Congestion control system and control method for jointly adjusting sending rate based on queue and time delay in wireless local area network

Abstract

The invention provides a congestion control system and a control method for jointly adjusting a sending rate based on queues and time delays under a wireless local area network, relates to the technical field of congestion control of the wireless local area network, and aims to solve the problems that a traditional congestion control algorithm depends on single signal sensing, is lagged in response, cannot adapt to bottleneck dynamic switching of the wireless local area network, and is low in cost. And the transmission delay and the link throughput are difficult to balance. According to the method, after each round of data transmission, a network card driving queue residual length RQ is obtained, a data packet round trip time RTT is monitored, a congestion scene is cooperatively judged, a congestion window cwnd is dynamically adjusted to optimize the transmission rate, and corresponding formulas or strategies are adopted for adjustment according to scenes. According to the method, the problems of one-sided sensing and response lag of a traditional congestion control algorithm can be solved, a scene is judged through RQ and RTT dual-sensing cooperation, cwnd is dynamically adjusted, time delay is reduced when the network is good, throughput is guaranteed when the network is poor, and the performance is superior to Cubic and BBR.

Description

Technical Field

[0001] This invention relates to the field of wireless local area network (WLAN) congestion control technology, and in particular to a congestion control system and method for adjusting the transmission rate based on queue and delay in a wireless local area network. Background Technology

[0002] Existing traditional end-to-end congestion control methods include BBR, Cubic, and Vegas, among which... (1) The core idea of ​​the Cubic algorithm is to dynamically adjust the congestion window size of TCP connections based on network congestion. The Cubic algorithm uses a time-based cubic curve function to calculate the size of the congestion window. This allows the congestion window to grow slowly when the network is not congested, but to decrease rapidly when congestion occurs.

[0003] (2) The core idea of ​​the BBR algorithm is to actively detect bottleneck bandwidth in the network. It identifies bottleneck links in the network by sending data and measuring the transmission rate and round-trip time (RTT) of data packets. BBR attempts to find the maximum bandwidth without causing network congestion. Instead of using a congestion window to control the transmission rate, it dynamically adjusts the data transmission rate based on bandwidth estimation to gradually occupy the network bottleneck bandwidth.

[0004] (3) The core idea of ​​the Vegas algorithm is to detect network congestion by monitoring changes in network round-trip time (RTT). It determines whether the network is congested by comparing the actual RTT with the baseline RTT (the RTT under normal conditions). When the actual RTT is significantly higher than the baseline RTT, the Vegas algorithm considers that congestion may have occurred and uses the congestion window growth rate to control the data transmission rate.

[0005] However, the above congestion control methods have the following problems: (1) The Cubic algorithm is the default congestion control algorithm in Linux systems. Its core idea is to dynamically adjust the congestion window size of TCP connections based on network congestion. The Cubic algorithm uses a time-based cubic curve function to calculate the size of the congestion window. The Cubic algorithm will make full use of the link capacity to fill the bottleneck queue as much as possible before packet loss occurs, so it can usually achieve high throughput and link utilization. However, it still increases the congestion window when the bandwidth utilization is high, thereby increasing the packet loss rate and aggravating network jitter. With the development of technology and the decrease in hardware costs, packet loss will not occur when the network is just congested, but the data packets will be stored in the buffer. When packet loss caused by buffer overflow is detected, the buffer has accumulated a large amount of data, which means that the network congestion is already very serious. This results in a certain lag in the sender's judgment of network congestion and a lack of "multi-dimensional real-time perception" capability, that is, relying only on the single feedback signal of "packet loss". It cannot actively capture the dynamic changes of the first-hop queue accumulation, and can only passively wait for the packet loss signal after the congestion intensifies, and the perception of the link is long and the response is not timely. In addition, the buffer expansion problem caused by this approach will lead to a large queuing delay, resulting in excessively high queuing delay.

[0006] (2) BBR dynamically adjusts the data transmission rate based on the network bandwidth and round-trip delay to detect the available link capacity in order to avoid network congestion and maximize data transmission efficiency. However, due to the rapid changes in wireless links, periodic probing may lead to inaccurate bandwidth measurement and performance degradation. In addition, this method takes the instantaneous transmission rate as its main control object. Although it also controls cwnd, Cardwell believes that its control over cwnd only plays an auxiliary role. More importantly, BBR does not reflect the "dynamic response to the environment" characteristic: the periodic probing mechanism cannot adjust the sensing frequency with the real-time fluctuations of the wireless link. This is equivalent to the agent's "sensing rhythm" not matching the "rhythm of environmental change", resulting in bandwidth measurement deviation and inability to adapt to the dynamic environment of wireless LAN.

[0007] (3) Delay-based congestion control algorithms dynamically adjust data transmission rates by monitoring changes in round-trip time (RTT). These algorithms can detect signs of network congestion before packets are lost due to buffer overflow, thus maintaining lower end-to-end latency more effectively, which is crucial for media transmission with high real-time requirements. However, this delay-based control method may take overly conservative rate adjustment measures due to excessive sensitivity to congestion, resulting in the failure to maximize network link utilization. On the other hand, in networks with mixed traffic types, these delay-based algorithms may be at a disadvantage or even starved when competing with congestion control based on packet loss mechanisms because they are not aggressive enough. Essentially, these algorithms lack the logic of "multi-perception dimension collaboration," relying solely on the single environmental signal of "delay," failing to consider both local and global link states, resulting in a one-sided perception dimension and making it difficult to balance "link utilization - competitive advantage" in complex traffic scenarios.

[0008] Traditional algorithms generally suffer from a common problem: they all adopt a "single signal perception - passive behavior adjustment" model, failing to construct an intelligent agent centered on a "congestion control module," and thus unable to achieve a closed loop of "perception (multi-dimensional environmental interaction) - decision-making (quantitative judgment of congestion type) - action (precise adjustment of transmission rate)." However, the core characteristics of the wireless LAN environment are "dynamic bottleneck switching (first hop / non-first hop) and rapid link state fluctuations," making the passive perception and delayed response of traditional algorithms ill-suited to the demands of this environment. Summary of the Invention

[0009] This invention proposes a congestion control system and method for wireless local area networks (WLANs) that adjusts the transmission rate based on queue and latency. The system uses a congestion control module as its core, locally sensing the remaining queue length (RQ) driven by the network interface card to obtain local link load, and globally monitoring the round-trip time (RTT) of data packets to capture the global congestion state. It collaboratively determines first-hop / non-first-hop / no-congestion scenarios and dynamically adjusts the congestion window (cwnd). This solves the problems of traditional congestion control algorithms relying on a single signal sensing, having delayed response, being unable to adapt to dynamic switching of WLAN bottlenecks, and struggling to balance transmission latency and link throughput.

[0010] A congestion control system for wireless local area networks (WLANs) based on joint adjustment of transmission rate using queue and delay parameters includes a congestion control module, a local sensing unit, a global sensing unit, and a rate adjustment unit. The local sensing unit and the global sensing unit are both connected to the congestion control module, and the congestion control module is connected to the rate adjustment unit. The congestion control module is used to make a collaborative judgment based on the remaining queue length RQ and round-trip time RTT, and send the judgment command to the rate adjustment unit. The local sensing unit is used to collect the remaining queue length RQ of the network card driver queue in the wireless local area network to obtain the load status of the local link and upload it to the congestion control module. The global awareness unit is used to monitor the round-trip time (RTT) of data packets to obtain the congestion status of the global link and upload it to the congestion control module. The rate adjustment unit is used to dynamically adjust the congestion window (cwnd) based on the collaborative judgment results of the remaining queue length (RQ) and round-trip time (RTT) to adapt to the first-hop or non-first-hop bottleneck scenarios of the wireless local area network.

[0011] Furthermore, the network card driver queue collected by the local sensing unit is located between the TCP / IP protocol and the network interface controller (NIC), and is a first-in-first-out (FIFO) circular buffer. The remaining queue length RQ is the number of data packets in the circular buffer that have not been sent by the network interface controller after each round of data transmission.

[0012] Furthermore, the round-trip time (RTT) monitored by the global sensing unit includes the current average round-trip time (RTT). average and minimum round-trip time (RTT) min The minimum round-trip time (RTT) min It is the minimum RTT value measured over a period of time, reflecting the inherent transmission time of the network under ideal conditions.

[0013] A congestion control method for wireless local area networks (WLANs) based on joint adjustment of transmission rate using queues and delay, comprising the following steps: S1: After each round of data transmission is completed, obtain the remaining queue length RQ of the network card driver queue in the wireless LAN, and monitor the round-trip time (RTT) of the data packets; S2. Based on the collaborative judgment of the remaining queue length RQ and round-trip time RTT, determine the current congestion scenario of the wireless LAN. The congestion scenario includes first-hop bottleneck, non-first-hop bottleneck or no congestion. S3. Based on the congestion scenario, dynamically adjust the congestion window (cwnd) to adapt to the current link state and optimize the transmission rate.

[0014] Furthermore, in S2, when the remaining queue length RQ is greater than the preset threshold δ1, the adjustment method of S3 includes: If cwnd≥(RQ If the remaining queue length decreases, then cwnd will be reduced according to the following formula: ; If cwnd < (RQ) If the congestion window (cwnd) is halved, then the congestion window (cwnd) will be halved.

[0015] Furthermore, in S2, when the remaining queue length RQ equals 0, the congestion scenario assessment and adjustment methods in S3 include: If the current average round-trip time (RTT) is average With minimum round-trip time (RTT) min The ratio exceeds the preset threshold Then adjust the congestion window cwnd according to the following formula:

[0016] in, This represents the length of the backlog queue calculated based on the portion of the RTT that exceeds the threshold. If the current average round-trip time (RTT) is average With minimum round-trip time (RTT) min The ratio did not exceed the preset threshold. Then increase the congestion window (cwnd) to detect available bandwidth.

[0017] Furthermore, in S2, when the remaining queue length RQ is equal to 0 and the current average round-trip time RTT is... average With minimum round-trip time (RTT) min The ratio did not exceed the preset threshold. If the remaining queue length RQ is detected to be 0 for n consecutive rounds, the congestion window cwnd is increased according to the following formula:

[0018] Where δ2 is the preset window increment step size.

[0019] Furthermore, in S2, when the remaining queue length RQ is greater than 0 and less than the preset threshold δ1, the congestion scenario judgment and adjustment method in S3 include: If global link congestion is detected based on round-trip time (RTT), then the current congestion window (cwnd) remains unchanged. If a non-first-hop bottleneck is detected in the global link based on the round-trip time (RTT), then the concurrency limit (cwnd) should be reduced immediately according to the following formula:

[0020] A storage medium storing a computer program, which, when executed by a processor, implements the congestion control method for adjusting the transmission rate based on queue and delay in a wireless local area network as described above.

[0021] A computer device includes: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the congestion control method for adjusting the transmission rate based on queue and delay in a wireless local area network as described above.

[0022] Compared with the prior art, the present invention achieves the following significant beneficial effects through the above technical solution: This invention introduces an "environment-agent interaction" paradigm, relying on the local network card to drive real-time perception of the remaining queue length (RQ) and comprehensive monitoring of the global round-trip time (RTT), achieving full coverage of all bottleneck scenarios in wireless LANs (both first-hop and non-first-hop scenarios), effectively solving the problem of the limited perception dimension of traditional algorithms. The real-time interaction mechanism, with each round of data transmission as a cycle, significantly shortens the perception-response interval compared to traditional solutions relying on end-to-end ACK feedback, improving the adaptation speed to wireless link fluctuations. Furthermore, it dynamically adjusts the congestion window (c) through quantized thresholds and scenario-based decision-making logic. The invention significantly reduces transmission latency (14% lower than Cubic and 11.3% lower than BBR) when network conditions are good, and maintains stable throughput when network conditions are poor, achieving a dynamic balance between latency and throughput. The quantitative design of the decision logic avoids the conservative or aggressive extreme adjustments of traditional algorithms, improving transmission stability. It has been verified by engineering implementation in Linux kernel and actual routers, and its performance is superior to mainstream algorithms such as Cubic and BBR. It has a wide range of applications and provides a more efficient, stable and adaptable technical solution for wireless LAN congestion control. Attached Figure Description

[0023] Figure 1 This is a flowchart of a congestion control method for adjusting the transmission rate based on queue and delay in a wireless local area network according to the present invention. Figure 2 This is a diagram illustrating the working principle of the network card driver queue. Figure 3 This is a comparison chart of the data packet latency of the present invention with that of Cubic and BBR, wherein, Figure 3 (a) is a comparison chart of the data packet delay of the present invention and Cubic; Figure 3 (b) is a comparison chart of the data packet latency of the present invention and BBR; Figure 4 Scatter plots showing the delay versus throughput for several different congestion control algorithms; Figure 5 The throughput of several different congestion control algorithms is given. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] Reference Figure 1 As shown, a congestion control system for adjusting the transmission rate based on queue and delay in a wireless local area network includes a congestion control module, a local sensing unit, a global sensing unit, and a rate adjustment unit. The local sensing unit and the global sensing unit are both connected to the congestion control module, and the congestion control module is connected to the rate adjustment unit. The congestion control module is used to make a collaborative judgment based on the remaining queue length RQ and round-trip time RTT, and send the judgment command to the rate adjustment unit. The local sensing unit is used to collect the remaining queue length RQ of the network card driver queue in the wireless local area network to obtain the load status of the local link and upload it to the congestion control module. The global awareness unit is used to monitor the round-trip time (RTT) of data packets to obtain the congestion status of the global link and upload it to the congestion control module. The rate adjustment unit is used to dynamically adjust the congestion window (cwnd) based on the collaborative judgment results of the remaining queue length (RQ) and round-trip time (RTT) to adapt to the first-hop or non-first-hop bottleneck scenarios of the wireless local area network.

[0026] Specifically, this invention uses a congestion control system as an intelligent agent in a wireless local area network scenario, with the network card driver queue (RQ) as the local environment perception interface and round-trip time (RTT) as the global environment perception interface. Through real-time interaction with the network environment (collecting RQ after each round of transmission and dynamically monitoring RTT), a perception-decision-action closed loop is constructed: the congestion type (first hop / non-first hop) is determined based on the dual-dimensional perception results, and the transmission rate is adapted by dynamically adjusting the congestion window (cwnd), thus solving the problems of one-sided perception and delayed response in traditional algorithms.

[0027] Furthermore, the network card driver queue collected by the local sensing unit is located between the TCP / IP protocol and the network interface controller (NIC), and is a first-in-first-out (FIFO) circular buffer. The remaining queue length RQ is the number of data packets in the circular buffer that have not been sent by the network interface controller after each round of data transmission.

[0028] Furthermore, the round-trip time (RTT) monitored by the global sensing unit includes the current average round-trip time (RTT). average and minimum round-trip time (RTT) minThe minimum round-trip time (RTT) min It is the minimum RTT value measured over a period of time, reflecting the inherent transmission time of the network under ideal conditions.

[0029] A congestion control method for wireless local area networks (WLANs) based on joint adjustment of transmission rate using queues and delay, based on the aforementioned congestion control system for WLANs based on joint adjustment of transmission rate using queues and delay, is characterized by comprising the following steps: S1: After each round of data transmission is completed, obtain the remaining queue length RQ of the network card driver queue in the wireless LAN, and monitor the round-trip time (RTT) of the data packets; S2. Based on the collaborative judgment of the remaining queue length RQ and round-trip time RTT, determine the current congestion scenario of the wireless LAN. The congestion scenario includes first-hop bottleneck, non-first-hop bottleneck or no congestion. S3. Based on the congestion scenario, dynamically adjust the congestion window (cwnd) to adapt to the current link state and optimize the transmission rate.

[0030] Specifically, when wireless terminal data transmission applications face rapid changes in link congestion, the delayed adjustment of the transmission rate may lead to a decline in user experience. To mitigate this issue, this invention designs a congestion control method based on jointly adjusting the transmission rate according to the drive queue length and latency. This method mainly adjusts the congestion limit (cwnd) based on the remaining queue length after each round of wireless network card transmission. When the queue length is large, cwnd will decrease rapidly to alleviate congestion, while when the queue length is small, cwnd will gradually increase to improve link utilization. Since obtaining local congestion information at the sender is much shorter than waiting for end-to-end ACK feedback, this invention can track real-time changes in wireless link capacity more quickly and accurately.

[0031] The core of this solution is a dual-dimensional perception-dynamic decision-making-precise action logic: by coordinating local perception (RQ) and global perception (RTT), the specific congestion scenario of the network environment is determined, and then an appropriate cwnd adjustment action is output to ensure that the agent's behavior is highly matched with the environmental state.

[0032] While the bottleneck is usually the first hop, it can also occur on the link from the router to the receiver. Therefore, relying solely on the driving queue method is inaccurate and incomplete. This paper proposes a control strategy incorporating RTT (Round-Trip Time). RTT is a crucial indicator in network communication. Although the sender cannot accurately determine the link congestion status based on the driving queue length when congestion doesn't occur at the first hop, changes in packet queuing delay caused by congestion can be captured by the sender based on RTT changes. When the system detects an excessively high RTT, it indicates a large number of packets are accumulating at a node in the link, causing significant queuing delay. Therefore, it is necessary to immediately reduce the congestion window to alleviate link congestion.

[0033] The network interface card (NIC) driver queue (RQ) resides between the TCP / IP protocol and the NIC, typically implemented as a first-in, first-out (FIFO) circular buffer. When a host transmits a data packet, it first injects the packet into the circular buffer. Then, the NIC reads the packet, sends it out, and clears the circular buffer after successful transmission. Its specific workflow is as follows: Figure 2 As shown.

[0034] RTT (Round-Trip Time) refers to the total time it takes for a data packet to travel from the sender to the receiver, through the network, and back to the sender with an acknowledgment (ACK). When the number of data packets in the network exceeds the link's processing capacity, packets will wait in queues at congestion points, resulting in significant queuing delays and thus increasing the RTT.

[0035] RTT in the following text min This refers to the minimum RTT value measured over a period of time. min The corresponding data packets typically experience almost no queuing delay in the link, reflecting the inherent transmission time of the network under ideal conditions. Therefore, RTT (Round-Trip Time) min It is a relatively stable reference value that can be used to help evaluate network latency performance. By comparing the current RTT with the minimum RTT, the TCP protocol can more accurately determine whether the network is congested. If the current RTT is significantly higher than the minimum RTT, it indicates that there may be congestion in the network, and the sending rate needs to be adjusted.

[0036] In this embodiment, RTT is the global environment awareness unit: when local awareness (RQ) cannot cover non-first-hop bottlenecks, changes in RTT can capture the cumulative effect of the agent's sending behavior in the global link environment; that is, the accumulation of data packets at non-first-hop nodes directly leads to an increase in RTT. This is achieved by comparing the current RTT with the current RTT. minBy using the ratio of [value], the intelligent agent can quantify the congestion level of the global environment, making up for the limitations of single local perception and achieving full-scene environment coverage perception of both local and global scenarios.

[0037] Specifically, when entering the congestion avoidance phase, this scheme mainly adjusts the congestion window based on the following three situations: Long Remaining Queue (First-Hop Bottleneck): When the congestion control module detects through the Local Sense Unit (RQ) that the number of packets sent exceeds the delay-bandwidth product (BDP, i.e., the product of the maximum throughput when the pipe is full and the minimum RTT when the pipe is not full), it indicates that the link is congested and the sending rate should be reduced. Therefore, this algorithm sets a remaining queue threshold. When the remaining queue length (RQ) is detected to be greater than this threshold after each round of network card transmission, the sender will reduce cwnd accordingly based on the difference between RQ and the threshold to reduce the remaining queue length:

[0038] If cwnd is less than (RQ) (This can be solved by simply halving the congestion window.)

[0039] Empty Remaining Queue (Global Congestion / Resource Idle Scenario): When the congestion control module detects a remaining queue length of 0 through the Local Awareness Unit (RQ), it indicates that congestion may not have occurred or the bottleneck link is not in the first hop. In this case, the Global Awareness Unit needs to be activated to compare the current RTT. average The ratio to the minimum RTT. If the current RTT... average The ratio of the minimum RTT exceeds the threshold. If the RTT is high, it indicates the existence of a bottleneck beyond the first hop. In this case, it's necessary to calculate the number of packets piling up on the bottleneck link (the packets causing the increased RTT) based on the RTT value and throughput (converted into packet count), and adjust the congestion window accordingly. If the RTT... average If the ratio to the minimum RTT does not exceed the threshold, it indicates that congestion has not yet occurred, and available bandwidth can be further probed. Therefore, when the remaining queue length is equal to 0, there are two cases: (1) When RTT average If the ratio of the minimum RTT to the minimum RTT exceeds the threshold, then cwnd needs to be adjusted according to the following formula:

[0040] in This represents the length of the stacking queue calculated based on the portion of the RTT that exceeds the threshold.

[0041] (2) When RTT averageIf the ratio of the minimum RTT to the minimum RTT does not exceed the threshold, the congestion window needs to be appropriately increased to fully utilize the link. This algorithm uses a window increment step. This is used to detect available capacity. However, when the dequeue rate is much greater than the inqueue rate, a fixed increment will cause cwnd to grow too slowly. Therefore, if the remaining queue length is detected to be 0 for n consecutive rounds, the increment of cwnd can be set to... Adjust cwnd according to the following formula:

[0042] Appropriate remaining queue (local balancing + global verification scenario): When the congestion control module detects through the local sensing unit (RQ) that the remaining queue length is greater than 0 and less than the threshold... At this time, the sending end judges that the first hop link is fully utilized and there will be no long queuing delay. However, at this time, the data packets may accumulate on other nodes. Therefore, in this case, it is still necessary to judge whether data accumulation occurs on other nodes of the link based on the current RTT. Therefore, the congestion window will be adjusted according to the following two situations: (1) When it is detected that there is no congestion on other links according to the RTT, the congestion window (cwnd) can be kept unchanged; (2) When it is detected that there is a bottleneck on the external link according to the RTT, the congestion window (cwnd) will be reduced immediately.

[0043] A storage medium storing a computer program, which, when executed by a processor, implements the congestion control method for adjusting the transmission rate based on queue and delay in a wireless local area network as described above.

[0044] Specifically, the storage medium of this invention stores a corresponding computer program, enabling the program to fully leverage the core technological advantages of queue-delay joint adjustment when executed by a processor. Relying on the local network card to drive real-time load awareness of the remaining queue length (RQ) and global round-trip time (RTT) congestion state monitoring, it achieves comprehensive coverage of all bottleneck scenarios in both first-hop and non-first-hop wireless LANs, effectively solving the problem that traditional congestion control algorithms rely solely on single signal perception and have limited adaptability. The real-time interaction mechanism, with each round of data transmission as a cycle during program execution, significantly shortens the interval between perception and adjustment, enabling rapid... It responds quickly to the dynamic fluctuations of wireless links, avoiding the congestion judgment lag problem caused by the reliance on end-to-end feedback in traditional algorithms. By dynamically optimizing the congestion window (cwnd) through quantified thresholds and scenario-based decision logic, it can effectively reduce transmission latency when the network condition is good and stably guarantee link throughput when the network condition is poor, achieving a dynamic balance between latency and throughput. Moreover, after engineering verification in the Linux kernel and actual routers, its performance is superior to mainstream algorithms such as Cubic and BBR. It can be quickly deployed without additional complex configuration, providing efficient, stable and highly adaptable technical support for wireless LAN congestion control.

[0045] A computer device includes: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the congestion control method for adjusting the transmission rate based on queue and delay in a wireless local area network as described above.

[0046] Specifically, the computer device of this invention stores the corresponding computer program in the memory. Relying on the collaborative work of the processor and the memory, it provides a reliable hardware carrier for the implementation of congestion control schemes. When the processor executes the program, it can efficiently realize the core logic of queue-latency joint adjustment: it can not only complete the local load perception of the remaining queue length (RQ) of the network card after each round of data transmission in real time, but also accurately monitor the round-trip time (RTT) of data packets to capture the global congestion state. Then, through collaborative judgment, it can identify the first-hop bottleneck, non-first-hop bottleneck and congestion-free scenarios of the wireless LAN, and dynamically adjust the congestion window (cwnd) to adapt to the link state. During the execution of the program, the device effectively solves the problems of traditional congestion control algorithms relying on a single signal perception and response lag, and avoids the high latency caused by the buffer expansion of the Cubic algorithm and the poor adaptability of the periodic detection of the BBR algorithm. It can reduce transmission latency when the network condition is good, and can stably guarantee throughput when the network condition is poor, achieving a dynamic balance between latency and throughput. Moreover, after engineering verification in the Linux kernel and actual routers, its performance is better than mainstream algorithms such as Cubic and BBR, and it can be integrated into the wireless LAN environment without additional complex configuration.

[0047] This invention was deployed in the Linux kernel and tested in different network environments, referring to... Figure 3 As shown, the test results demonstrate that the solution proposed in this invention is superior to the current default congestion control algorithm Cubic in Linux systems, which is based on Google's BBR.

[0048] Since there is no difference between 90Mbps and 88Mbps for users when network conditions are good, this solution's congestion control module prioritizes reducing latency during such periods. It accurately determines congestion-free states through a dual-sensor approach (local + global), avoiding queuing delays caused by blindly increasing window size in traditional algorithms. Figure 2 The graph shows the latency results of this scheme compared to Cubic and BBR in a single test. It is clear from the graph that the latency per data packet is significantly lower when using this invention compared to the Cubic and BBR algorithms. We conducted 10 experiments on the data packet latency produced by each of the three schemes and calculated the average RTT. Under relatively good network conditions, the average data packet latency of this scheme is reduced by 14% and 11.3% compared to Cubic and BBR, respectively. Figure 4 The diagram shows scatter plots of delay versus throughput at the P95 quantile for several different congestion control algorithms under this network condition. It can be observed that, combined, the performance of this invention outperforms Cubic, BBR, and other congestion control algorithms. Essentially, the perception-decision-action closed loop achieves a dynamic balance between delay and throughput.

[0049] However, when network conditions are poor, user experience is often directly related to network throughput. Figure 5 The diagram illustrates a scenario where chload=900, indicating extremely poor network conditions and heavy router activity. Throughput graphs for three different congestion control algorithms show that the transmission rate using this scheme is significantly higher than that of Cubic and BBR.

[0050] The advantages of this invention stem from its "multi-dimensional perception-dynamic interaction" characteristics, which are specifically reflected in three aspects: Full-scene perception enhances adaptability: Compared with the traditional algorithm's single perception (packet loss, single latency), this solution uses RQ (local) + RTT (global) dual perception to cover all bottleneck scenarios of the first hop / non-first hop of the wireless LAN, reducing latency when the network is good and maintaining throughput when the network is poor. Real-time interaction improves response speed: Environmental data (RQ, RTT) is collected in cycles of each round of transmission. Compared with the end-to-end lag feedback that relies on ACK in traditional algorithms, the perception-action interval is shorter and can be quickly adjusted when the wireless link fluctuates. Quantitative decision-making enhances stability: By quantifying the environmental state through thresholds such as δ1, α, and δ2, the perceived signals are transformed into precise actions, avoiding the extreme adjustments of traditional algorithms that are conservative or aggressive, and achieving a performance balance.

[0051] In summary, the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit it. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A congestion control system for wireless local area networks based on joint adjustment of transmission rate using queues and delay, characterized in that, It includes a congestion control module, a local sensing unit, a global sensing unit, and a rate adjustment unit. The local sensing unit and the global sensing unit are both connected to the congestion control module, and the congestion control module is connected to the rate adjustment unit. The congestion control module is used to make a collaborative judgment based on the remaining queue length RQ and round-trip time RTT, and send the judgment command to the rate adjustment unit. The local sensing unit is used to collect the remaining queue length RQ of the network card driver queue in the wireless local area network to obtain the load status of the local link and upload it to the congestion control module. The global awareness unit is used to monitor the round-trip time (RTT) of data packets to obtain the congestion status of the global link and upload it to the congestion control module. The rate adjustment unit is used to dynamically adjust the congestion window (cwnd) based on the collaborative judgment results of the remaining queue length (RQ) and round-trip time (RTT) to adapt to the first-hop or non-first-hop bottleneck scenarios of the wireless local area network.

2. The congestion control system for wireless local area networks based on joint adjustment of transmission rate using queues and delay as described in claim 1, characterized in that, The network card driver queue collected by the local sensing unit is located between the TCP / IP protocol and the network interface controller (NIC), and is a first-in-first-out (FIFO) circular buffer. The remaining queue length RQ is the number of data packets in the circular buffer that have not been sent by the network interface controller after each round of data transmission.

3. The congestion control system for adjusting transmission rate based on queue and delay in a wireless local area network according to claim 1, characterized in that, The round-trip time (RTT) monitored by the global sensing unit includes the current average round-trip time (RTT). average and minimum round-trip time (RTT) min The minimum round-trip time (RTT) min It is the minimum RTT value measured over a period of time, reflecting the inherent transmission time of the network under ideal conditions.

4. A congestion control method for wireless local area networks based on joint adjustment of transmission rate using queues and delay, based on the congestion control system for wireless local area networks based on joint adjustment of transmission rate using queues and delay as described in claims 1-3, characterized in that... Includes the following steps: S1: After each round of data transmission is completed, obtain the remaining queue length RQ of the network card driver queue in the wireless LAN, and monitor the round-trip time (RTT) of the data packets; S2. Based on the collaborative judgment of the remaining queue length RQ and round-trip time RTT, determine the current congestion scenario of the wireless LAN. The congestion scenario includes first-hop bottleneck, non-first-hop bottleneck or no congestion. S3. Based on the congestion scenario, dynamically adjust the congestion window (cwnd) to adapt to the current link state and optimize the transmission rate.

5. The congestion control method for wireless local area networks based on joint adjustment of transmission rate using queues and delay according to claim 4, characterized in that, In S2, when the remaining queue length RQ is greater than the preset threshold δ1, the adjustment methods in S3 include: If cwnd≥(RQ If the remaining queue length decreases, then cwnd will be reduced according to the following formula: ； If cwnd < (RQ) If the congestion window (cwnd) is halved, then the congestion window (cwnd) will be halved.

6. The congestion control method for wireless local area networks based on joint adjustment of transmission rate using queues and delay according to claim 4, characterized in that, In S2, when the remaining queue length RQ equals 0, the congestion scenario assessment and adjustment methods in S3 include: If the current average round-trip time (RTT) is average With minimum round-trip time (RTT) min The ratio exceeds the preset threshold Then adjust the congestion window cwnd according to the following formula: in, This represents the length of the backlog queue calculated based on the portion of the RTT that exceeds the threshold. If the current average round-trip time (RTT) is average With minimum round-trip time (RTT) min The ratio did not exceed the preset threshold. If so, increase the congestion window (cwnd) to detect available bandwidth.

7. The congestion control method for wireless local area networks based on joint adjustment of transmission rate using queues and delay according to claim 6, characterized in that, In S2, when the remaining queue length RQ is equal to 0 and the current average round-trip time RTT is... average With minimum round-trip time (RTT) min The ratio did not exceed the preset threshold. If the remaining queue length RQ is detected to be 0 for n consecutive rounds, the congestion window cwnd is increased according to the following formula: Where δ2 is the preset window increment step size.

8. The congestion control method for wireless local area networks based on joint adjustment of transmission rate using queues and delay according to claim 4, characterized in that, In S2, when the remaining queue length RQ is greater than 0 and less than the preset threshold δ1, the congestion scenario judgment and adjustment method in S3 include: If global link congestion is detected based on round-trip time (RTT), then the current congestion window (cwnd) remains unchanged. If a non-first-hop bottleneck is detected in the global link based on the round-trip time (RTT), then the concurrency limit (cwnd) should be reduced immediately according to the following formula: 。 9. A storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the congestion control method for adjusting the transmission rate based on queue and delay in a wireless local area network as described in any one of claims 4-8.

10. A computer device, characterized in that, include: The device includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the congestion control method for adjusting the transmission rate based on queue and delay in a wireless local area network as described in any one of claims 4-8.

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