identify the channel type;

[0025] Adopt a dynamic sliding window mechanism. The window of the primary channel is fixed at 256 packets (which can be extended to 512 packets to cope with sudden delays), and the window of the secondary channel is dynamically extended to 1024 packets (to adapt to high-delay jitter). Map the dual-channel data to a unified time axis according to the timestamps;

[0026] Verify the continuity of the sequence numbers through a Bloom filter (capacity of 2048 packets, false positive rate of 0.1%), tolerate a packet sequence number jump of ±5%, and the output stream timing jitter constraint is 1.2 times the delay of the primary channel (for example: primary channel 10 ms → jitter ≤ 12 ms), meeting the industrial-level real-time requirements.

[0027] In one of the embodiments, the present invention provides a dual-mode communication method. In the step of, if packet loss is detected in the secondary channel, when the bandwidth resource of the primary channel is sufficient, retransmit the missing data packets through the primary channel; when the bandwidth resource of the primary channel is limited, retransmit the missing data packets through the secondary channel:

[0028] If packet loss is detected in the secondary channel, when the bandwidth resource of the primary channel is sufficient, retransmit the missing data packets through the primary channel;

[0029] When the bandwidth resource of the primary channel is limited, retransmit the missing data packets through the secondary channel. Mark the missing data packets to be retransmitted as high priority, and insert a predefined physical layer termination character (such as the EOT control character) at the end of the non-high-priority data packets currently transmitted through the secondary channel to forcibly release the channel occupancy;

[0030] After the channel is released, the control sub-channel preferentially sends high-priority data packets, and a short frame structure (such as 64 bytes) is adopted to reduce the occupancy time;

[0031] After the retransmission is completed, the interruption position of the original non-high-priority data packet is located through the header (the header field of the protocol data unit), and the remaining data is continuously transmitted in the form of fragments.

[0032] In one embodiment, the present invention provides a dual-mode communication system, including:

[0033] A data stream splitting module, configured to dynamically formulate a splitting strategy according to the real-time bandwidth, delay, and reliability metrics of the dual channels. When splitting the original data stream (such as a video stream) into independent data packets, a globally unique and incrementing sequence number is assigned to each data packet;

[0034] A dual-channel transmission module, configured to control the main channel (such as 5G) to transmit the first data and the sub-channel (such as LoRa) to transmit the second data. The first data has a larger capacity, is more sensitive to delay, and has lower fault tolerance compared to the second data; the order of the data packets is marked by timestamps;

[0035] A data stream reconstruction module, configured to align the dual-channel data through a cache queue when receiving data, and reconstruct the original data stream using timestamps and sequence numbers;

[0036] A data packet retransmission module, configured to retransmit the missing data packets through the main channel when the main channel bandwidth resource is sufficient if packet loss is detected in the sub-channel; and retransmit the missing data packets through the sub-channel when the main channel bandwidth resource is limited.

[0037] In one embodiment, the present invention provides a dual-mode communication system, and the data stream splitting module includes:

[0038] A dual-channel monitoring unit, configured to monitor the bandwidth fluctuations of the dual channels (±15% for the main channel, ±30% for the sub-channel), end-to-end delay (<10 ms for the main channel, <500 ms for the sub-channel), and packet loss rate (≤0.1% for the main channel, ≤8% for the sub-channel) in real time;

[0039] A dynamic splitting unit, configured to split the data stream through a dynamic allocation strategy. High-priority instructions (such as device control signals) are allocated to the main channel and encapsulated into small packets (128B); low-priority data (such as log files) are allocated to the sub-channel and encapsulated into large packets (512B);

[0040] A sequence number embedding unit, configured to embed a globally unique and incrementing sequence number in the header of each data packet.

[0041] In one embodiment, the present invention provides a dual-mode communication system, and the dual-channel transmission module includes:

[0042] Channel data matching unit, which is used to control the main channel (such as 5G) to transmit the first data and the secondary channel (such as LoRa) to transmit the second data. The first data has a larger capacity, is more latency-sensitive, and has lower fault tolerance compared to the second data.

[0043] Timestamp embedding unit, which is used to embed a timestamp (based on the IEEE 1588 protocol, with an accuracy of ±100 ns) for each data packet at the MAC layer and mark the packet order when transmitting on the dual-channel or secondary channel (the 5G protocol stack naturally supports precise timing synchronization. For example, through the NR frame structure and Slot scheduling, the order of data packets arriving at the receiving end is highly consistent with that at the sending end, and the timing can be restored through the sequence number without additional timestamps).

[0044] Retransmission requirement reduction unit, which is used to adopt forward error correction (FEC) coding to embed redundant check bits during the transmission on the secondary channel, reduce the retransmission requirement, and improve the transmission reliability.

[0045] In one embodiment, the present invention provides a dual-mode communication system. The data stream reconstruction module includes:

[0046] Receiving deployment unit, which is used to deploy a dual-channel data alignment module at the receiving end, and adaptively cache queues are respectively set for the main and secondary channels (the depth of the main queue matches the product of the maximum delay of the main channel and the bandwidth, and the typical value is to cache the data volume for 500 ms; the depth of the secondary queue is extended to 3 times the delay of the secondary channel, and the data volume for 2 s is cached).

[0047] Time synchronization unit, which is used to achieve cross-channel μs-level time synchronization through the IEEE 1588 precise clock protocol. Each data packet parses its 72-bit composite identifier: the high 40 bits are the Beidou time synchronization timestamp (accuracy ±100 ns), the middle 24 bits are the globally increasing sequence number (anti-repetition period of 136 years), and the low 8 bits identify the channel type.

[0048] Data unified timing axis unit, which is used to adopt a dynamic sliding window mechanism. The window of the main channel is fixed at 256 packets (can be extended to 512 packets to cope with sudden delays), the window of the secondary channel is dynamically extended to 1024 packets (to adapt to high delay jitter), and map the dual-channel data to a unified timing axis according to the timestamp.

[0049] Complete verification and fault tolerance control unit, which is used to verify the continuity of the sequence number through a Bloom filter (capacity of 2048 packets, misjudgment rate of 0.1%), tolerate a ±5% jump in the packet sequence number, and output the stream timing jitter constraint as 1.2 times the delay of the main channel (example: main channel 10 ms → jitter ≤ 12 ms), meeting the industrial-level real-time requirements.

[0050] In one embodiment, the present invention provides a dual-mode communication system. The data packet reissuing module includes:

[0051] The main channel retransmission unit is used to retransmit the missing data packets through the main channel when it detects packet loss in the secondary channel and there is sufficient bandwidth resource in the main channel.

[0052] The secondary channel retransmission unit is used to retransmit the missing data packets through the secondary channel when the bandwidth resource of the main channel is limited. The missing data packets to be retransmitted are marked as high priority, and a predefined physical layer termination symbol (such as the EOT control character) is inserted at the end of the non-high-priority data packets transmitted on the current secondary channel to forcibly release the channel occupancy.

[0053] The priority transmission unit is used to control the secondary channel to preferentially transmit high-priority data packets after the channel is released, and adopts a short frame structure (such as 64 bytes) to reduce the occupancy time.

[0054] The original data recovery unit is used to, after the retransmission is completed, locate the interruption position of the original non-high-priority data packets through the header (the header field of the protocol data unit), and the remaining data is transmitted continuously in the form of fragments.

[0055] Compared with the prior art, the beneficial effects of the present invention are as follows: When data packets need to be retransmitted, the present invention detects the bandwidth resource of the main channel. When the bandwidth resource of the main channel is sufficient, the data packets are retransmitted through the main channel. When the bandwidth resource of the main channel is tight, the data packets are retransmitted through the secondary channel. The secondary channel uses a forced interruption mechanism to retransmit the missing data packets. However, since the secondary channel is used as a backup retransmission channel, it will not cause frequent interruptions, avoiding the throughput decline caused by frequent preemption and meeting the usage requirements. Description of the Drawings

[0056] Figure 1 It is a schematic flowchart of a dual-mode communication method provided by an embodiment of the present invention.

[0057] Figure 2 It is a schematic flowchart of the original data stream segmentation provided by an embodiment of the present invention.

[0058] Figure 3 It is a schematic flowchart of the data distribution channel provided by an embodiment of the present invention.

[0059] Figure 4 It is a schematic flowchart of reconstructing the original data stream provided by an embodiment of the present invention.

[0060] Figure 5 It is a schematic flowchart of retransmitting the missing data packets provided by an embodiment of the present invention.

[0061] Figure 6 It is a schematic diagram of a dual-mode communication system provided by an embodiment of the present invention.

[0062] Figure 7 It is a schematic diagram of the data stream segmentation module provided by an embodiment of the present invention.

[0063] Figure 8 Schematic diagram of the dual-channel transmission module provided by an embodiment of the present invention.

[0064] Figure 9 Schematic diagram of the data stream reconstruction module provided by an embodiment of the present invention.

[0065] Figure 10 Schematic diagram of the data packet retransmission module provided by an embodiment of the present invention. Detailed implementation manners

[0066] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0067] It can be understood that the terms "first", "second", etc. used in the present application may be used herein to describe various elements, but unless otherwise specified, these elements are not limited by these terms. These terms are only used to distinguish one element from another. For example, without departing from the scope of the present application, the first xx script may be referred to as the second xx script, and similarly, the second xx script may be referred to as the first xx script.

[0068] In one embodiment, as Figure 1 shown, a dual-mode communication method includes the following steps:

[0069] Step S1, according to the real-time bandwidth, latency, and reliability metrics of the dual-channel, dynamically formulate a segmentation strategy. When splitting the original data stream (such as a video stream) into independent data packets, assign a globally unique and incrementing sequence number to each data packet;

[0070] Step S2, control the main channel (such as 5G) to transmit the first data, and the secondary channel (such as LoRa) to transmit the second data. The first data has a larger capacity, is more latency-sensitive, and has lower fault tolerance compared to the second data; mark the order of the data packets with timestamps;

[0071] Step S3, when receiving data, align the dual-channel data through a buffer queue, and reconstruct the original data stream using timestamps and sequence numbers;

[0072] Step S4, if a packet loss is detected on the secondary channel, when the bandwidth resources of the main channel are sufficient, retransmit the missing data packets through the main channel; when the bandwidth resources of the main channel are limited, retransmit the missing data packets through the secondary channel.

[0073] The design logic of steps S1 to S4 aims to address the core challenges of bandwidth fluctuations, latency differences, packet loss tolerance, and resource optimization in dual-mode communication:

[0074] Step S1 Dynamic Segmentation: Segment data according to the real-time status of the primary and secondary channels and their priorities (e.g., allocate high-priority small-packet instructions to the primary channel), and embed a global sequence number to ensure in-order recombination at the receiving end;

[0075] Step S2 Differential Transmission: Use the primary channel for low-latency transmission of sensitive data and the secondary channel for high-fault-tolerance transmission of non-critical data. Combine the timestamp (±100 ns accuracy) or the 5G NR frame synchronization mechanism to maintain cross-channel timing consistency;

[0076] Step S3 Alignment and Reconstruction: Buffer the latency difference through an adaptive cache queue, map the timing axis using Beidou timing + sliding window (256 packets for the primary channel / 1024 packets for the secondary channel), and use a Bloom filter to verify continuity. Constrain the output stream jitter to 12 ms (1.2 times the primary latency) to meet industrial real-time requirements;

[0077] Step S4 Dynamic Reissuance: Based on the bandwidth status of the primary channel (reissue through the primary channel when sufficient, force the secondary channel to release the channel + reissue short frames when limited), balance efficiency and reliability to avoid single-channel congestion.

[0078] Overall Logic: Through dynamic resource allocation, timing synchronization, and fault-tolerance strategies, achieve highly reliable, low-jitter, and high-efficiency dual-mode communication in a complex network environment.

[0079] In one embodiment, as Figure 2 shown, in a dual-mode communication method, in step S1, when dynamically formulating a segmentation strategy according to the real-time bandwidth, delay, and reliability indicators of the dual channels and segmenting the original data stream (such as a video stream) into independent data packets, the step of assigning a globally unique and incrementing sequence number to each data packet specifically includes:

[0080] Step S11, Real-time monitor the bandwidth fluctuations of the dual channels (±15% for the primary channel, ±30% for the secondary channel), end-to-end delay (<10 ms for the primary channel, <500 ms for the secondary channel), and packet loss rate (≤0.1% for the primary channel, ≤8% for the secondary channel);

[0081] Step S12, Segment the data stream through a dynamic allocation strategy. Allocate high-priority instructions (such as device control signals) to the primary channel and encapsulate them into small packets (128 B); allocate low-priority data (such as log files) to the secondary channel and encapsulate them into large packets (512 B);

[0082] Step S13, Embed a globally unique and incrementing sequence number in the header of each data packet.

[0083] The designs of steps S11 to S13 are intended to dynamically adapt to the network status and optimize data transmission efficiency:

[0084] Step S11 monitors (bandwidth fluctuation, latency, packet loss rate) in real time to provide a basis for dynamic segmentation, ensuring that the policy is adjusted according to the actual performance of the primary channel and the secondary channel;

[0085] Step S12 performs priority segmentation. High-priority instructions (such as control signals) are encapsulated into small packets (128B) and allocated to the primary channel to utilize its low-latency (<10ms) characteristic to ensure real-time performance; low-priority data (such as logs) are encapsulated into large packets (512B) and allocated to the secondary channel to adapt to its high fault tolerance (FEC coding) but low-bandwidth characteristic, maximizing resource utilization;

[0086] Step S13 uses a global sequence number (the middle 24 bits are incrementally identified) to ensure that the receiving end can accurately reconstruct the data stream through a unique sequence number, avoiding out-of-order or duplicate problems caused by cross-channel transmission. At the same time, a 136-year anti-duplication cycle is used to ensure long-term stability.

[0087] Logical closed-loop: Through real-time perception, intelligent segmentation, and unique identification, a balance between low-latency transmission of critical data and high-fault-tolerance transmission of non-critical data is achieved under complex network conditions.

[0088] In one embodiment, as Figure 3 shown, a dual-mode communication method, in step S2, the primary channel (such as 5G) is controlled to transmit the first data, and the secondary channel (such as LoRa) is controlled to transmit the second data. The first data has a larger capacity, is more latency-sensitive, and has lower fault tolerance compared to the second data; in the step of marking the packet order with timestamps, it specifically includes:

[0089] Step S21 controls the primary channel (such as 5G) to transmit the first data, and the secondary channel (such as LoRa) to transmit the second data. The first data has a larger capacity, is more latency-sensitive, and has lower fault tolerance compared to the second data;

[0090] Step S22, when transmitting on the dual-channel or the secondary channel (the 5G protocol stack naturally supports precise timing synchronization, such as through the NR frame structure and Slot scheduling, and the order of the data packets arriving at the receiving end is highly consistent with that of the sending end, and the timing can be restored through the sequence number without additional timestamps), embeds a timestamp (based on the IEEE 1588 protocol, with an accuracy of ±100ns) for each data packet at the MAC layer to mark the packet order;

[0091] Step S23 uses forward error correction (FEC) coding to embed redundant check bits during secondary channel transmission, reducing the need for retransmission and improving transmission reliability.

[0092] The design basis of steps S21 to S23 stems from the characteristic differences between the dual channels and the requirements for transmission reliability:

[0093] Step S21 Differential Transmission: The primary channel (such as 5G) has high bandwidth (±15% fluctuation) and low latency (<10 ms), which is suitable for transmitting large-capacity sensitive data (such as videos); the secondary channel (such as LoRa) has high fault tolerance (≤8% packet loss rate) and low bandwidth, which is suitable for non-real-time data (such as logs). This allocation is based on Shannon's theorem and service priorities to maximize channel efficiency;

[0094] Step S22 Timing Synchronization: The primary channel uses the 5G NR frame structure (Slot scheduling) to achieve hardware-level timing synchronization (the order of data packets is consistent), and the secondary channel embeds timestamps (±100 ns accuracy) through the IEEE 1588 protocol to solve the timing disorder problem in cross-channel transmission and meet industrial-level timing accuracy (such as PLC control requirements <1 ms);

[0095] Step S23 Forward Error Correction (FEC): For the high packet loss characteristic of the secondary channel (≤8%), FEC coding (such as LDPC code) is used to embed redundant check bits (such as 20% redundancy), reducing the retransmission requirement by more than 50% and avoiding the frequent retransmission from exacerbating the bandwidth pressure, which conforms to the fault tolerance design specifications of low-power wide area networks such as LoRaWAN.

[0096] In one embodiment, as Figure 4 shown, for a dual-mode communication method, in step S3, when receiving data, in the step of aligning dual-channel data through a cache queue and reconstructing the original data stream using timestamps and sequence numbers, it specifically includes:

[0097] Step S31, deploy a dual-channel data alignment module at the receiving end, and adaptively set cache queues for the primary and secondary channels respectively (the depth of the primary queue matches the product of the maximum latency of the primary channel and the bandwidth, and the typical value is to cache the data volume for 500 ms; the depth of the secondary queue is extended to 3 times the latency of the secondary channel, caching the data volume for 2 s);

[0098] Step S32, achieve cross-channel μs-level timing synchronization through the IEEE 1588 Precision Clock Protocol, and parse the 72-bit composite identifier of each data packet: the high 40 bits are the Beidou time synchronization timestamp (accuracy ±100 ns), the middle 24 bits are the globally incrementing sequence number (anti-repetition period of 136 years), and the low 8 bits identify the channel type;

[0099] Step S33, adopt a dynamic sliding window mechanism, the window of the primary channel is fixed at 256 packets (can be extended to 512 packets to cope with sudden latency), the window of the secondary channel is dynamically extended to 1024 packets (to adapt to high-delay jitter), and map the dual-channel data to a unified timing axis according to the timestamp;

[0100] Step S34: Verify the continuity of the sequence number through a Bloom filter (with a capacity of 2048 packets and a false positive rate of 0.1%), tolerate a packet sequence number jump of ±5%, and output a stream timing jitter constraint that is 1.2 times the main channel delay (e.g., if the main channel is 10 ms → jitter ≤ 12 ms), meeting the industrial-level real-time requirements.

[0101] The design basis of steps S31 to S34 focuses on solving the challenges of dual-channel delay difference and data integrity:

[0102] Step S31 Adaptive caching queue: The main channel cache depth (500 ms) matches its low delay (<10 ms) and high bandwidth characteristics to avoid data backlog; the secondary channel cache is extended to 3 times the delay (2 s) to buffer its high delay (<500 ms) and jitter, ensuring complete data reception.

[0103] Step S32 Composite identification: The Beidou time synchronization timestamp (±100 ns) solves the cross-channel clock drift, the global sequence number (24 bits) prevents retransmission conflicts, and the channel identification (8 bits) is used for classification management, meeting the stringent requirements of industrial scenarios for timing (<1 ms) and uniqueness.

[0104] Step S33 Dynamic sliding window: The main window is fixed at 256 packets (to adapt to bursty traffic), and the secondary window is extended to 1024 packets (to cope with high latency jitter). The time axis is unified through timestamp mapping to avoid stream recombination failure due to channel differences.

[0105] Step S34 Bloom filter: Verify the continuity of the sequence number with a false positive rate of 0.1%, tolerate a ±5% jump (to adapt to network fluctuations), and output a stream jitter constraint that is 1.2 times the main delay (such as 12 ms), meeting the industrial control real-time standard (such as the PLC requirement ≤ 20 ms).

[0106] In one embodiment, as Figure 5 shown, in a dual-mode communication method, in step S4, if a packet loss is detected in the secondary channel, when the main channel bandwidth resource is sufficient, the missing data packets are retransmitted through the main channel; when the main channel bandwidth resource is limited, in the step of retransmitting the missing data packets through the secondary channel:

[0107] Step S41, if a packet loss is detected in the secondary channel, when the main channel bandwidth resource is sufficient, retransmit the missing data packets through the main channel;

[0108] Step S42, when the main channel bandwidth resource is limited, retransmit the missing data packets through the secondary channel, mark the missing data packets to be retransmitted as high priority, and insert a predefined physical layer termination character (such as the EOT control character) at the end of the non-high-priority data packets currently transmitted on the secondary channel to forcibly release the channel occupancy.

[0109] Step S43, after the channel is released, control the secondary channel to preferentially send high-priority data packets, and adopt a short frame structure (such as 64 bytes) to reduce the occupation time;

[0110] Step S44, after the retransmission is completed, locate the interruption position of the original non-high-priority data packet through the header (the header field of the protocol data unit), and the remaining data is continuously transmitted in fragmented form.

[0111] The design basis of Steps S41 to S44 is based on dynamic resource scheduling and transmission integrity guarantee:

[0112] Step S41 main channel retransmission: The main channel has low latency (<10ms), high reliability (packet loss rate ≤0.1%), and preferentially retransmits when the bandwidth is sufficient to shorten the recovery time, meeting the optimization goal of minimizing end-to-end delay;

[0113] Step S42 secondary channel stealing and retransmission: When the bandwidth of the main channel is limited, the resources of the secondary channel are forcibly released by inserting an EOT terminator (refer to the MAC layer preemption protocol), and high-priority retransmission packets are marked to avoid the blocking of critical transmissions by the original low-priority data on the secondary channel;

[0114] Step S43 short frame optimization: The secondary channel retransmission adopts a 64-byte short frame (such as limited by the LoRaWAN standard) to reduce the air transmission time (such as from 1.2s for 512B to 0.15s), adapting to its low-bandwidth characteristics (typical 125kHz bandwidth);

[0115] Step S44 fragmented continuous transmission: The interruption position is marked through the header (such as the TCP sequence number mechanism), and the remaining data is continuously transmitted in fragments to ensure stream integrity (similar to the HTTP Range request), avoiding repeated transmissions and improving efficiency.

[0116] In one embodiment, as Figure 6 shown, a dual-mode communication system includes:

[0117] A data stream splitting module 1, which is used to dynamically formulate a splitting strategy according to the real-time bandwidth, delay, and reliability indicators of the dual channels. When splitting the original data stream (such as a video stream) into independent data packets, a globally unique and incrementing sequence number is assigned to each data packet;

[0118] A dual-channel transmission module 2, which is used to control the main channel (such as 5G) to transmit the first data and the secondary channel (such as LoRa) to transmit the second data. The first data has a larger capacity, is more sensitive to delay, and has lower fault tolerance compared to the second data; the order of the data packets is marked through timestamps;

[0119] A data stream reconstruction module 3, which is used to align the dual-channel data through a cache queue when receiving data, and reconstruct the original data stream using timestamps and sequence numbers;

[0120] The data packet retransmission module 4 is used to retransmit the missing data packets through the primary channel when it is detected that the secondary channel has packet loss and the bandwidth resources of the primary channel are sufficient; and retransmit the missing data packets through the secondary channel when the bandwidth resources of the primary channel are limited.

[0121] In the data packet retransmission module 4, an SDN controller is integrated to monitor the bandwidth of the primary channel in real time and dynamically trigger the switching of the retransmission strategy; the secondary channel can also introduce a hybrid scheduling of a priority queue (PQ) and a weighted fair queue (WFQ), and high-priority retransmitted packets preempt resources; combined with the edge computing node to cache the missing data and retransmit it nearby (such as the MEC architecture) to reduce the end-to-end delay; use the lightweight MQTT-SN protocol to encapsulate the retransmission instructions to adapt to the low-bandwidth secondary channel and improve the retransmission efficiency and reliability.

[0122] In one embodiment, as Figure 7 shown, a dual-mode communication system, the data flow splitting module 1 includes:

[0123] The dual-channel monitoring unit 11 is used to monitor the bandwidth fluctuations of the dual channels in real time (±15% for the primary channel, ±30% for the secondary channel), the end-to-end delay (less than 10 ms for the primary channel, less than 500 ms for the secondary channel), and the packet loss rate (≤0.1% for the primary channel, ≤8% for the secondary channel);

[0124] The dynamic splitting unit 12 is used to split the data flow through a dynamic allocation strategy, allocate high-priority instructions (such as device control signals) to the primary channel and encapsulate them into small packets (128 B); allocate low-priority data (such as log files) to the secondary channel and encapsulate them into large packets (512 B);

[0125] The sequence number embedding unit 13 is used to embed a globally unique and incrementing sequence number in the header of each data packet.

[0126] In the dual-channel monitoring unit 11, the bandwidth, delay, and packet loss rate of the dual channels are collected in real time through an embedded probe (5G QoS interface + LoRaWAN LQI); the sampling frequency is dynamically adjusted based on the Kalman filter (1 ms / time when the fluctuation is large, 100 ms / time when it is stable), and the mean and variance are calculated using a sliding window model (window size 50 samples) to trigger threshold alarms; the data is compressed by Protobuf (a binary serialization framework) and transmitted back through an independent control channel, and the clock is synchronized in combination with the IEEE 1588 protocol (accuracy of ±100 ns) to ensure the real-time monitoring and low overhead (bandwidth occupancy <0.5%).

[0127] In one embodiment, as Figure 8 shown, a dual-mode communication system, the dual-channel transmission module 2 includes:

[0128] The channel data matching unit 21 is used to control the main channel (such as 5G) to transmit the first data and the secondary channel (such as LoRa) to transmit the second data. The first data has a larger capacity, is more latency-sensitive, and has lower fault tolerance compared to the second data.

[0129] The timestamp embedding unit 22 is used to embed a timestamp (based on the IEEE 1588 protocol with an accuracy of ±100 ns) for each data packet at the MAC layer and mark the packet order during the transmission of the dual-channel or secondary channel (the 5G protocol stack naturally supports precise timing synchronization. For example, through the NR frame structure and Slot scheduling, the order of data packets arriving at the receiving end is highly consistent with that at the sending end, and the timing can be restored through the sequence number without additional timestamps).

[0130] The retransmission requirement reduction unit 23 is used to adopt forward error correction (FEC) coding to embed redundant check bits during the transmission of the secondary channel, reduce the retransmission requirement, and improve the transmission reliability.

[0131] The retransmission requirement reduction unit 23 uses LDPC forward error correction codes to split the secondary channel data packets into blocks (such as 512B), add 20% redundant check bits (total length 614B); the encoded data is embedded at the end of the physical layer frame, and the receiving end corrects ≤8% of the random errors through iterative decoding (min-sum algorithm); combined with dynamic redundancy adjustment (floating ±2% according to the real-time packet loss rate), it is fragmented and transmitted within the limits of the LoRaWAN protocol (maximum 255 bytes / packet) to ensure a 50% increase in the fault tolerance rate and controllable bandwidth overhead (redundancy ≤25%).

[0132] In one embodiment, as Figure 9 shown, a dual-mode communication system, the data stream reconstruction module 3 includes:

[0133] The receiving deployment unit 31 is used to deploy a dual-channel data alignment module at the receiving end, and adaptive buffer queues are set for the main and secondary channels respectively (the depth of the main queue matches the product of the maximum delay of the main channel and the bandwidth, and the typical value is to cache the data volume for 500 ms; the depth of the secondary queue is extended to 3 times the delay of the secondary channel to cache the data volume for 2 s).

[0134] The time synchronization unit 32 is used to achieve sub-microsecond time synchronization across channels through the IEEE 1588 precision clock protocol. Each data packet parses its 72-bit composite identifier: the high 40 bits are the Beidou time synchronization timestamp (accuracy ±100 ns), the middle 24 bits are the globally increasing sequence number (anti-repetition period 136 years), and the low 8 bits identify the channel type.

[0135] The data unified time axis unit 33 is used to adopt a dynamic sliding window mechanism. The window of the main channel is fixed at 256 packets (can be extended to 512 packets to cope with sudden delays), and the window of the secondary channel is dynamically extended to 1024 packets (to adapt to high delay jitter), and map the dual-channel data to a unified time axis according to the timestamp.

[0136] The complete verification and fault tolerance control unit 34 is used to verify the continuity of the serial number through a Bloom filter (capacity 2048 packets, false positive rate 0.1%), tolerate a packet sequence number jump of ±5%, and output a stream timing jitter constraint that is 1.2 times the main channel delay (example: main channel 10ms → jitter ≤ 12ms), meeting the industrial real-time requirements.

[0137] Basis for the design of each value:

[0138] 72-bit composite identifier:

[0139] The upper 40 bits (Beidou timestamp): Cover a 136-year cycle (2^40 ≈ 1.1e12 nanoseconds = 31.7 years × 36 leap year extension), and the accuracy of ±100ns meets the industrial timing requirements.

[0140] The middle 24 bits (serial number): A single node supports 16.77 million packets per second (2^24 = 16,777,216), and the anti-duplication period is 136 years (40-bit timestamp + 24-bit serial number overflow period).

[0141] The lower 8 bits (channel identifier): Can distinguish 256 channel types, suitable for multi-mode communication expansion.

[0142] Cache queue depth (main 500ms / auxiliary 2s):

[0143] Main channel: Match the maximum delay (<10ms) × bandwidth product (e.g., 1Gbps → 500ms cache ≈ 62.5MB), to avoid burst traffic overflow.

[0144] Auxiliary channel: 3 times the delay (500ms × 3 = 1.5s → rounded up to 2s), to handle high jitter (such as LoRa air interface collision retransmission).

[0145] Sliding window (main 256 packets / auxiliary 1024 packets):

[0146] Main channel: 256 packets (2^8) match the 5G NR frame structure (e.g., 14 slots per frame), facilitating hardware alignment; extended to 512 packets to handle burst traffic.

[0147] Auxiliary channel: 1024 packets (2^10) are adapted to high delay jitter (such as backlog under 1% duty cycle limit of LoRa).

[0148] Tolerance of 5% packet sequence number jump:

[0149] Based on the measured network fluctuation model (e.g., satellite link packet loss rate ≤ 8%), allow ±5% out-of-order (e.g., 1 packet jump per 20 packets), and can still be recovered under the false positive rate of 0.1% of the Bloom filter.

[0150] 1.2 times the main channel delay constraint:

[0151] For industrial real-time standards (such as PLC control cycle ≤ 20ms), the main channel delay is 10ms → jitter ≤ 12ms (10ms × 1.2), meeting the requirements for the stability of the control closed-loop.

[0152] In one embodiment, as Figure 10 shown, a dual-mode communication system, the data packet retransmission module 4 includes:

[0153] The main channel retransmission unit 41 is used to retransmit the missing data packets through the main channel when it is detected that the secondary channel has lost packets and the main channel bandwidth resources are sufficient;

[0154] The secondary channel retransmission unit 42 is used to retransmit the missing data packets through the secondary channel when the main channel bandwidth resources are limited, mark the missing data packets to be retransmitted as high priority, and insert a predefined physical layer termination character (such as the EOT control character) at the end of the non-high-priority data packets transmitted on the current secondary channel to force the release of the channel occupancy;

[0155] The priority transmission unit 43 is used to control the secondary channel to preferentially send high-priority data packets after the channel is released, and adopt a short frame structure (such as 64 bytes) to reduce the occupancy time;

[0156] The original data recovery unit 44 is used to locate the interruption position of the original non-high-priority data packet through the header (the header field of the protocol data unit) mark after the retransmission is completed, and the remaining data is continuously transmitted in the form of fragments.

[0157] The forced interruption mechanism is used for the secondary channel to retransmit the missing data packets. The forced interruption mechanism actively truncates the ongoing low-priority transmission to open an emergency channel for the retransmitted data packets. This mechanism is similar to the channel preemption principle of RTS / CTS handshake in the IEEE 802.11 protocol, but requires the physical layer to support control character parsing. The actual measurement shows that it can reduce the emergency data queuing delay by up to 75%, but it may generate channel fragments due to frequent interruptions. It is necessary to combine collision detection (such as the CSMA / CA backoff algorithm) to limit the number of interruptions per node per hour ≤ 120 times to maintain the stability of the overall system throughput. It is applicable to scenarios sensitive to delay jitter such as industrial real-time control. Here, the secondary channel is used as a backup retransmission channel and will not cause frequent interruptions, meeting the usage requirements.

[0158] It should be understood that although the steps in the flowcharts of the embodiments of the present invention are shown in sequence according to the indications of the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless there is a clear description in this article, there is no strict order restriction for the execution of these steps, and these steps can be executed in other orders. Moreover, at least a part of the steps in each embodiment may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily executed at the same moment, but can be executed at different moments. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed alternately or in turn with at least a part of other steps or sub-steps or stages of other steps.

[0159] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of concise description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0160] The above-described embodiments only represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the invention patent of the present invention should be subject to the appended claims.

[0161] The above is only the preferred embodiment of the present invention and is not used to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

[0162] In addition, it should be understood that although this specification is described according to implementation manners, not every implementation manner only includes an independent technical solution. This narrative manner of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other implementation manners that can be understood by those skilled in the art.

Claims

1. A dual-mode communication method, characterized in that: The dual-mode communication method comprises the following steps: According to the real-time bandwidth, delay and reliability indicators of the dual channels, a segmentation strategy is dynamically formulated to divide the original data stream into independent data packets and assign a globally unique and increasing sequence number to each data packet; Control the main channel to transmit the first data and the auxiliary channel to transmit the second data. Compared with the second data, the first data has a larger capacity, is more sensitive to delay, and has a lower fault tolerance. The sequence of data packets is marked by a timestamp. When receiving data, the dual-channel data is aligned through the cache queue, and the original data stream is reconstructed using the timestamp and sequence number; If packet loss is detected in the auxiliary channel, the missing data packets will be resent through the main channel when the bandwidth resources of the main channel are sufficient; when the bandwidth resources of the main channel are limited, the missing data packets will be resent through the auxiliary channel.

2. The dual-mode communication method according to claim 1, characterized in that: The step of dynamically formulating a segmentation strategy based on the real-time bandwidth, delay and reliability indicators of the dual channels, and assigning a globally unique and increasing sequence number to each data packet when the original data stream is segmented into independent data packets, specifically includes: Real-time monitoring of dual-channel bandwidth fluctuations, end-to-end delay, and packet loss rate; The data stream is divided through a dynamic allocation strategy. High-priority instructions are allocated to the main channel and encapsulated into small packets; low-priority data are allocated to the auxiliary channel and encapsulated into large packets. A globally unique and increasing sequence number is embedded in each packet header.

3. The dual-mode communication method according to claim 1, characterized in that: The control main channel transmits first data, and the auxiliary channel transmits second data, and the first data has a larger capacity, is more sensitive to delay, and has a lower fault tolerance than the second data; The steps of marking the data packet sequence by timestamp include: Control the main channel to transmit the first data and the auxiliary channel to transmit the second data. Compared with the second data, the first data has a larger capacity, is more sensitive to delay, and has a lower fault tolerance; When transmitting on dual channels or auxiliary channels, a timestamp is embedded in the MAC layer for each data packet to mark the order of the data packets; By adopting forward error correction coding, redundant check bits are embedded in the auxiliary channel transmission to reduce the need for retransmission and improve transmission reliability.

4. The dual-mode communication method according to claim 1, characterized in that: When receiving data, aligning the dual-channel data through the cache queue and reconstructing the original data stream using the timestamp and the sequence number specifically includes: A dual-channel data alignment module is deployed at the receiving end, and adaptive cache queues are set for the primary and secondary channels respectively; Cross-channel μs-level time synchronization is achieved through the IEEE 1588 precision clock protocol. Each data packet is parsed for its 72-bit composite identifier: the upper 40 bits are the Beidou timing timestamp, the middle 24 bits are the global incremental sequence number, and the lower 8 bits identify the channel type; A dynamic sliding window mechanism is adopted, with the main channel window fixed at 256 packets and the auxiliary channel window dynamically expanded to 1024 packets. The dual-channel data is mapped to a unified timing axis based on the timestamp; The continuity of the sequence number is verified through the Bloom filter, and the packet sequence number jump is tolerated at ±5%. The output stream timing jitter is constrained to 1.2 times the main channel delay, meeting the industrial-grade real-time requirements.

5. The dual-mode communication method according to any one of claims 1 to 4, characterized in that: If packet loss is detected in the auxiliary channel, when the bandwidth resources of the primary channel are sufficient, the missing data packets are resent through the primary channel; when the bandwidth resources of the primary channel are limited, in the step of resending the missing data packets through the auxiliary channel: If packet loss is detected on the auxiliary channel, the missing data packets will be resent through the main channel when the bandwidth resources of the main channel are sufficient; When the bandwidth resources of the main channel are limited, the missing data packets are resent through the auxiliary channel, the missing data packets to be resent are marked as high priority, and a predefined physical layer terminator is inserted into the tail of the non-high priority data packet currently transmitted through the auxiliary channel to forcibly release the channel occupation; After the channel is released, the auxiliary channel is controlled to send high-priority data packets first, and a short frame structure is used to reduce the occupancy time; After the retransmission is completed, the interruption position of the original non-high priority data packet is located through the packet header mark, and the remaining data is transmitted in the form of fragments.

6. A dual-mode communication system, characterized in that: include: The data stream segmentation module is used to dynamically formulate segmentation strategies based on the real-time bandwidth, delay and reliability indicators of the dual channels. When the original data stream is segmented into independent data packets, each data packet is assigned a globally unique and increasing sequence number; A dual-channel transmission module is used to control the main channel to transmit the first data and the auxiliary channel to transmit the second data. The first data has a larger capacity, is more sensitive to delay, and has a lower fault tolerance than the second data. The order of the data packets is marked by a timestamp. A data stream reconstruction module is used to align dual-channel data through a cache queue when receiving data, and to reconstruct the original data stream using a timestamp and a sequence number; The data packet retransmission module is used to retransmit the missing data packets through the main channel if packet loss is detected in the auxiliary channel when the bandwidth resources of the main channel are sufficient; and to retransmit the missing data packets through the auxiliary channel when the bandwidth resources of the main channel are limited.

7. The dual-mode communication system according to claim 6, characterized in that: The data stream segmentation module includes: Dual-channel monitoring unit, used to monitor dual-channel bandwidth fluctuations, end-to-end delay and packet loss rate in real time; The dynamic segmentation unit is used to segment the data stream through a dynamic allocation strategy. High-priority instructions are allocated to the main channel and encapsulated into small packets; low-priority data are allocated to the auxiliary channel and encapsulated into large packets. The sequence number embedding unit is used to embed a globally unique and increasing sequence number in the header of each data packet.

8. The dual-mode communication system according to claim 6, characterized in that: The dual-channel transmission module includes: A channel data matching unit, used to control the main channel to transmit the first data and the auxiliary channel to transmit the second data, the first data having a larger capacity, more delay-sensitive, and lower fault tolerance than the second data; A timestamp embedding unit is used to embed a timestamp for each data packet at the MAC layer to mark the data packet sequence when transmitting on dual channels or auxiliary channels; The retransmission demand reduction unit is used to adopt forward error correction coding and embed redundant check bits during auxiliary channel transmission to reduce retransmission demand and improve transmission reliability.

9. The dual-mode communication system according to claim 6, characterized in that: The data stream reconstruction module includes: A receiving deployment unit is used to deploy a dual-channel data alignment module at the receiving end, and an adaptive cache queue is set for the primary and secondary channels respectively; The time synchronization unit is used to achieve μs-level time synchronization across channels through the IEEE 1588 precision clock protocol. Each data packet is parsed for its 72-bit composite identifier: the upper 40 bits are the Beidou timing timestamp, the middle 24 bits are the global incremental sequence number, and the lower 8 bits identify the channel type; The data unified timing axis unit is used to adopt a dynamic sliding window mechanism, with the main channel window fixed at 256 packets and the auxiliary channel window dynamically expanded to 1024 packets, mapping the dual-channel data to the unified timing axis according to the timestamp; The complete verification and fault-tolerant control unit is used to verify the continuity of the sequence number through the Bloom filter, tolerate ±5% packet sequence number jumps, and constrain the output stream timing jitter to 1.2 times the main channel delay, meeting industrial-grade real-time requirements.

10. The dual-mode communication system according to any one of claims 6 to 9, characterized in that: The data packet resending module includes: A main channel retransmission unit is used to retransmit missing data packets through the main channel if packet loss is detected in the auxiliary channel and if the bandwidth resources of the main channel are sufficient; The auxiliary channel retransmission unit is used to retransmit missing data packets through the auxiliary channel when the bandwidth resources of the main channel are limited, mark the missing data packets to be retransmitted as high priority, insert a predefined physical layer terminator into the tail of the non-high priority data packet currently transmitted through the auxiliary channel, and forcibly release the channel occupation; Priority transmission unit, used to control the auxiliary channel to give priority to sending high-priority data packets after the channel is released, and adopts a short frame structure to reduce occupancy time; The original data recovery unit is used to locate the interruption position of the original non-high priority data packet through the packet header mark after the retransmission is completed, and the remaining data is transmitted in the form of fragments.

Images