A TCP layer timeout retransmission optimization method and apparatus

Abstract

This invention relates to a TCP layer timeout retransmission optimization method and apparatus, belonging to the field of Wi-Fi wireless communication technology. The TCP layer timeout retransmission optimization method includes: acquiring transmission result information of each data frame in the MAC layer; determining channel state index parameters of the MAC layer within a target time period based on the transmission result information; and determining a retransmission strategy for the TCP layer based on the channel state index parameters after the TCP layer detects an ACK timeout event. This invention optimizes the TCP layer timeout retransmission strategy, ensuring the data throughput of the Wi-Fi wireless communication system and effectively improving the data transmission performance of the Wi-Fi wireless communication system.

Description

Technical Field

[0001] This invention relates to the field of WIFI wireless communication technology, and in particular to a method and apparatus for optimizing timeout retransmission at the TCP layer. Background Technology

[0002] The reliable transmission mechanisms of the Transmission Control Protocol (TCP) include Acknowledgment (ACK) and timeout retransmission. In the TCP acknowledgment mechanism, the TCP protocol requires the receiver to reply with an ACK packet to the sender after receiving data, indicating the sequence number of the next segment it expects to receive. If the sender does not receive an ACK packet within a certain time, it will time out and retransmit. In the TCP retransmission mechanism, TCP starts a timeout retransmission timer when sending a segment. If the retransmission timer expires without receiving an ACK packet for the TCP segment, the sender retransmits the TCP segment with the corresponding sequence number until successful transmission.

[0003] According to the IEEE 802.11 protocol specification, in existing Wireless Fidelity (Wi-Fi) communication systems, the TCP layer is responsible for reliable end-to-end data transmission, while the Medium Access Control (MAC) layer is responsible for data frame transmission at the link layer. In complex wireless channel environments, such as high interference or device movement, the MAC layer may frequently lose frames and retransmit them. However, the TCP layer is unaware of this and only judges the network status based on ACK loss or timeout. Once MAC layer retransmission fails or delays cause ACK responses to be untimely, the TCP layer may misjudge it as network congestion, thereby triggering congestion control mechanisms, reducing the sending window, and thus affecting system throughput. Summary of the Invention

[0004] In view of this, it is necessary to provide a TCP layer timeout retransmission optimization method and apparatus to solve the problem that the existing WIFI wireless communication system's TCP layer timeout retransmission mechanism may reduce the sending window and thus affect the system throughput.

[0005] To address the aforementioned problems, in a first aspect, the present invention provides a TCP layer timeout retransmission optimization method, comprising:

[0006] Obtain the transmission result information of each data frame in the MAC layer, and determine the channel state index parameters of the MAC layer within the target time period based on the transmission result information;

[0007] After the TCP layer detects an ACK timeout event, it determines the retransmission strategy of the TCP layer based on the channel state index parameters.

[0008] The target time period is the first time period before the TCP layer detects the ACK timeout event. The transmission result information includes the initial transmission timestamp, retransmission count, successful transmission status, and ACK return time. The channel state index parameters include the average retransmission count, successful transmission rate, instantaneous packet loss rate, round-trip delay trend, and transmission rate trend.

[0009] In one possible implementation, determining the TCP layer retransmission strategy based on the channel state indicator parameters includes:

[0010] The channel quality of the MAC layer is evaluated based on the channel state index parameters to obtain the channel quality evaluation result of the MAC layer.

[0011] If the channel quality evaluation result is unstable, the TCP layer retransmission mechanism will be initiated after the second time period.

[0012] If the channel quality evaluation result is stable, immediately initiate the retransmission of the data frame corresponding to the ACK timeout event, and initiate the congestion control mechanism of the TCP layer.

[0013] In one possible implementation, the step of evaluating the channel quality of the MAC layer based on the channel state index parameters to obtain the channel quality evaluation result of the MAC layer includes:

[0014] Based on the channel state index parameters, namely the channel SNR, channel RSSI, and channel idle rate of the MAC layer, the channel quality of the MAC layer is evaluated to obtain the channel quality evaluation result of the MAC layer.

[0015] In one possible implementation, the evaluation of the channel quality of the MAC layer based on the channel state index parameters, namely the channel SNR, channel RSSI, and channel idle rate of the MAC layer, to obtain the channel quality evaluation result of the MAC layer, includes:

[0016] The channel quality result of the MAC layer is unstable if any of the following conditions are not met, and stable if all of the following conditions are met:

[0017] The average number of retransmissions is less than the first value;

[0018] The success rate of sending the message is greater than the second value;

[0019] The instantaneous packet loss rate is less than the third value;

[0020] The trend of round-trip time delay is stable or decreasing;

[0021] The transmission rate shows a stable or increasing trend;

[0022] The channel SNR is greater than the fourth value;

[0023] The channel RSSI is greater than the fifth value;

[0024] The channel idle rate is greater than the sixth value.

[0025] In one possible implementation, the method further includes:

[0026] Based on the average RTT, RTT standard deviation, average number of retransmissions, average delay of ACK return, packet loss rate, and frequency of duplicate ACKs of data frames in the MAC layer during the target time period, the average SNR and average RSSI of the MAC layer during the target time period, the current congestion window size of the TCP layer, the maximum number of retransmissions of data frames in the MAC layer, the RTO baseline value of the TCP layer, the congestion window growth mode, and the fast retransmission enabled status are adjusted.

[0027] In one possible implementation, the adjustment based on the average RTT, RTT standard deviation, average retransmission count, average ACK return delay, packet loss rate, and duplicate ACK frequency of data frames within the MAC layer during the target time period, the average SNR and average RSSI of the MAC layer during the target time period, the current congestion window size of the TCP layer, the maximum retransmission count of data frames within the MAC layer, the RTO baseline value of the TCP layer, the congestion window growth mode, and the fast retransmission enabled status includes:

[0028] The average RTT, RTT standard deviation, average retransmission count, average ACK return delay, packet loss rate, and duplicate ACK frequency of data frames in the MAC layer during the target time period, the average SNR and average RSSI of the MAC layer during the target time period, and the current congestion window size of the TCP layer are used as inputs to the policy adjustment model. The maximum retransmission count of data frames in the MAC layer, the RTO baseline value of the TCP layer, the congestion window growth mode, and the fast retransmission enabled status are obtained from the output of the policy adjustment model.

[0029] The policy adjustment model is trained on the XGBoost model based on sample data carrying policy labels.

[0030] In one possible implementation, the sample data is obtained by conducting data communication tests under different channel quality, bandwidth, and interference modes.

[0031] On the other hand, the present invention also provides a TCP layer timeout retransmission optimization apparatus, comprising:

[0032] The acquisition module is used to acquire the transmission result information of each data frame in the MAC layer, and determine the channel state index parameters of the MAC layer within the target time period based on the transmission result information.

[0033] The determination module is used to determine the retransmission strategy of the TCP layer based on the channel state index parameters after the TCP layer detects an ACK timeout event.

[0034] The target time period is the first time period before the TCP layer detects the ACK timeout event. The transmission result information includes the initial transmission timestamp, retransmission count, successful transmission status, and ACK return time. The channel state index parameters include the average retransmission count, successful transmission rate, instantaneous packet loss rate, round-trip delay trend, and transmission rate trend.

[0035] Secondly, the present invention also provides a wireless access device, including a memory and a processor, wherein,

[0036] The memory is used to store programs;

[0037] The processor, coupled to the memory, is used to execute the program stored in the memory to implement the steps in the TCP layer timeout retransmission optimization method described in any of the above implementations.

[0038] Thirdly, the present invention also provides a computer-readable storage medium for storing a computer-readable program or instruction, which, when executed by a processor, can implement the steps in the TCP layer timeout retransmission optimization method described in any of the above implementations.

[0039] The beneficial effects of this invention are as follows: The TCP layer timeout retransmission optimization method and apparatus provided by this invention, without changing the original protocol flow, obtains the transmission result information of each data frame in the MAC layer and determines the channel state index parameters of the MAC layer, enabling the TCP layer to have a more accurate perception of the MAC layer link status, avoiding blind retransmission or incorrect judgment of network congestion. Under common WIFI environment problems such as multipath interference, weak signal, and sudden packet loss, it assists the TCP layer in making more reasonable timeout retransmission strategy adjustments. By optimizing the TCP layer timeout retransmission strategy, this invention ensures the data throughput of the WIFI wireless communication system and effectively improves the data transmission performance of the WIFI wireless communication system. Attached Figure Description

[0040] Figure 1 This is a schematic flowchart of an embodiment of the TCP layer timeout retransmission optimization method provided by the present invention;

[0041] Figure 2 A schematic diagram of an embodiment of the improved protocol stack in the WIFI wireless communication system provided by the present invention;

[0042] Figure 3 A schematic diagram of an embodiment of the TCP layer timeout retransmission optimization device provided by the present invention;

[0043] Figure 4 This is a schematic diagram of an embodiment of the wireless access device provided by the present invention. Detailed Implementation

[0044] 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 a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0045] In the description of the embodiments of the present invention, unless otherwise stated, "multiple" means two or more. "And / or" describes the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone.

[0046] The terms "first," "second," etc., used in the embodiments of this invention are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a technical feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature.

[0047] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0048] Before demonstrating the embodiments, the following terms will be explained.

[0049] A WIFI wireless transmission network mainly consists of two parts: an access controller (AC) and a wireless access point (AP). Terminal devices access the Internet through the AP.

[0050] The AP protocol stack of a Wi-Fi wireless transmission network mainly consists of five layers: application layer, transport layer, network layer, data link layer, and physical layer. Data transmitted in the network primarily establishes different transmission connections through the transport layer. Before data can be transmitted between different terminals in a Wi-Fi network, it needs to be encapsulated by different protocol layers. First, different transport protocol headers are added to the data according to different transport protocols. The encapsulated data then enters the network layer. The network protocol (Internet Protocol, IP) at the network layer adds the source and destination network addresses of both the sender and receiver to the header of received data packets. After the encapsulated data enters the data link layer, it converts the upper-layer data packets into corresponding frames and adds a MAC address to the frame header. Each MAC address corresponds to a transmission link, therefore MAC addresses are unique. The encapsulated data can find the correct transmission link based on the MAC address header. Finally, the data is converted into a bit stream at the physical layer and transmitted over the physical link.

[0051] TCP's reliable transmission mechanisms include the ACK mechanism and the timeout retransmission mechanism. In the TCP acknowledgment mechanism, the TCP protocol requires the receiver to reply with an ACK packet to the sender after receiving data, indicating the sequence number of the next segment it expects to receive. If the sender does not receive an ACK packet within a certain time, it will time out and retransmit. In the TCP retransmission mechanism, TCP starts a timeout retransmission timer when sending a segment. If the retransmission timer expires and an ACK packet for the TCP segment is not received, the sender retransmits the TCP segment with the corresponding sequence number until successful transmission.

[0052] Unlike other link layer protocols, to ensure reliable transmission at the MAC layer, 802.11 requires the receiving end to acknowledge received data frames: that is, the sending end sends one or a group of data frames through the wireless channel, and after receiving the data, the receiving end needs to reply with an acknowledgment frame at the MAC layer (MAC layer acknowledgment frames include ACK frames and BlockACK frames, which will be referred to as MAC-ACK in the following text). After receiving the MAC-ACK, the sending end can send a new MAC frame; if the MAC-ACK is not received after a certain period of time, the sending end will retransmit it.

[0053] Wireless Local Area Networks (WLANs) are characterized by openness, time-varying nature, and mobility, making them susceptible to various factors such as multipath propagation, attenuation, external noise, sudden interference, and handover. This results in a high Packet Error Rate (PER) and severe burst packet loss over the air interface, significantly degrading the performance, efficiency, and stability of the TCP protocol in wireless networks. TCP's congestion control mechanism attributes all packet loss to network congestion and uses congestion control algorithms for processing. However, if over-the-air packet loss occurs in a wireless network, TCP will also treat it as network congestion, performing unnecessary congestion control, reducing the congestion window, and lowering the transmission rate. This leads to idle bandwidth in the wireless network, severely degrading network throughput.

[0054] This invention provides a method and apparatus for optimizing timeout retransmission in the TCP layer, which will be described below.

[0055] Figure 1 This is a schematic flowchart of an embodiment of the TCP layer timeout retransmission optimization method provided by the present invention, as shown below. Figure 1 As shown, TCP layer timeout retransmission optimization methods include:

[0056] S101. Obtain the transmission result information of each data frame in the MAC layer, and determine the channel state index parameters of the MAC layer within the target time period based on the transmission result information.

[0057] The target time period is the first time period before the TCP layer detects the ACK timeout event. The transmission result information includes the initial transmission timestamp, retransmission count, successful transmission status, and ACK return time. The channel state index parameters include the average retransmission count, successful transmission rate, instantaneous packet loss rate, round-trip delay trend, and transmission rate trend.

[0058] It should be noted that: combination Figure 2 This invention embeds a MAC layer transmission adaptation layer module between the MAC sublayer and the logical link layer of the Wi-Fi protocol stack to obtain the transmission result information of each data frame in the MAC layer, and determines the channel state index parameters of the MAC layer within the target time period based on the transmission result information. It does not affect the basic data frame transmission and reception process of the existing MAC layer, but records and analyzes the frame transmission behavior in a non-blocking manner after the data frame transmission is completed. Its deployment does not require modification of the core structure of the Wi-Fi protocol stack, thus exhibiting good compatibility and scalability.

[0059] Whenever the MAC layer completes the transmission of a data frame, regardless of whether the frame successfully reaches the receiver, the MAC layer transmission adaptation layer module immediately obtains the transmission result information of that frame. This information includes the initial transmission timestamp, number of retransmissions, success status, and ACK return time. If possible, physical layer parameters such as the modulation scheme and transmission rate used in the data frame can also be obtained. Using this information, the MAC layer transmission adaptation layer module can determine the instantaneous transmission characteristics of the link.

[0060] Furthermore, the MAC layer transmission adaptation layer module can statistically analyze and model the transmission behavior of multiple consecutive data frames, forming a set of index parameters reflecting the current channel state. These channel state index parameters can include average retransmission count, successful transmission rate, instantaneous packet loss rate, round-trip time (RTT) trend, and transmission rate trend. Additionally, the channel state index parameters can also include physical layer bit error rate information, current carrier-to-interference-plus-noise ratio (CINR), and other parameters. These parameters are updated in real time using a sliding window to ensure they represent the true link quality within the current time period. In this invention, the sliding window is the first time period (e.g., 60 seconds) before the TCP layer detects an ACK timeout event.

[0061] The MAC layer transmission adaptation layer module has an internal caching mechanism to temporarily store the aforementioned statistical information for easy access by the upload protocol layer. The cache is managed using a time window or frame count window to prevent historical data from interfering with current status judgments, and the statistical granularity can be set according to different business needs.

[0062] S102. After the TCP layer detects an ACK timeout event, the retransmission strategy of the TCP layer is determined based on the channel state index parameters.

[0063] It should be noted that, to enable the link layer to assist the TCP layer, the MAC layer transport adaptation layer module provides a status query interface to the upper transport layer. When the TCP layer initiates a query request (e.g., during congestion window adjustment, slow start, or fast retransmission), this module can immediately return the link status data within the current statistical window. Based on this information, the TCP layer can optimize its congestion control, rate control, timeout retransmission, and other mechanisms, thereby avoiding transmission performance degradation caused by underlying link anomalies.

[0064] This invention is applicable to WIFI wireless data communication scenarios, especially wireless data communication scenarios where problems such as multipath interference, weak signals, and sudden packet loss frequently occur, such as mobile phone communication scenarios in subway tunnels.

[0065] In summary, the TCP layer timeout retransmission optimization method provided in this embodiment of the invention, without changing the original protocol flow, obtains the transmission result information of each data frame in the MAC layer and determines the channel state index parameters of the MAC layer. This enables the TCP layer to have a more accurate perception of the MAC layer link status, avoiding blind retransmission or incorrect judgment of network congestion. Under common WIFI environment problems such as multipath interference, weak signal, and sudden packet loss, it assists the TCP layer in making more reasonable timeout retransmission strategy adjustments. By optimizing the TCP layer timeout retransmission strategy, this invention ensures the data throughput of the WIFI wireless communication system and effectively improves the data transmission performance of the WIFI wireless communication system.

[0066] In some embodiments of the present invention, determining the retransmission strategy of the TCP layer based on the channel state index parameters includes:

[0067] The channel quality of the MAC layer is evaluated based on the channel state index parameters to obtain the channel quality evaluation result of the MAC layer.

[0068] If the channel quality evaluation result is unstable, the TCP layer retransmission mechanism will be initiated after the second time period.

[0069] If the channel quality evaluation result is stable, immediately initiate the retransmission of the data frame corresponding to the ACK timeout event, and initiate the congestion control mechanism of the TCP layer.

[0070] It's important to note that in traditional TCP protocols, once an ACK timeout event occurs (i.e., no ACK is received from the peer within the set retransmission timeout period RTO), TCP typically immediately determines it as packet loss and initiates retransmission mechanisms and corresponding congestion control procedures, such as reducing the congestion window or entering slow start. However, this strategy often causes performance issues in wireless or dynamic link environments. Because ACK timeouts in wireless networks may originate from temporary channel interference, incomplete link-layer retransmissions, or physical-layer quality fluctuations, rather than true end-to-end congestion or permanent packet loss, traditional TCP mechanisms lack the ability to identify these problems and are prone to misjudgment, leading to unnecessary performance degradation, bandwidth waste, and unstable network behavior.

[0071] In this invention, upon detecting an ACK timeout event, the TCP layer does not immediately trigger retransmission and congestion control procedures. Instead, it proactively queries the link layer (especially the MAC layer) for current status information through a pre-established inter-layer interface module to obtain an accurate assessment of the actual link condition. This strategy transforms the TCP protocol from "passive retransmission" to "intelligent decision-making," enhancing the adaptability and stability of the transport layer in complex network environments.

[0072] Based on the obtained channel state index parameters of the MAC layer, the TCP layer can evaluate the channel quality of the MAC layer and obtain the channel quality evaluation result of the MAC layer.

[0073] When the channel quality assessment result is unstable, it can be determined that packet loss may be caused by temporary link degradation. An additional time window should be given to the MAC layer to continue attempting lower-layer retransmissions instead of immediate intervention. This strategy helps reduce redundant end-to-end retransmissions and improves overall link resource utilization, and is particularly suitable for wireless environments with high bit error rates and frequent bursts of interference.

[0074] If the channel quality assessment result is stable, it can be determined that the ACK timeout is more likely a genuine packet loss or anomaly in the end-to-end path. In this case, TCP will immediately trigger packet retransmission and simultaneously initiate congestion control mechanisms, such as reducing the congestion window, re-entering the slow start or fast recovery process, to ensure transmission reliability and the timeliness of end-to-end control.

[0075] In some embodiments of the present invention, the step of evaluating the channel quality of the MAC layer based on the channel state index parameters to obtain the channel quality evaluation result of the MAC layer includes:

[0076] Based on the channel state index parameters, namely the channel SNR, channel RSSI, and channel idle rate of the MAC layer, the channel quality of the MAC layer is evaluated to obtain the channel quality evaluation result of the MAC layer.

[0077] It should be noted that when evaluating the channel quality of the MAC layer based on channel state index parameters, easily obtainable parameters such as the MAC layer's signal-to-noise ratio (SNR), received signal strength index (RSSI), and channel idle rate can also be combined to evaluate the MAC layer's channel quality and obtain the MAC layer's channel quality evaluation results.

[0078] In some embodiments of the present invention, the evaluation of the channel quality of the MAC layer based on the channel state index parameters, the channel SNR, channel RSSI, and channel idle rate of the MAC layer, to obtain the channel quality evaluation result of the MAC layer, includes:

[0079] The channel quality result of the MAC layer is unstable if any of the following conditions are not met, and stable if all of the following conditions are met:

[0080] (1) The average number of retransmissions is less than the first value (e.g., 1.25).

[0081] (2) The success rate of sending is greater than the second value (e.g., 85%).

[0082] (3) The instantaneous packet loss rate is less than the third value (e.g., 10%).

[0083] (4) The trend of round-trip time delay is stable or decreasing.

[0084] (5) The transmission rate changes steadily or increases.

[0085] (6) The channel SNR is greater than the fourth value (e.g., 20).

[0086] (7) The channel RSSI is greater than the fifth value (e.g., -90).

[0087] (8) The channel idle rate is greater than the sixth value (e.g., 20%).

[0088] In some embodiments of the present invention, the method further includes:

[0089] Based on the average RTT, RTT standard deviation, average number of retransmissions, average delay of ACK return, packet loss rate, and frequency of duplicate ACKs of data frames in the MAC layer during the target time period, the average SNR and average RSSI of the MAC layer during the target time period, the current congestion window size of the TCP layer, the maximum number of retransmissions of data frames in the MAC layer, the RTO baseline value of the TCP layer, the congestion window growth mode, and the fast retransmission enabled status are adjusted.

[0090] It should be noted that, in order to further improve the data transmission performance of the wireless communication system, the invention can also be adjusted based on the average RTT, RTT standard deviation, average number of retransmissions, average delay of ACK return, packet loss rate, and frequency of duplicate ACKs of data frames in the MAC layer within the target time period, the average SNR and average RSSI of the MAC layer within the target time period, the current congestion window size of the TCP layer, the maximum number of retransmissions of data frames in the MAC layer, the retransmission timeout (RTO) baseline value of the TCP layer, the congestion window growth mode, and the fast retransmission enabled status.

[0091] Traditional RTO typically relies on RTT estimation and error tolerance windows. However, in wireless environments, RTT fluctuates dramatically, and retransmissions increase latency, potentially leading to frequent misjudgments of packet loss using traditional estimation methods. By introducing link-layer feedback, TCP can dynamically calibrate RTO based on dimensions such as transmission delay, retransmission behavior, and ACK response time fed back from the MAC layer. For example, RTO can be appropriately extended when link quality is poor to tolerate short-term fluctuations, while RTO can be appropriately tightened when the channel is stable to improve response speed.

[0092] In some embodiments of the present invention, the adjustment based on the average RTT, RTT standard deviation, average retransmission count, average ACK return delay, packet loss rate, and duplicate ACK frequency of data frames within the MAC layer during the target time period, the average SNR and average RSSI of the MAC layer during the target time period, the current congestion window size of the TCP layer, the maximum retransmission count of data frames within the MAC layer, the RTO baseline value of the TCP layer, the congestion window growth mode, and the fast retransmission enabled status includes:

[0093] The average RTT, RTT standard deviation, average retransmission count, average ACK return delay, packet loss rate, and duplicate ACK frequency of data frames in the MAC layer during the target time period, the average SNR and average RSSI of the MAC layer during the target time period, and the current congestion window size of the TCP layer are used as inputs to the policy adjustment model. The maximum retransmission count of data frames in the MAC layer, the RTO baseline value of the TCP layer, the congestion window growth mode, and the fast retransmission enabled status are obtained from the output of the policy adjustment model.

[0094] The policy adjustment model is trained on the XGBoost model based on sample data carrying policy labels.

[0095] It should be noted that when adjusting the maximum number of retransmissions of data frames within the MAC layer, the RTO baseline value of the TCP layer, the congestion window growth mode, and the fast retransmission enabled state, specific adjustments can be made using the XGBoost model. This model has good generalization ability, fast training / inference speed, and can handle requirements such as missing values ​​and feature importance ranking.

[0096] In some embodiments of the present invention, the sample data is obtained by conducting data communication tests under different channel quality, bandwidth and interference modes.

[0097] It should be noted that during the training of the policy adjustment model, a large number of communication scenarios (such as data communication under different channel quality, bandwidth, and interference modes) can be run in the experimental environment to record various link states and network performance indicators (throughput, average RTT, number of retransmissions, etc.) after policy adjustment. The policy with the best performance can be used as a label for supervised learning training.

[0098] This invention improves data transmission performance in wireless environments through effective collaboration between the TCP layer and the MAC layer.

[0099] To better implement the TCP layer timeout retransmission optimization method in this embodiment of the invention, based on the TCP layer timeout retransmission optimization method, the corresponding method is as follows: Figure 3 As shown, this embodiment of the invention also provides a TCP layer timeout retransmission optimization device. The TCP layer timeout retransmission optimization device 300 includes:

[0100] The acquisition module 301 is used to acquire the transmission result information of each data frame in the MAC layer, and determine the channel state index parameters of the MAC layer within the target time period based on the transmission result information.

[0101] The determination module 302 is used to determine the retransmission strategy of the TCP layer based on the channel state index parameters after the TCP layer detects an ACK timeout event.

[0102] The target time period is the first time period before the TCP layer detects the ACK timeout event. The transmission result information includes the initial transmission timestamp, retransmission count, successful transmission status, and ACK return time. The channel state index parameters include the average retransmission count, successful transmission rate, instantaneous packet loss rate, round-trip delay trend, and transmission rate trend.

[0103] The TCP layer timeout retransmission optimization device 300 provided in the above embodiments can implement the technical solutions described in the above TCP layer timeout retransmission optimization method embodiments. The specific implementation principles of each module or unit can be found in the corresponding content in the above TCP layer timeout retransmission optimization method embodiments, which will not be repeated here.

[0104] like Figure 4 As shown, the present invention also provides a wireless access device 400. The wireless access device 400 includes a processor 401, a memory 402, and a display 403. Figure 4 Only some components of the wireless access device 400 are shown, but it should be understood that it is not required to implement all of the components shown, and more or fewer components may be implemented instead.

[0105] In some embodiments, processor 401 may be a central processing unit (CPU), microprocessor, or other data processing chip, used to run program code stored in memory 402 or process data, such as the magnetic resonance image optimization method of the present invention.

[0106] In some embodiments, processor 401 may be a single server or a group of servers. The server group may be centralized or distributed. In some embodiments, processor 401 may be local or remote. In some embodiments, processor 401 may be implemented on a cloud platform. In one embodiment, the cloud platform may include a private cloud, public cloud, hybrid cloud, community cloud, distributed cloud, internal cloud, multi-cloud, etc., or any combination thereof.

[0107] In some embodiments, memory 402 may be an internal storage unit of the wireless access device 400, such as a hard disk or memory of the wireless access device 400. In other embodiments, memory 402 may also be an external storage device of the wireless access device 400, such as a plug-in hard disk, smart media card (SMC), secure digital (SD) card, flash card, etc., provided on the wireless access device 400.

[0108] Furthermore, the memory 402 may include both internal storage units of the wireless access device 400 and external storage devices. The memory 402 is used to store application software and various types of data installed on the wireless access device 400.

[0109] In some embodiments, display 403 may be an LED display, a liquid crystal display, a touch-sensitive liquid crystal display, or an organic light-emitting diode (OLED) touchscreen. Display 403 is used to display information from the wireless access device 400 and to display a visual user interface. Components 401-403 of the wireless access device 400 communicate with each other via a system bus.

[0110] In one embodiment, when processor 401 executes the TCP layer timeout retransmission optimization program in memory 402, the following steps can be implemented:

[0111] Obtain the transmission result information of each data frame in the MAC layer, and determine the channel state index parameters of the MAC layer within the target time period based on the transmission result information;

[0112] After the TCP layer detects an ACK timeout event, it determines the retransmission strategy of the TCP layer based on the channel state index parameters.

[0113] The target time period is the first time period before the TCP layer detects the ACK timeout event. The transmission result information includes the initial transmission timestamp, retransmission count, successful transmission status, and ACK return time. The channel state index parameters include the average retransmission count, successful transmission rate, instantaneous packet loss rate, round-trip delay trend, and transmission rate trend.

[0114] It should be understood that when the processor 401 executes the TCP layer timeout retransmission optimization program in the memory 402, in addition to the functions mentioned above, it can also implement other functions, as can be found in the description of the corresponding method embodiments above.

[0115] Furthermore, the embodiments of the present invention do not specifically limit the type of wireless access device 400 mentioned. The wireless access device 400 can be various types of APs, base stations of various sizes, or other devices with wireless access functions, etc.

[0116] Accordingly, this application also provides a computer-readable storage medium for storing a computer-readable program or instruction. When the program or instruction is executed by a processor, it can implement the steps or functions of the TCP layer timeout retransmission optimization method provided in the above-described method embodiments.

[0117] Those skilled in the art will understand that all or part of the processes of the methods described in the above embodiments can be implemented by a computer program instructing related hardware (such as a processor, controller, etc.), and the computer program can be stored in a computer-readable storage medium. The computer-readable storage medium may be a disk, optical disk, read-only memory, or random access memory, etc.

[0118] The TCP layer timeout retransmission optimization method and apparatus provided by the present invention have been described in detail above. Specific examples have been used to illustrate the principle and implementation of the present invention. The description of the above embodiments is only for the purpose of helping to understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation and application scope based on the idea of ​​the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A TCP layer timeout retransmission optimization method, characterized in that, include: Obtain the transmission result information of each data frame in the MAC layer, and determine the channel state index parameters of the MAC layer within the target time period based on the transmission result information; After the TCP layer detects an ACK timeout event, it determines the retransmission strategy of the TCP layer based on the channel state index parameters. The target time period is the first time period before the TCP layer detects the ACK timeout event. The transmission result information includes the initial transmission timestamp, retransmission count, successful transmission status, and ACK return time. The channel state index parameters include the average retransmission count, successful transmission rate, instantaneous packet loss rate, round-trip delay trend, and transmission rate trend. The step of determining the retransmission strategy of the TCP layer based on the channel state index parameters includes: The channel quality of the MAC layer is evaluated based on the channel state index parameters to obtain the channel quality evaluation result of the MAC layer. If the channel quality evaluation result is unstable, the TCP layer retransmission mechanism will be initiated after the second time period. If the channel quality evaluation result is stable, immediately initiate the retransmission of the data frame corresponding to the ACK timeout event, and initiate the congestion control mechanism of the TCP layer. The process of evaluating the channel quality of the MAC layer based on the channel state index parameters to obtain the channel quality evaluation result of the MAC layer includes: Based on the channel state index parameters, the channel SNR, channel RSSI and channel idle rate of the MAC layer, the channel quality of the MAC layer is evaluated to obtain the channel quality evaluation result of the MAC layer. The channel quality of the MAC layer is evaluated based on the channel state index parameters, namely the channel SNR, channel RSSI, and channel idle rate of the MAC layer, to obtain the channel quality evaluation result of the MAC layer, including: The channel quality result of the MAC layer is unstable if any of the following conditions are not met, and stable if all of the following conditions are met: The average number of retransmissions is less than the first value; The success rate of sending the message is greater than the second value; The instantaneous packet loss rate is less than the third value; The trend of round-trip time delay is stable or decreasing; The transmission rate shows a stable or increasing trend; The channel SNR is greater than the fourth value; The channel RSSI is greater than the fifth value; The channel idle rate is greater than the sixth value.

2. The TCP layer timeout retransmission optimization method according to claim 1, characterized in that, The method further includes: Based on the average RTT, RTT standard deviation, average number of retransmissions, average delay of ACK return, packet loss rate, and frequency of duplicate ACKs of data frames in the MAC layer during the target time period, the average SNR and average RSSI of the MAC layer during the target time period, the current congestion window size of the TCP layer, the maximum number of retransmissions of data frames in the MAC layer, the RTO baseline value of the TCP layer, the congestion window growth mode, and the fast retransmission enabled status are adjusted.

3. The TCP layer timeout retransmission optimization method according to claim 2, characterized in that, The adjustment of the following parameters based on the average RTT, RTT standard deviation, average retransmission count, average ACK return delay, packet loss rate, and frequency of duplicate ACKs for data frames within the MAC layer during the target time period; the average SNR and average RSSI of the MAC layer during the target time period; the current congestion window size of the TCP layer; the maximum retransmission count for data frames within the MAC layer; and the TCP layer's RTO baseline, congestion window growth mode, and fast retransmission enabled status includes: The average RTT, RTT standard deviation, average retransmission count, average ACK return delay, packet loss rate, and duplicate ACK frequency of data frames in the MAC layer during the target time period, the average SNR and average RSSI of the MAC layer during the target time period, and the current congestion window size of the TCP layer are used as inputs to the policy adjustment model. The maximum retransmission count of data frames in the MAC layer, the RTO baseline value of the TCP layer, the congestion window growth mode, and the fast retransmission enabled status are obtained from the output of the policy adjustment model. The policy adjustment model is trained on the XGBoost model based on sample data carrying policy labels.

4. The TCP layer timeout retransmission optimization method according to claim 3, characterized in that, The sample data was obtained through data communication tests under different channel quality, bandwidth, and interference modes.

5. A TCP layer timeout retransmission optimization device, characterized in that, include: The acquisition module is used to acquire the transmission result information of each data frame in the MAC layer, and determine the channel state index parameters of the MAC layer within the target time period based on the transmission result information. The determination module is used to determine the retransmission strategy of the TCP layer based on the channel state index parameters after the TCP layer detects an ACK timeout event. The target time period is the first time period before the TCP layer detects the ACK timeout event. The transmission result information includes the initial transmission timestamp, retransmission count, successful transmission status, and ACK return time. The channel state index parameters include the average retransmission count, successful transmission rate, instantaneous packet loss rate, round-trip delay trend, and transmission rate trend. The step of determining the retransmission strategy of the TCP layer based on the channel state index parameters includes: The channel quality of the MAC layer is evaluated based on the channel state index parameters to obtain the channel quality evaluation result of the MAC layer. If the channel quality evaluation result is unstable, the TCP layer retransmission mechanism will be initiated after the second time period. If the channel quality evaluation result is stable, immediately initiate the retransmission of the data frame corresponding to the ACK timeout event, and initiate the congestion control mechanism of the TCP layer. The process of evaluating the channel quality of the MAC layer based on the channel state index parameters to obtain the channel quality evaluation result of the MAC layer includes: Based on the channel state index parameters, the channel SNR, channel RSSI and channel idle rate of the MAC layer, the channel quality of the MAC layer is evaluated to obtain the channel quality evaluation result of the MAC layer. The channel quality of the MAC layer is evaluated based on the channel state index parameters, namely the channel SNR, channel RSSI, and channel idle rate of the MAC layer, to obtain the channel quality evaluation result of the MAC layer, including: The channel quality result of the MAC layer is unstable if any of the following conditions are not met, and stable if all of the following conditions are met: The average number of retransmissions is less than the first value; The success rate of sending the message is greater than the second value; The instantaneous packet loss rate is less than the third value; The trend of round-trip time delay is stable or decreasing; The transmission rate shows a stable or increasing trend; The channel SNR is greater than the fourth value; The channel RSSI is greater than the fifth value; The channel idle rate is greater than the sixth value.

6. A wireless access device, characterized in that, Including memory and processor, among which, The memory is used to store programs; The processor, coupled to the memory, is used to execute the program stored in the memory to implement the steps in the TCP layer timeout retransmission optimization method according to any one of claims 1 to 4.

7. A computer-readable storage medium, characterized in that, Used to store computer-readable programs or instructions, which, when executed by a processor, can implement the steps in the TCP layer timeout retransmission optimization method described in any one of claims 1 to 4.

Images