A Dynamic Routing Control System for Self-Organizing Networks Based on SDR

Abstract

This invention relates to the field of ad hoc network digital information transmission technology, and discloses an SDR-based ad hoc network dynamic routing control system, comprising: an SDR physical layer trend sensing unit that generates a feedforward signal through mean and variance collaborative arbitration; this signal triggers a data plane feedforward switching unit to enter switching standby mode, and triggers an SDR physical layer transmitter to transmit micro-disturbance probe packets to the backup route; the data plane feedforward switching unit is limited to performing redirection only when it receives the physical layer echo of the probe packet. This invention utilizes the mean and variance collaborative arbitration mechanism to avoid false alarms while actively detecting micro-disturbances to verify the physical layer freshness of the backup route before switching, thus solving the problem of invalid switching caused by lag in routing information.

Description

Technical Field

[0001] This invention relates to an SDR-based dynamic routing control system for self-organizing networks, belonging to the field of digital information transmission technology for self-organizing networks. Background Technology

[0002] Currently, especially in mobile ad hoc networks, dynamic routing protocols based on distance vectors or link states maintain effective digital information transmission paths in dynamically changing topologies. However, in highly dynamic application scenarios such as vehicular networks or drone networks, routing protocols typically employ a passive response logic: when a physical link is interrupted, the routing protocol detects the interruption through mechanisms such as timed packet timeouts and initiates a route reconvergence process. Before a new effective path is established after reconvergence, there is a transmission interruption period where no effective path exists. During this interruption period, digital information packets are either continuously sent to the failed path and lost in large quantities, or transmission stops due to the lack of effective routes. The application of Software-Defined Radio (SDR) technology provides physical layer awareness capabilities for such networks. Existing solutions utilize this awareness information to trigger or accelerate the aforementioned reconvergence process, but this does not change the routing protocol's interruption-then-response operating mechanism. The transmission interruption problem caused by control plane reconvergence delay remains unresolved.

[0003] Against this backdrop, existing solutions address rapid topology changes by optimizing the routing protocols themselves in the control plane, rather than utilizing physical layer awareness. For example, Chinese invention patent CN110972209B discloses a dynamic control method for the propagation range of routing protocols in wireless ad hoc networks. This scheme limits the propagation range of routing protocol information by defining a limited transmission area through hop count, reducing control plane overhead and adapting to topology changes. However, this method is essentially an optimization of the control plane. While it reduces the proliferation of routing information, it does not solve the fundamental problem of interruption followed by response. When a link on the selected path fails, passive reconvergence still relies on the limited routing protocol. In highly dynamic scenarios, this convergence delay still exists, and the forwarding continuity of the data plane is still constrained by the response speed of the control plane. The problem of transmission interruption has not been fundamentally solved.

[0004] Therefore, the technical problem to be solved by this invention is how to provide a dynamic routing control system that can shift from passive response to active avoidance, switch data streams before physical link failure, separate the fast forwarding of the data plane from the slow convergence of the control plane, and avoid the impact of transmission interruption on the continuity of digital information transmission. Summary of the Invention

[0005] To address the problems mentioned in the background art, the technical solution of the present invention is as follows: A dynamic routing control system for self-organizing networks based on SDR, the system comprising:

[0006] SDR physical layer trend sensing unit;

[0007] The route bypass caching unit, based on the topology information of the main routing protocol, pre-calculates and caches backup routes for the primary routes corresponding to the primary physical links carrying digital information transmission.

[0008] SDR physical layer transmitter;

[0009] SDR physical layer receiver and data plane feedforward switching unit;

[0010] The SDR physical layer trend sensing unit is used to calculate the mean trend and variance of the link quality parameters of the primary physical link in the timing sliding window queue in parallel. The SDR physical layer trend sensing unit is limited to generating a feedforward signal that the primary link is about to fail when the mean trend exceeds the preset feedforward trigger threshold and the variance is lower than the preset stability threshold.

[0011] The SDR physical layer trend sensing unit, when generating the feedforward signal, is also used to: send the feedforward signal to the data plane feedforward switching unit to trigger the data plane feedforward switching unit to enter the switching standby state; and send the feedforward signal to the SDR physical layer transmitter to trigger the SDR physical layer transmitter to actively transmit SDR physical layer micro-disturbance detection packets to the first hop node of the backup route cached by the route bypass cache unit.

[0012] The data plane feedforward switching unit operates under the following rules: only when the SDR physical layer receiver successfully receives the physical layer echo of the SDR physical layer perturbation detection packet within the preset perturbation timeout threshold will the switching standby state be released and the forwarding operation of redirecting digital information transmission to the backup route be performed.

[0013] Preferably, the data plane feedforward switching unit is also used to notify the primary routing protocol of the primary route failure after performing the forwarding operation, thereby triggering the route reconvergence of the primary routing protocol.

[0014] Preferably, the SDR physical layer trend sensing unit is also used to monitor the physical layer synchronization status of the primary physical link, and when the SDR physical layer trend sensing unit detects that the physical layer synchronization status is momentarily lost, it immediately generates a feedforward signal that the primary link is about to fail.

[0015] Preferably, the backup routes pre-calculated by the route bypass cache unit do not intersect with the primary routes in terms of topology.

[0016] Preferably, the SDR physical layer trend sensing unit is also used to obtain the physical link quality information of the backup routes cached in the route bypass caching unit by passively monitoring the background control traffic in the network; the route bypass caching unit is also used to perform physical layer trust verification on the backup routes based on the physical link quality information fed back by the SDR physical layer trend sensing unit; the SDR physical layer transmitter is limited to the first hop node of the backup routes that have passed the physical layer trust verification, and transmits SDR physical layer micro-perturbation probe packets.

[0017] Preferably, the SDR physical layer trend sensing unit calculates a quantified expected failure time based on the mean trend. Output expected failure time The route bypass cache unit obtains the expected update time of the main routing protocol. The data plane feedforward switching unit is also used to obtain the expected failure time. Compared to the expected update time The data plane feedforward switching unit is limited to the expected failure time. Less than expected update time Only when the time is right will the feedforward signal be responded to.

[0018] Preferably, the SDR physical layer trend sensing unit realizes the mean trend by performing first-order difference calculation or linear regression slope calculation on the time-series sliding window queue of link quality parameters.

[0019] Preferably, the route bypass caching unit is also used to obtain the congestion metric generated by the main routing protocol to characterize the link congestion degree; when pre-calculating and caching backup routes, the route bypass caching unit is limited to selecting routes with congestion degrees lower than a preset congestion threshold from multiple candidate backup routes based on the congestion metric, as backup routes.

[0020] Preferably, the data plane feedforward switching unit operates under the following rules: when the SDR physical layer receiver does not receive a physical layer echo within a preset micro-disturbance timeout threshold, it actively abandons the forwarding operation and triggers the routing bypass buffer unit to clear or rebuild its buffer.

[0021] Preferably, the link quality parameters include signal-to-noise ratio (SNR) or channel quality indicator (CQI).

[0022] Compared with the prior art, the beneficial effects of the present invention are:

[0023] 1. In ad hoc network dynamic routing control, the SDR physical layer trend sensing unit analyzes the link quality deterioration trend and generates a feedforward signal before the primary physical link is actually interrupted. This signal does not trigger the reconvergence of the primary routing protocol, but instead prioritizes driving the data plane feedforward switching unit to obtain the pre-calculated backup route from the route bypass cache unit and seamlessly redirects the digital information transmission to the backup route. Only after the data flow switching is completed does the switching unit notify the primary routing protocol of the failure. This architecture of switching the data plane first and then notifying the control plane separates the continuity of digital information transmission from the inherent slow convergence process of the routing protocol control plane. By using the active method of data plane bypass, the decision vacuum period inevitably caused by the inertia of the control plane is avoided in the passive method of routing protocol responding after interruption, thus ensuring low packet loss rate and continuity of digital information transmission in a highly dynamic environment.

[0024] 2. By coordinating the route bypass caching unit and the SDR physical layer trend sensing unit, the technical problem of inconsistency between logical topology and physical reality is solved. When the caching unit calculates backup routes in the background, the sensing unit uses its passive listening capability to conduct a background check on the physical layer health of the first hop of the backup routes in the cache. When the backup route passes this physical layer trust verification, the data plane feedforward switching unit is allowed to call the path when it receives the feedforward signal. This mechanism ensures that the backup route pointed to by each feedforward switch is an effective path selected based on real-time physical sensing rather than lagging topology information without increasing additional detection overhead, thus avoiding the digital information flow from switching from a path that is about to fail to an equally ineffective path.

[0025] 3. The SDR physical layer trend sensing unit has a high-precision trigger arbitration mechanism that can effectively distinguish between real attenuation and instantaneous noise. When monitoring link quality, this unit calculates the mean trend and variance of the timing sliding window queue. The internal logic is limited to generating a feedforward signal only when the mean trend continues to deteriorate and the variance remains stable at a low level. This mean-variance collaborative arbitration suppresses false alarms caused by the decrease in mean due to instantaneous noise interference and avoids jitter caused by unnecessary path switching to digital information transmission. This unit also monitors the physical layer synchronization status and triggers when synchronization is lost. This gradual and instantaneous dual-modal monitoring ensures that the system can achieve proactive and rapid route switching under different failure modes. Attached Figure Description

[0026] Figure 1 This is a flowchart illustrating the feedforward switching and active verification process of the system of the present invention.

[0027] Figure 2 This is a diagram showing the core functional logic and entity interaction relationships of the system of this invention;

[0028] Figure 3This is a diagram showing the deployment architecture of the dynamic routing control system of the present invention on the SDR node. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be further described in detail below. It should be understood that the specific embodiments described herein are only used to explain this invention and are not intended to limit the scope of protection of this invention.

[0030] This invention provides a dynamic routing control system for ad hoc networks based on SDR (Self-Organizing Network). The system is deployed on SDR nodes in the ad hoc network and is used to construct a control architecture that separates physical layer awareness, data plane forwarding, and control plane convergence. Logically, it mainly includes an SDR physical layer trend awareness unit, a route bypass caching unit, a data plane feedforward switching unit, and SDR physical layer transmitters and receivers. The SDR physical layer trend awareness unit predicts the failure trend of the primary physical link and generates feedforward signals. The route bypass caching unit pre-calculates and maintains backup routes. The data plane feedforward switching unit responds to the feedforward signals. After the SDR physical layer transmitter and receiver collaboratively complete the active verification of the freshness of the backup routes, it performs a forwarding operation to redirect digital information transmission to the backup routes. Before the primary routing protocol detects failure and reconvenes, it completes the active avoidance of data plane failure. The route bypass caching unit solves the problem of digital information transmission in ad hoc network nodes. The main routing protocol control plane convergence is slow, leading to transmission interruptions. This unit, acting as a background observer process for the main routing protocol, such as OLSR or AODV, passively reads the topology information maintained by the main routing protocol. Based on this topology information, it pre-calculates one or more backup routes and caches them for the primary route corresponding to the primary physical link currently carrying digital information transmission. In a preferred implementation, the backup routes do not intersect with the primary routes in terms of topology, avoiding the risk of shared link or node failures. To avoid switching data flows to congested paths, the route bypass caching unit obtains a congestion metric generated by the main routing protocol to characterize link congestion when calculating backup routes. This metric can be calculated based on queue length or transmission delay. Routes with congestion levels below a preset congestion threshold are selected as the final cached backup routes. This congestion threshold can be calibrated according to the QoS requirements of the network service; in a specific example, it is set to 70% of the maximum link capacity.

[0031] The SDR physical layer trend sensing unit addresses the issues of false alarms caused by instantaneous fluctuations in link quality and untimely responses to instantaneous link failures in digital information transmission. This unit continuously monitors the link quality parameters of the primary physical link carrying digital information transmission. These parameters can be signal-to-noise ratio (SNR) or channel quality indicator (CQI). The unit maintains a time-series sliding window queue for the link quality parameters and calculates the mean trend and variance of the data in the queue in parallel. The mean trend is used to quantify the rate of link quality degradation by performing first-order difference calculations or linear... The regression slope is calculated to achieve this, while variance characterizes the volatility of link quality. The triggering logic of this SDR physical layer trend sensing unit is limited to generating a feedforward signal that the primary link is about to fail when the mean trend continues to deteriorate beyond a preset feedforward trigger threshold and the variance is lower than a preset stability threshold. This mean-variance collaborative arbitration mechanism utilizes the low variance and negative trend statistical fingerprint unique to true attenuation to avoid false alarms caused by high variance and negative trend due to instantaneous noise. To cope with sudden interruptions, the SDR physical layer trend sensing unit monitors the primary physical link. The physical layer synchronization state is monitored, and when a loss of physical layer synchronization state is detected, indicating a sudden hard interruption, a feedforward signal indicating that the primary link is about to fail is generated, forming a dual-mode failure monitoring. The SDR physical layer trend sensing unit sets a fixed queue length N for the timing sliding window queue. The value of N can be calibrated according to the sampling rate of the link quality parameters and the expected failure prediction time window. In a system with a sampling rate of 100 times / second, in order to obtain the trend based on the previous 2 seconds, the value of N can be set to 200. In the specific implementation of the unit, in order to reduce the execution speed on the SDR embedded processor... The real-time computational load of linear regression slope calculation is limited to a low-complexity implementation method for mean trend calculation. This unit adopts the recursive least squares (RLS) algorithm. The slope is iteratively updated once every time a new link quality parameter sampling point is moved into the sliding window queue. The variance calculation adopts a single-channel variance calculation procedure based on the Welford algorithm with the same update period. This method avoids traversing and accumulating the queue data of length N at each sampling point, ensuring high real-time performance and low resource consumption of trend perception on the SDR node.

[0032] The system's coordination mechanism addresses the issue of invalid handover caused by the lag in backup route information in ad hoc networks. When the SDR physical layer trend sensing unit generates a feedforward signal indicating that the primary link is about to fail, its operational logic is limited to performing two actions: First, it sends the feedforward signal to the data plane feedforward switching unit, triggering the switching unit to enter a handover standby state, while maintaining the digital information transmission flow on the primary route; second, it sends the feedforward signal to the SDR physical layer transmitter, triggering the transmitter to actively transmit an SDR physical layer micro-perturbation probe packet to the first-hop node of the backup route cached by the route bypass buffer unit. This probe packet is preferably a short probe frame defined by the physical layer to verify the backup route. The current connectivity of the route at the physical layer; the SDR physical layer micro-perturbation probe packet, specifically implemented as a unique short probe sequence or ultra-short frame defined at the physical layer. This sequence or frame contains a preamble code specifically for probes, distinct from the regular data and control flows, carrying the source node identifier of SDR node A and a unique probe session identifier; the SDR physical layer receiver of the first hop node of the backup route is configured to: when demodulating to the preamble code specifically for probes, bypass the higher-layer protocol stack and generate a physical layer echo at the physical layer or MAC layer; the physical layer echo is also an ultra-short frame corresponding to the structure, and the payload contains a copy of the probe session identifier; the SDR physical layer of SDR node A... Within the micro-perturbation timeout threshold, the physical layer receiver performs a final verification of the physical layer freshness of the backup route by comparing the probe session identifier in the received echo with the identifier transmitted locally. This procedure ensures the reliability of the probe and extremely low processing latency. To reduce the overhead of this active probe, the SDR physical layer trend awareness unit passively monitors background control traffic in the network to obtain the link quality information of the backup route, and feeds it back to the route bypass buffer unit for physical layer trust verification. This ensures that the SDR physical layer transmitter only transmits probe packets to backup routes that have passed this verification. The operation rules of the data plane feedforward switching unit are strictly limited. In the switching standby state, Waiting for the echo report from the SDR physical layer receiver, the handover standby state is released only when the SDR physical layer receiver successfully receives the physical layer echo of the SDR physical layer micro-perturbation probe packet within a preset micro-perturbation timeout threshold, which can be set to 5 milliseconds. Then, the forwarding operation of redirecting the digital information transmission to the verified backup route is executed. If the SDR physical layer receiver does not receive the physical layer echo within the timeout threshold, the data plane feedforward handover unit actively abandons this forwarding operation and triggers the route bypass buffer unit to clear or rebuild its buffer. This mechanism of probing first and then handing over ensures that each data plane handover points to a fresh and valid physical layer path.The data plane feedforward switching unit operates under the following rules: after performing the forwarding operation of redirecting digital information transmission to the backup route, it notifies the primary routing protocol of the primary route failure. It switches data first and then notifies the control architecture to achieve decoupling between the data plane and the control plane of digital information transmission, so that the continuity of the data flow is no longer subject to the time delay inherent in the reconvergence of the primary routing protocol. To avoid unnecessary switching jitter when the link fails slowly, this system also introduces a clock arbitration mechanism and an SDR physical layer trend sensing unit, which calculates the quantified expected failure time based on the mean trend and deterioration slope. The routing bypass cache unit obtains the periodic expected update time of the main routing protocol. The data plane feedforward switching unit is limited to: within the expected failure time. Less than expected update time Only then will it respond to the feedforward signal and initiate the subsequent micro-perturbation detection and switching process. It actively suppresses switching and relies on the update cycle of the control plane itself to smoothly handle the topology change.

[0033] Example 1: This example demonstrates the operation of a disclosed SDR-based ad hoc network dynamic routing control system in a specific scenario. In a highly dynamic ad hoc network composed of multiple UAV SDR nodes, node A transmits digital information streams to node B at high speed via the primary route. Node A then enters an area obstructed by a building, causing a gradual decrease in the signal-to-noise ratio (SNR) of the primary physical link with node B. Multipath effects and interference in the air cause fluctuations in the link quality parameters within the time-series sliding window queue. When monitoring this primary physical link, the SDR physical layer trend sensing unit in the system detects the mean-square value... The differential collaborative arbitration mechanism starts operating. At time T1, noise causes the mean trend calculation value of SNR to briefly exceed the preset feedforward trigger threshold. The variance calculation module of this unit also detects that the variance value is much higher than the preset stability threshold. The SDR physical layer trend sensing unit determines that this drop is caused by noise and actively suppresses the generation of feedforward signals to avoid unnecessary switching. At time T2, when node A goes further into the occlusion area, the link experiences real attenuation, and the mean trend exceeds the feedforward trigger threshold again. At this time, the variance is lower than the stability threshold. The collaborative arbitration logic of this unit determines that the primary link is about to fail and generates a feedforward signal.

[0034] The feedforward signal is transmitted in parallel, and the data plane feedforward switching unit immediately enters the switching standby state. The SDR physical layer transmitter is triggered, and the backup route that has passed passive listening and physical layer trust verification is obtained from the route bypass buffer unit. The SDR physical layer micro-perturbation probe packet is actively transmitted to the first hop node D of the backup route. Within the preset 5-millisecond micro-perturbation timeout threshold, the SDR physical layer receiver successfully receives the physical layer echo from node D. This echo signal confirms the freshness of the backup route at the physical layer. The operation rules of the data plane feedforward switching unit meet the requirements of this echo signal, so the switching standby state is released, and the forwarding operation is performed to seamlessly redirect the digital information transmission of node A to the backup route. After this data plane switching is completed, the data plane feedforward switching unit notifies the primary routing protocol of the primary route failure, triggering the route re-convergence of the control plane. The critical digital information transmission has been running stably on the backup route, and no packet loss has occurred due to the actual interruption of the primary link or the convergence delay of the control plane.

[0035] Example 2: To objectively verify the performance of the system of the present invention in avoiding transmission interruption in high-dynamic scenarios of digital information transmission compared with existing technologies and incomplete solutions, this comparative experiment was set up. The experiment used a network simulation platform, which constructed an SDR self-organizing network topology including nodes A (source), B (destination), C (primary relay), and D (backup relay). The physical channel model in the platform can reproduce the gradual attenuation of the link signal-to-noise ratio (SNR) and instantaneous noise interference. The digital information transmission flow was set as a constant rate UDP service flow of 1000 packets / s from A through C to B. The link hard interruption decision threshold was SNR below 5dB. The feedforward trigger threshold of the SDR physical layer trend sensing unit was set as mean trend slope below -1.5dB / 100ms, the stability threshold was set as variance below 2.0, and the micro-disturbance timeout threshold was set as 5ms. The experiment set up four test groups: control group 1, using the standard routing protocol, relying on Hello packet timeout (set to 800ms) for passive route reconvergence; control group 2, using the active switching frame of the present invention. The structure is as follows: the SDR physical layer trend sensing unit is triggered based on the mean trend and lacks variance collaborative arbitration; control group 3 adopts the active switching architecture of the present invention and has mean-variance collaborative arbitration, but the data plane feedforward switching unit lacks the active verification step of the SDR physical layer micro-disturbance detection packet, and switches immediately upon receiving the feedforward signal; the sample group of the present invention adopts the complete technical solution disclosed, and has both mean-variance collaborative arbitration and micro-disturbance detection packet active verification mechanism; the experiment sets three typical challenge scenarios of digital information transmission: scenario 1 (progressive failure), the primary physical link SNR of node AC drops linearly from 25dB to 0dB within 2 seconds, and the backup path AD remains unobstructed; scenario 2 (instantaneous noise interference), the AC link SNR is at a stable value of 25dB, and a sudden 50ms-long -10dB deep noise spike occurs, which causes the mean trend to briefly exceed the feedforward trigger threshold; scenario 3 (backup path failure), the AC link experiences the same progressive failure as scenario 1, and the backup path AD has already experienced physical layer interruption before the failure occurs.

[0036] Table 1: Data from Comparative Tests on Digital Information Transmission Performance

[0037]

[0038] Referring to Table 1, in Scenario 1, the passive response of Control Group 1 resulted in a handover delay of approximately 802.3 ms and a large number of digital data packets lost. Both the present invention's sample group and Control Group 3 actively avoided this by using feedforward signals, keeping the number of lost packets below 20, thus verifying the effectiveness of the active handover architecture. The present invention's sample group, due to the inclusion of SDR physical layer micro-perturbation detection packet verification, experienced a slight increase in delay of 5.5 ms, but this was still far superior to Control Group 1. In Scenario 2, Control Group 2, lacking variance arbitration, experienced noise spike triggering, resulting in unnecessary false handovers and the loss of 11 data packets. The mean-variance synergy of the present invention's sample group... The arbitration mechanism successfully identified the high variance event as transient noise, suppressed the feedforward signal, avoided erroneous handover, and resulted in zero packet loss. In scenario three, control group 3, lacking verification of the freshness of the backup path, immediately switched to the equally failed AD path when the AC link failed, causing the data stream to be redirected to the failed path, resulting in continuous data loss. In contrast, the SDR physical layer micro-perturbation detection packet mechanism of the present invention, when transmitting detection packets in the handover standby state, timed out due to no echo received. Based on this, the data plane feedforward handover unit determined that the backup path was invalid and actively terminated the handover operation, avoiding invalid handover.

[0039] Example 3: This example combines Figures 1 to 3 This describes a dynamic routing control system for ad hoc networks based on SDR, such as... Figure 1 As shown, the SDR physical layer trend awareness unit continuously monitors the link quality parameters of the primary physical link and predicts failure trends through mean-variance collaborative arbitration. When failure is predicted, it sends two feedforward signals. One feedforward signal triggers a switchover standby and is sent to the data plane feedforward switching unit, which transmits digital information from the primary route. The other feedforward signal triggers an active probe and is sent to the SDR physical layer transmitter. The transmitter obtains a backup route from the route bypass buffer unit, which pre-calculates and buffers the backup route. The SDR physical layer transmitter sends a micro-perturbation probe packet to the backup route. The SDR physical layer receiver is responsible for receiving the probe packet echo and monitoring the physical layer echo or timeout. If an echo confirmation is received, it is sent to the data plane feedforward switching unit. Based on echo verification, the switching unit performs data plane redirection, switching the digital information transmission to the backup route. Only after the switchover is completed does the unit notify the primary route of failure to the control plane of the primary route protocol.

[0040] like Figure 2As shown, its core logic revolves around three main functions: predicting link failure trends, caching backup routes, and performing data plane feedforward switching. The execution of predicting link failure trends relies on the mean-variance collaborative arbitration mechanism, which is associated with the SDR physical layer trend-aware unit entity. The backup route caching function interacts with the main routing protocol entity. The data plane feedforward switching function relies on two sub-mechanisms: actively verifying route freshness and notifying the control plane reconvergence. The route freshness verification mechanism requires interaction with other SDR nodes, while the control plane reconvergence notification mechanism interacts with the main routing protocol entity. Figure 3 As shown, a primary routing protocol, such as OLSR or AODV, runs on the node operating system or basic SDR framework of SDR node A. The software deployed by the dynamic routing control system of this invention is deployed as an independent logical layer under the primary routing protocol. It contains an SDR physical layer trend perception unit, a route bypass caching unit, and a data plane feedforward switching unit. These three software units interact with the SDR physical layer transmitter and SDR physical layer receiver through physical layer interface hardware / drivers. The SDR physical layer transmitter and receiver are responsible for communicating with other SDR nodes B through the primary / backup paths of the self-organizing network physical links. Other SDR nodes B can serve as the first hop node of the backup path.

[0041] Example 4: This example describes the calibration procedures for key parameters within the SDR physical layer trend sensing unit, including the feedforward trigger threshold and stability threshold, and the expected failure time. The calculation and arbitration logic, and the calibration procedure, are completed through offline simulation. This procedure constructs a channel model of a highly dynamic self-organizing network, simulates the gradual attenuation of SNR between vehicle nodes due to movement and obstruction, and sets the expected update time of the main routing protocol. The timeout period is 800ms, corresponding to the Hello packet timeout period. In this procedure, multiple simulations were run, and the SNR of the primary physical link consistently showed a fixed mean trend. The linear regression slope decreased from 25dB until it fell below the 5dB hard interrupt threshold, with instantaneous noise of varying intensities superimposed on the signal. By traversing different mean trend slopes (from -0.5dB / 100ms to -5.0dB / 100ms) and variances (from 0.5 to 5.0), the actual slope and variance of the system's trigger feedforward signal were recorded. Data analysis showed that when the variance exceeded a certain value, set to 2.0, the correlation between the trigger event and the final link failure (SNR below 5dB) decreased, indicating that noise was dominant. Therefore, the stability threshold was set to 2.0. Among the effective attenuation events with variances below 2.0, the mean trend slope of the trigger feedforward signal was selected, and the corresponding expected failure time was calculated. The feedforward trigger threshold is set to all Less than The slowest decay slope corresponding to the event is set to -1.5dB / 100ms. This feedforward trigger threshold setting enables the system to respond to failure trends where the control plane has not had time to update naturally.

[0042] During the actual transmission process, the SDR physical layer trend sensing unit executes the expected failure time based on the calibration threshold. Real-time calculation and arbitration: At time T1, the SDR physical layer trend sensing unit calculates the mean trend of the current primary physical link by using the linear regression slope of the time-series sliding window queue. The current SNR measurement value is -2.1dB / 100ms. =12.8dB, variance 1.3; since the mean trend of -2.1dB / 100ms exceeds the feedforward trigger threshold of -1.5dB / 100ms, and the variance of 1.3 is lower than the stability threshold of 2.0, the collaborative arbitration is passed, and the unit calculation is complete. The calculation logic is as follows: ,in The hard interrupt threshold is 5dB; based on the current measurement. and Calculation yields The data plane feedforward switching unit obtains this. Value 371.4ms and Value 800ms, because The arbitration was successful. The data plane feedforward switching unit responded to the feedforward signal, triggered the SDR physical layer transmitter to transmit the SDR physical layer micro-perturbation detection packet, and started the subsequent switching process.

[0043] Example 5: This example describes the specific procedures for calibrating and initializing key threshold parameters before deploying a specific digital information transmission task. In a vehicle-mounted ad hoc network environment composed of SDR nodes, it ensures that the timeout threshold of the SDR physical layer micro-disturbance detection packet matches the congestion threshold of the route bypass buffer unit. Before the service traffic is loaded, the SDR node performs a two-stage on-site calibration procedure. The first stage of the procedure is used to determine the micro-disturbance timeout threshold. The SDR node sends 1000 SDR physical layer micro-disturbance detection packets to its one-hop neighbor node, records the detected physical layer echo round-trip time (RTT), and calculates the 99th percentile value by statistically analyzing the 1000 collected RTT samples. If the calculated 99th percentile value is 3.8ms, the micro-disturbance timeout is set. The threshold is set to a redundant value of 4.5ms to ensure that the timeout threshold is set based on the actual physical latency characteristics of the current network topology. The second phase of the procedure is used to calibrate the congestion threshold. Based on the set 4.5ms timeout threshold, the SDR node injects simulated service flows into its neighboring nodes, gradually increasing the injection rate and monitoring two indicators: the congestion metric reported by the main routing protocol based on queue latency, and the actual packet loss rate of the digital information transmission flow. Experimental data shows that when the congestion metric is below 62%, the actual packet loss rate remains below 0.1%. When the congestion metric exceeds 62%, the actual packet loss rate begins to show non-linear growth, rapidly climbing to above 5%. 62% is determined to be the congestion inflection point of this specific network, and the congestion threshold of the routing bypass buffer unit is set to 60%.

[0044] Example 6: This example provides a detailed explanation of the background calculation procedure of the routing bypass cache unit and the health threshold calibration procedure of the backup route required for physical layer trust verification. On the SDR node of the ad hoc network, the routing bypass cache unit periodically performs backup route calculation and verification in the background. The primary route is ACB, which carries the digital information transmission flow. The routing bypass cache unit performs topology-disjoint path calculation, inputs the complete topology map provided by the primary routing protocol, identifies the links AC and CB occupied by the primary route ACB, logically deletes these two links from the topology map, and performs a Dijkstra shortest path calculation with A as the source and B as the destination to obtain a backup route ADB, which is topologically disjoint from the primary route.

[0045] After obtaining the topology-disjoint backup route (ADB), the route bypass buffer unit initiates physical layer trust verification. The pre-calibrated backup route health threshold is calibrated according to the following procedure: In an offline simulation environment, a single-hop digital information transmission link is constructed, and the physical layer SNR value of this link is progressively set, traversing from 5dB (hard interruption threshold) to 20dB, with a step size of 1dB. At the SNR setpoint, a constant rate UDP traffic of 1000 packets / s is injected into the link for 1 second, and the packet delivery rate (PDR) is measured during this time period. Experimental data shows that when the SNR is below 9dB, the PDR is below 90%; when the SNR is 10dB, the PDR can reach 95.3%; and when the SNR is above 12dB, the PDR stabilizes above 99%, achieving a balance between availability and transmission quality, ensuring a minimum SNR value of over 95% PDR. The backup route health threshold is set at 10dB. In actual operation, the route bypass cache unit identifies the first-hop link of the backup route ADB as AD and requests the SDR physical layer trend awareness unit to query the link quality. The SDR physical layer trend awareness unit uses its passive listening capability to tune and monitor the background control traffic sent by node D, such as Hello packets of the OLSR protocol, and measures the physical layer signal-to-noise ratio (SNR). The SDR physical layer trend awareness unit compares the measured SNR value, taking a specific measurement value of 12.3dB as an example, with the calibrated 10dB backup route health threshold. Since 12.3dB is greater than 10dB, the link is determined to be healthy, and the route bypass cache unit accordingly sets the backup route ADB to a verified available state and stores it in the cache for the data plane feedforward switching unit to call when it receives a feedforward signal indicating that the primary link has failed.

[0046] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention.

[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A self-organizing network dynamic routing control system based on SDR, characterized in that, The system includes: The route bypass caching unit, based on the topology information of the main routing protocol, pre-calculates and caches backup routes for the primary routes corresponding to the primary physical links carrying digital information transmission. The SDR physical layer trend sensing unit is used to obtain the physical link quality information of the backup routes cached in the route bypass caching unit by passively listening to the background control traffic in the network. The route bypass caching unit is also used to perform physical layer trust verification on the backup routes based on the physical link quality information fed back by the SDR physical layer trend sensing unit. The SDR physical layer transmitter is limited to the first hop node of the backup routes that have passed the physical layer trust verification and transmits SDR physical layer micro-perturbation probe packets. SDR physical layer transmitter; SDR physical layer receiver and data plane feedforward switching unit; The SDR physical layer trend sensing unit is used to calculate the mean trend and variance of the link quality parameters of the primary physical link in the timing sliding window queue in parallel. The SDR physical layer trend sensing unit is limited to generating a feedforward signal that the primary link is about to fail when the mean trend exceeds the preset feedforward trigger threshold and the variance is lower than the preset stability threshold. The SDR physical layer trend sensing unit, when generating the feedforward signal, is also used to: send the feedforward signal to the data plane feedforward switching unit to trigger the data plane feedforward switching unit to enter the switching standby state; and send the feedforward signal to the SDR physical layer transmitter to trigger the SDR physical layer transmitter to actively transmit SDR physical layer micro-disturbance detection packets to the first hop node of the backup route cached by the route bypass cache unit. The data plane feedforward switching unit operates under the following rules: only when the SDR physical layer receiver successfully receives the physical layer echo of the SDR physical layer perturbation detection packet within the preset perturbation timeout threshold will the switching standby state be released and the forwarding operation of redirecting the digital information transmission to the verified backup route be executed. The data plane feedforward switching unit is also used to notify the primary routing protocol of the primary route failure after performing the forwarding operation, thereby triggering the route reconvergence of the primary routing protocol.

2. The SDR-based ad hoc network dynamic routing control system according to claim 1, characterized in that, The SDR physical layer trend sensing unit is also used to monitor the physical layer synchronization status of the primary physical link. When the SDR physical layer trend sensing unit detects a momentary loss of physical layer synchronization status, it immediately generates a feedforward signal indicating that the primary link is about to fail.

3. The SDR-based ad hoc network dynamic routing control system according to claim 1, characterized in that, The backup routes pre-calculated by the route bypass cache unit do not intersect with the primary routes in terms of topology.

4. The SDR-based ad hoc network dynamic routing control system according to claim 1, characterized in that, The SDR physical layer trend-aware unit calculates a quantified expected failure time based on the mean trend. Output expected failure time ; The route bypass cache unit obtains the expected update time of the main routing protocol. The data plane feedforward switching unit is also used to obtain the expected failure time. Compared to the expected update time ; The data plane feedforward switching unit is limited to the expected failure time. Less than expected update time Only when the time is right will the feedforward signal be responded to.

5. A self-organizing network dynamic routing control system based on SDR according to claim 1, characterized in that, The SDR physical layer trend sensing unit achieves mean trend by performing first-order difference calculation or linear regression slope calculation on the time-series sliding window queue of link quality parameters.

6. The SDR-based ad hoc network dynamic routing control system according to claim 1, characterized in that, The route bypass caching unit is also used to obtain the congestion metric generated by the main routing protocol to characterize the link congestion degree; when pre-calculating and caching backup routes, the route bypass caching unit is limited to selecting routes with congestion degrees lower than a preset congestion threshold from multiple candidate backup routes based on the congestion metric, and using them as backup routes.

7. A self-organizing network dynamic routing control system based on SDR according to claim 1, characterized in that, The data plane feedforward switching unit is also limited to the following operating rules: when the SDR physical layer receiver does not receive the physical layer echo within the preset micro-disturbance timeout threshold, it actively abandons the forwarding operation and triggers the routing bypass buffer unit to clear or rebuild its buffer.

8. A self-organizing network dynamic routing control system based on SDR according to claim 1, characterized in that, Link quality parameters include signal-to-noise ratio (SNR) or channel quality indicator (CQI).

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