Method and device for preventing STA (Station) from dropping, storage medium and AP (Access Point)

Abstract

The embodiment of the invention discloses a method and device for preventing an STA from being disconnected, a storage medium and an AP, and relates to the field of wireless communication. The method comprises the following steps that: an AP (Access Point) firstly acquires the monitoring intervals of all STAs (Station) in a low-power-consumption mode, determines the maximum monitoring interval and calculates the integral multiple LI of the maximum monitoring interval and a Beacon interval; setting an aggregation constraint interval length of a basic time interval formed by LI Beacon intervals; and when a trigger signal is detected, sequentially setting an aggregation frame sending interval, a block acknowledgement frame receiving interval and a Beacon frame sending interval in the LI basic time intervals of the aggregation constraint interval, and limiting the interval length between the end of the aggregation frame sending interval and the start of the Beacon frame sending interval. And after data transmission is completed, waiting for a next trigger signal appearing according to a Tlos / n period. According to the method, the problem that the STA in the low-power-consumption mode is disconnected due to the fact that the sending duration of the aggregation frame is too long is effectively avoided, and the stability of data transmission and the communication continuity are guaranteed.

Description

Technical Field

[0001] This application relates to the field of wireless communication, and in particular, to a method, device, storage medium, and AP for preventing an STA from dropping the line. Background Art

[0002] In a network architecture as shown in Figure 1A , an AP (Access Point) serves as the core control device of the network and is responsible for data interaction with each STA (Station). The STA in the normal mode (STA_w) is always in the working state and can respond to the data transmission request of the AP at any time, and there is basically no risk of dropping the line. While the STA in the low-power mode (STA_s) adopts a periodic listening working method to save power, and only wakes up to listen to the channel within a specific listening window to receive data or control information from the AP.

[0003] In the data transmission timing sequence between the AP and the STA as shown in Figure 1B , the AP will send buffered frames to each STA. If there is no data frame to be sent to a certain STA for a long time, the AP will send an empty packet frame to it to maintain the connection with the STA and prevent it from dropping the line due to not receiving data for a long time. For STA_s, its data reception process depends on listening to the Beacon frame. When STA_s successfully listens and receives the Beacon frame, it will further check the TIM (Traffic Indication Map) information in the Beacon frame. If the TIM information indicates that there is a buffered frame of STA_s in the AP, STA_s will continue to receive the buffered frame after receiving the Beacon frame, and reply with a response (ACK frame) to the AP after the reception is completed, and then enter the sleep state. After receiving the response, the AP will maintain the connection with STA_s. However, if STA_s fails to listen (fails to receive the Beacon frame), or although the listening is successful but the TIM information in the Beacon frame does not indicate that there is a buffered frame of STA_s, STA_s will directly re-enter the sleep state and wait for the next listening window to arrive.

[0004] In practical applications, the AP may be connected to STA_w and STA_s at the same time. In the existing technical solutions, there is no effective limiting mechanism for the duration of the aggregated frame (A-MPDU, Aggregated MAC Protocol Data Unit) sent to STA_w. This results in the situation that the transmission duration of the aggregated frame may be too long during the actual data transmission process.

[0005] Since the transmission of Beacon frames has strict time requirements in wireless LANs, the transmission time must follow a specific time interval and timing arrangement to ensure that each STA in the network can accurately synchronize and obtain network information. When the aggregation frame transmission time is too long, it will inevitably occupy the time point when the Beacon frame should be sent, thereby delaying the transmission of the Beacon frame.

[0006] For STA_s in low power mode, the size of its listening window is strictly limited, which is the basic requirement of low power mode for STA_s hardware design and power management. The delay in sending Beacon frames will cause STA_s to fail to successfully receive Beacon frames within the predetermined listening window, that is, listening failure. If STA_s fails to listen for many consecutive times, according to the offline judgment mechanism in low power mode, when the preset offline duration threshold T_lost is exceeded, the STA_s is likely to be judged as offline by the AP, thereby disconnecting from the AP. This will not only affect the normal communication of STA_s, but may also cause network performance to degrade and reduce user experience.

[0007] Therefore, how to effectively solve the problem in the prior art that the Beacon frame transmission is delayed due to the long transmission time of the aggregation frame, which in turn causes the STA in low power mode to be disconnected, has become a technical problem that needs to be urgently solved in the current field of wireless LAN technology. Summary of the invention

[0008] The embodiments of the present application provide a method, device, storage medium and AP for preventing STA from disconnecting, which can solve the problem in the prior art that the transmission length of the aggregated frame is too large, causing the STA in the low power consumption mode to be easily disconnected. The technical solution is as follows:

[0009] In a first aspect, an embodiment of the present application provides a method for preventing a STA from being disconnected, the method comprising:

[0010] Obtain the listening intervals of all STAs in low power consumption mode, determine the maximum listening interval among the obtained listening intervals, and calculate the integer multiple LI between the maximum listening interval and the Beacon interval;

[0011] Set the length of the aggregation constraint interval; wherein the aggregation constraint interval consists of LI basic time intervals, and the length of each basic time interval is equal to one Beacon interval;

[0012] When the current trigger signal is detected to arrive, data is transmitted within LI basic time intervals in the aggregation constraint interval; wherein, each basic time interval is sequentially provided with: an aggregation frame transmission interval, a block acknowledgment frame reception interval, and a Beacon frame transmission interval, the aggregation frame transmission interval is used to transmit an aggregation frame, the block acknowledgment frame reception interval is used to receive the block acknowledgment frame of the aggregation frame, and the Beacon frame transmission interval is used to transmit a Beacon frame; the length between the end moment of the aggregation frame transmission interval and the start moment of the Beacon frame transmission interval is set as T_left, satisfying T_left≥(the length of the block acknowledgment frame reception interval + 2*SIFS);

[0013] After the data transmission within the aggregation constraint interval is completed, wait for the next trigger signal; wherein, the occurrence period of the trigger signal is equal to Tloss / n, n is an integer greater than 1, and Tloss represents the STA disconnection duration.

[0014] In a second aspect, an embodiment of the present application provides a device for preventing STA disconnection, and the device includes:

[0015] An obtaining unit, configured to obtain the listening intervals of all STAs in the low power consumption mode, determine the maximum listening interval among the obtained listening intervals, and calculate the integer multiple LI between the maximum listening interval and the Beacon interval;

[0016] A setting unit, configured to set the length of the aggregation constraint interval; wherein, the aggregation constraint interval is composed of LI basic time intervals, and the length of each basic time interval is equal to a Beacon interval;

[0017] A trigger unit, configured to, when the current trigger signal is detected to arrive, transmit data within LI basic time intervals in the aggregation constraint interval; wherein, each basic time interval is sequentially provided with: an aggregation frame transmission interval, a block acknowledgment frame reception interval, and a Beacon frame transmission interval, the aggregation frame transmission interval is used to transmit an aggregation frame, the block acknowledgment frame reception interval is used to receive the block acknowledgment frame of the aggregation frame, and the Beacon frame transmission interval is used to transmit a Beacon frame; the length between the end moment of the aggregation frame transmission interval and the start moment of the Beacon frame transmission interval is set as T_left, satisfying T_left≥(the length of the block acknowledgment frame reception interval + 2*SIFS);

[0018] A waiting unit, configured to, after the data transmission within the aggregation constraint interval is completed, wait for the next trigger signal; wherein, the occurrence period of the trigger signal is equal to Tloss / n, n is an integer greater than 1, and Tloss represents the STA disconnection duration.

[0019] In a third aspect, an embodiment of the present application provides a computer storage medium storing multiple instructions adapted to be loaded and executed by a processor to perform the above method steps.

[0020] In a fourth aspect, an embodiment of the present application provides an AP, which may include: a processor and a memory; wherein, the memory stores a computer program adapted to be loaded and executed by the processor to perform the above method steps.

[0021] The beneficial effects brought by the technical solutions provided by some embodiments of the present application at least include:

[0022] By obtaining the listening interval of the STA in the low-power mode to determine the integer multiple relationship LI between the maximum listening interval and the BEACON interval, an aggregation constraint interval composed of LI BEACON intervals is set as the basic time interval, and the aggregation frame transmission, block acknowledgment frame reception, and BEACON frame transmission intervals are reasonably planned within each basic time interval. At the same time, the interval length between the end moment of the aggregation frame transmission interval and the start moment of the BEACON frame transmission interval is restricted to ensure the timely transmission of the Beacon frame. Combined with the setting of the trigger signal appearance period, there is sufficient time to transmit data within the STA disconnection duration, effectively solving the problem in the background technology that the STA in the low-power mode is prone to disconnection due to the too long aggregation frame transmission duration, and ensuring the high efficiency, stability, and communication continuity of data transmission in the low-power mode. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] To more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0024] Figure 1A is a network architecture diagram provided by an embodiment of the present application;

[0025] Figure 1B is a timing diagram of data transmission between an AP and an STA provided in the prior art

[0026] Figure 2 is a flowchart of the method for preventing STA disconnection provided by an embodiment of the present application;

[0027] Figure 3A is a schematic diagram of the aggregation constraint interval provided by an embodiment of the present application;

[0028] Figure 3BIt is a distribution schematic diagram of the aggregation frame transmission interval, block acknowledgment frame reception interval, and Beacon frame transmission interval within the aggregation constraint interval provided by an embodiment of the present application;

[0029] Figure 4 It is a structural schematic diagram of a device for preventing STA disconnection provided by the present application;

[0030] Figure 5 It is a structural schematic diagram of an AP provided by the present application. Detailed implementation manners

[0031] To make the objectives, technical solutions, and advantages of the present application clearer, the following will further describe the embodiments of the present application in detail with reference to the accompanying drawings.

[0032] Please refer to Figure 2 , which is a flowchart of a method for preventing STA disconnection provided by an embodiment of the present application. As Figure 2 shown, the method of the embodiment of the present application may include the following steps:

[0033] S201. Obtain the listening intervals of all STAs in the low-power mode, determine the maximum listening interval among the obtained listening intervals, and calculate the integer multiple LI between the maximum listening interval and the Beacon interval.

[0034] Among them, in a wireless local area network (WLAN) environment, an access point (AP) manages multiple stations (STAs), and these STAs may be in a normal working mode or a low-power mode. The low-power mode is a strategy adopted by STAs to save electrical energy. In this mode, STAs will periodically wake up from the sleep state to listen to the channel and receive data or control information from the AP. The listening interval, that is, the time interval between two wake-ups of the STA, is a key parameter in the low-power mode.

[0035] The AP needs to obtain the listening intervals of all STAs in the low-power mode through the following two main methods: First, when establishing a communication connection with the STA, the STA will actively report its listening interval to the AP; Second, during subsequent communication processes, the AP can dynamically obtain the listening interval of the STA according to protocol requirements or actual needs. Once the listening intervals of all STAs are obtained, the AP will compare and analyze them to determine the maximum listening interval.

[0036] Next, the AP needs to calculate the multiple relationship between this maximum listening interval and the Beacon interval, that is, LI. The Beacon interval is the fixed time interval at which the AP sends Beacon frames, and the Beacon frames contain crucial information such as network identification and time synchronization. The purpose of calculating LI is to enable the AP to reasonably arrange the length of the aggregation constraint interval based on this multiple relationship during subsequent data transmission, thereby ensuring the efficiency and stability of data transmission.

[0037] For example: Suppose the AP manages three STAs in the low-power mode, and their listening intervals are 100 ms, 200 ms, and 300 ms respectively. After the AP obtains these listening intervals through the above method and compares them, the maximum listening interval is found to be 300 ms. If the preset Beacon interval is 100 ms, then the maximum listening interval of 300 ms is 3 times the Beacon interval, that is, LI = 3.

[0038] In some possible embodiments of the present application, when it is detected that an STA in the low-power mode has been updated, the listening intervals of all STAs in the low-power mode after the update are obtained; the AP obtains the listening interval of each STA when it connects, and at the same time, the STA also notifies the AP of the listening interval before entering the low-power mode. If the STA exits the low-power mode or modifies its listening interval, the AP also needs to synchronously update LI.

[0039] Among them, when the STA establishes an association (Association) or re-association (Reassociation) with the AP, the AP obtains the initial listening interval (Listen Interval) of the STA through the Capability Information field of the Association Request or Reassociation Request frame. In addition, if the STA has entered the low-power mode (such as the PS-Poll mode) before association, it needs to explicitly declare the listening interval through the Power Management sub-field during the association phase.

[0040] When the STA switches from the normal mode to the low-power mode (or vice versa), it needs to notify the AP through the Power Save status change. When the STA dynamically modifies the listening interval in the low-power mode (such as due to battery power change or service priority adjustment), it needs to trigger an update through an Action frame or a Management Action sub-type. The AP can actively initiate a Power Save Query request to require the STA to report the current listening interval.

[0041] The STA sends the updated listen interval to the AP through the Power Management subfield or the newly added Listen Interval Update frame (requiring protocol extension). If the STA exits the low-power mode, it needs to clear the Power Save flag in the Association Response or Reassociation Response and reset the listen interval to 0 (indicating continuous listening). After receiving the update, the AP confirms the update result through the ACK frame or the Status Code field. If the update fails (such as invalid parameters), the AP terminates the association through the Deauthentication or Disassociation frame and requests the STA to renegotiate. After receiving the listen interval updates from all STAs, the AP needs to recalculate the integer multiple relationship LI between the maximum listen interval (LI_max) and the BEACON interval.

[0042] S202. Set the length of the aggregation constraint interval.

[0043] Among them, the aggregation constraint interval consists of LI basic time intervals, and the length of each basic time interval is equal to one Beacon interval. After determining LI, the AP further sets the length of the aggregation constraint interval. The aggregation constraint interval is a time interval specifically set by the AP to achieve efficient data transmission in the low-power mode. It consists of LI basic time intervals. The length of each basic time interval is exactly equal to one Beacon interval. Such a design aims to ensure that within the aggregation constraint interval, the AP can strictly follow the transmission period of the Beacon frame to reasonably arrange the transmission of aggregation frames and Beacon frames, thereby effectively preventing the STA in the low-power mode from dropping the line due to not receiving data for a long time.

[0044] When setting the length of the aggregation constraint interval, the AP needs to comprehensively consider multiple factors, including the listen interval of the STA, the Beacon interval, the data transmission rate, and efficiency, etc. By carefully adjusting the length of the aggregation constraint interval, the AP can ensure that the STA can receive data in a timely manner while maximizing the data transmission efficiency.

[0045] Illustrative example: Taking the example in S201 as an example, if LI = 3 and the Beacon interval is 100 ms, then the length of the aggregation constraint interval is the sum of 3 Beacon intervals, that is, 300 ms. This aggregation constraint interval consists of 3 basic time intervals, and the length of each basic time interval is 100 ms.

[0046] S203. When detecting the arrival of the current trigger signal, transmit data within the LI basic time intervals of the aggregation constraint interval.

[0047] Among them, each basic time interval is sequentially set with: an aggregated frame transmission interval, a block acknowledgment frame reception interval, and a Beacon frame transmission interval. The aggregated frame transmission interval is used to transmit aggregated frames. The block acknowledgment frame reception interval is used to receive the block acknowledgment frames of the aggregated frames. The Beacon frame transmission interval is used to transmit Beacon frames. The length between the end moment of the aggregated frame transmission interval and the start moment of the Beacon frame transmission interval is set as T_left, satisfying T_left ≥ (the length of the block acknowledgment frame reception interval + 2 * SIFS).

[0048] When the AP detects the arrival of the current trigger signal, it will initiate the data transmission process within LI basic time intervals in the aggregation constraint interval. The trigger signal is a signal specially sent by the AP to initiate data transmission, and its occurrence period is set as Tloss / n, where Tloss represents the duration of STA disconnection, and n is an integer greater than 1. By carefully setting the occurrence period of the trigger signal, the AP can ensure that there is sufficient time for data transmission before the STA disconnects, thus ensuring the continuity of communication.

[0049] Within each basic time interval, the AP will sequentially set an aggregated frame transmission interval, a block acknowledgment frame reception interval, and a Beacon frame transmission interval. The aggregated frame transmission interval is used for the AP to send aggregated frames to the STA. The aggregated frame contains multiple data frames, and this design can significantly improve the data transmission efficiency. The block acknowledgment frame reception interval is used for the AP to receive the block acknowledgment frames of the aggregated frames from the STA. The block acknowledgment frame can confirm whether the STA has successfully received the aggregated frame, thus ensuring the accuracy of data transmission. The Beacon frame transmission interval is used for the AP to send Beacon frames to maintain the normal operation and synchronization of the network.

[0050] In addition, the length between the end moment of the aggregated frame transmission interval and the start moment of the Beacon frame transmission interval is set as T_left. This length must satisfy T_left ≥ (the length of the block acknowledgment frame reception interval + 2 * SIFS). SIFS is the Short Inter-Frame Space, which is used to ensure that there is sufficient interval time between the transmissions of different frames, thus avoiding frame collisions and transmission errors. The purpose of restricting the length of T_left is to ensure that the transmitted Beacon frames will not be postponed, so as to ensure that LI Beacon frames can be sent on time after the current trigger signal. In this way, all STAs in the low-power mode can at least hear a Beacon frame after generating a trigger signal, thereby effectively avoiding the disconnection of STAs in the low-power mode.

[0051] For example: Assume that the occurrence period of the trigger signal is Tloss / 2, and Tloss is 600 ms, then the occurrence period of the trigger signal is 300 ms. Within the aggregation constraint interval (with a length of 300 ms), the AP will sequentially set the aggregation frame transmission interval, the block acknowledgment frame reception interval, and the Beacon frame transmission interval within each basic time interval (with a length of 100 ms). If the length of the block acknowledgment frame reception interval is 20 ms and the SIFS is 10 ms, then the length of T_left needs to be at least 40 ms (20 ms + 2 * 10 ms) to ensure that the transmission of the Beacon frame will not be postponed due to an overly long aggregation frame during its transmission process.

[0052] In one or more possible embodiments, the aggregation frame includes multiple MPDUs, and the transmission duration of each MPDU is calculated according to the data volume and modulation and coding scheme of the MPDU; the reception duration of the block acknowledgment frame is calculated according to the data volume and modulation and coding scheme.

[0053] Specifically, the dynamic calculation process of the MPDU transmission duration.

[0054] Input parameters: Data volume (Payload Size): The number of payload bytes carried by each MPDU (such as an Ethernet frame or a MAC service data unit). Modulation and coding scheme (MCS): The modulation and coding rate dynamically selected by the AP according to the channel quality (such as SNR, RSSI) (such as MCS 0 - 11 in 802.11ax).

[0055] The AP queries the physical layer transmission rate specified by the protocol according to the current MCS index (such as the 80 MHz bandwidth rate corresponding to MCS 7 is 6.5 Mbps).

[0056] The transmission duration of the MPDU (T_MPDU) is determined by the following formula:

[0057] T_MPDU = (PHY Rate * Payload Size + MAC Header + FCS) / PHYrate + PHY Overhead

[0058] PHY Rate * Payload Size, MAC Header, and FCS respectively represent: the sizes of the payload, the MAC header (such as 28 bytes), and the FCS check (4 bytes).

[0059] PHYrate represents the physical layer rate, which is jointly determined by the MCS and the bandwidth (such as the rate of MCS 7 under 80 MHz bandwidth is 6.5 Mbps).

[0060] PHY Overhead represents the physical layer overhead (such as PLCP preamble, SIG field), which is usually a fixed value (e.g., 20 - 40 μs in 802.11ax).

[0061] The AP dynamically adjusts the MCS for different STAs according to the channel conditions, ensuring that the MPDU reduces the rate when the channel quality is poor (e.g., switches to MCS 0), and increases the rate when the channel quality is excellent (e.g., switches to MCS11).

[0062] Calculation of the reception duration of the BlockACK frame.

[0063] Input parameters: BlockACK data volume: The confirmation information contains multiple TIDs (Traffic Identifiers), usually with a fixed length (e.g., the BlockACK frame length is 64 bytes in 802.11ax). Modulation and Coding Scheme (MCS): The MCS used by the STA to feedback the Block ACK, which may be different from the MCS used by the AP to send the MPDU (the difference between the uplink and downlink channels needs to be considered).

[0064] The STA selects the MCS of the BlockACK according to the downlink channel quality (e.g., MCS 4), and the AP needs to calculate the reception duration based on this MCS.

[0065] The reception duration of the BlockACK (T_BlockACK) is determined by the following formula:

[0066] T_BlockACK = Block ACK Size / STA_PHY_Rate + SIFS + Propagation Delay

[0067] STA_PHY_Rate represents the physical layer rate at which the STA feedbacks the BlockACK.

[0068] SIFS represents the Short Inter - Frame Space (e.g., 16 μs in 802.11ax), ensuring that the STA sends the BlockACK immediately after completing the reception of the MPDU.

[0069] Propagation Delay represents the signal propagation delay (usually at the nanosecond level and can also be ignored).

[0070] The AP ensures that the sum of T_MPDU and T_BlockACK does not exceed the transmission window of the aggregated frame (such as the constraint interval defined by the NAV or trigger signal), to avoid the STA timing out due to excessive delay.

[0071] Among them, in the aggregation constraint interval, when the AP generates an aggregated frame and adds one MPDU each time, it must ensure that after adding this MPDU, the duration T_left from the end time point of this aggregated frame to the transmission time point of the next Beacon frame satisfies T_left >= (SIFS + RX BA duration + SIFS). If it cannot be satisfied, this MPDU will not be added to the aggregated frame.

[0072] The aggregation constraint interval refers to the remaining time window that the AP must satisfy when generating an aggregated frame (A-MPDU), that is, the duration (denoted as T_left) from the end time point of the current aggregated frame to the transmission time point of the next Beacon frame. Ensure that after the transmission of the aggregated frame is completed, the STA has enough time to receive the BlockACK (BA) and return an acknowledgment, while avoiding conflicts with the transmission of the Beacon frame.

[0073] Each time the AP attempts to add a new MPDU to the aggregated frame, it needs to calculate whether the added T_left satisfies the following inequality: T_left >= (SIFS + T_BA + SIFS).

[0074] The first SIFS: Short Interframe Space, which is used to separate the data frame and the acknowledgment frame (such as 16 μs in 802.11ax). T_BA: The reception duration of the BlockACK (determined by the physical layer rate and data volume of the STA's feedback of the BlockACK, see the above calculation formula for details). The second SIFS is used to separate the BlockACK from the transmission of the subsequent Beacon frame.

[0075] The AP calculates the remaining time according to the cumulative duration (T_aggregated) of the current aggregated frame and the transmission time point (T_next_beacon) of the next Beacon frame: T_left = T_next_beacon - (T_aggregated + T_MPDU_current). T_MPDU_current is the transmission duration of the current MPDU to be added (determined by the data volume and MCS, see the above calculation formula for details). If T_left satisfies the above inequality, the current MPDU is allowed to be added; otherwise, the generation of the aggregated frame is terminated.

[0076] The AP in this embodiment realizes precise timing control in the process of generating the aggregated frame through the aggregation constraint interval and the dynamic addition mechanism of the MPDU. The core lies in:

[0077] Ensure that there is enough time (SIFS + T_BA + SIFS) between the end time point of the aggregated frame and the transmission time point of the Beacon frame. Optimize the number of MPDUs of the aggregated frame in real time according to T_left to balance the transmission efficiency and latency requirements. Through the exception handling mechanism and performance optimization strategy, ensure the stability and efficiency in complex scenarios. This mechanism provides a basic framework for the aggregated frame transmission of future high-density and low-latency WLANs, and can further combine TWT (Target Wake Time) and dynamic bandwidth allocation technologies to improve energy efficiency and throughput.

[0078] S204. After completing the data transmission within the aggregated constraint interval, wait for the next trigger signal.

[0079] Among them, the occurrence period of the trigger signal is equal to Tloss / n, where n is an integer greater than 1, and Tloss represents the STA disconnection duration.

[0080] After completing the data transmission within the aggregated constraint interval, the AP will enter a waiting state and wait for the arrival of the next trigger signal. The occurrence period of the trigger signal is equal to Tloss / n, where n is an integer greater than 1, and Tloss represents the STA disconnection duration. This design ensures that the AP has enough time to transmit data before the STA disconnects, thus maintaining the stability and continuity of communication. When the next trigger signal arrives, the AP will repeat the steps in S203 to start the data transmission process within the new aggregated constraint interval.

[0081] In some embodiments of the present application, the AP generates 2 trigger signals within each T_loss period to ensure that all low-power STAs can hear at least 2 Beacon frames within the T_loss period and maintain the network connection state.

[0082] T_loss is the maximum disconnection duration allowed for the STA, usually at the second level (such as 300 seconds). The Beacon Interval is at the millisecond level (such as 100 ms), and T_loss is 2 to 3 orders of magnitude larger than the Beacon Interval. Therefore, only a very small proportion of the Beacon frame transmission time points need to be constrained to meet the listening requirements. When T_loss is longer or the maximum listening interval is smaller, the AP can increase the number of triggers to 3 to 4 times. Increasing the number of triggers has a minimal negative impact on traffic because the trigger signal only accounts for a very small proportion of the T_loss period (for example, when k = 4, the trigger signal accounts for only 12.5%). The trigger signal is used to start the aggregated data transmission and does not impose constraints on the transmission time points of most Beacon frames, so it will not significantly reduce the aggregation number of the aggregated frames.

[0083] The AP only constrains the transmission time points of a very small proportion of Beacon frames (for example, 2 to 4 times within each T_loss period), and the remaining Beacon frames are sent according to the regular period. Ensure that the low-power STA can hear the Beacon frames at least twice within the T_loss period to avoid disconnection due to not hearing the Beacon frames for a long time. After the trigger signal arrives, the AP preferentially sends the constrained Beacon frames within the subsequent aggregated constraint interval. The remaining Beacon frames are sent according to the regular period and are not affected by the trigger signal to ensure that the traffic of the normal-mode STA is not affected. The AP can maximize the aggregation quantity of the aggregated frames within the unconstrained Beacon frame interval to improve the transmission efficiency. The AP dynamically adjusts the proportion of the constrained Beacon frames according to the service requirements of the STA (such as the proportion of the low-power STA to the normal-mode STA) to ensure the balance between traffic and energy efficiency.

[0084] The present application specifically includes the following beneficial effects:

[0085] By obtaining the listening interval of the low-power mode STA to determine the integer multiple relationship LI between the maximum listening interval and the BEACON interval, an aggregated constraint interval composed of LI BEACON intervals is set as the basic time interval, and within each basic time interval, the aggregated frame transmission, block acknowledgment frame reception, and Beacon frame transmission intervals are reasonably planned. At the same time, the interval length between the end moment of the aggregated frame transmission interval and the start moment of the Beacon frame transmission interval is restricted to ensure that the Beacon frames are sent on time. Combined with the setting of the trigger signal occurrence period, there is sufficient time to transmit data within the STA disconnection duration, effectively solving the problem in the background technology that the low-power mode STA is prone to disconnection due to the too long aggregated frame transmission duration, and ensuring the high efficiency, stability, and communication continuity of data transmission in the low-power mode.

[0086] The following is the device embodiment of the present application, which can be used to execute the method embodiment of the present application. For the details not disclosed in the device embodiment of the present application, please refer to the method embodiment of the present application.

[0087] Please refer to Figure 4 , which shows a schematic structural diagram of a device for preventing STA disconnection provided by an exemplary embodiment of the present application, hereinafter referred to as device 4. This device 4 can be implemented as all or part of the AP through software, hardware, or a combination of both. The device 4 includes: an acquisition unit 401, a setting unit 402, a trigger unit 403, and a waiting unit 404.

[0088] The acquisition unit 401 is used to obtain the listening intervals of all the low-power mode STAs, determine the maximum listening interval among the obtained listening intervals, and calculate the integer multiple LI between the maximum listening interval and the Beacon interval;

[0089] A setting unit 402 is configured to set the length of the aggregation constraint interval; wherein, the aggregation constraint interval consists of LI basic time intervals, and the length of each basic time interval is equal to a Beacon interval;

[0090] A triggering unit 403 is configured to, when detecting the arrival of a current triggering signal, transmit data within the LI basic time intervals of the aggregation constraint interval; wherein, each basic time interval is sequentially provided with: an aggregation frame transmission interval, a block acknowledgment frame reception interval, and a Beacon frame transmission interval. The aggregation frame transmission interval is used to transmit an aggregation frame, the block acknowledgment frame reception interval is used to receive the block acknowledgment frame of the aggregation frame, and the Beacon frame transmission interval is used to transmit a Beacon frame; the length between the end moment of the aggregation frame transmission interval and the start moment of the Beacon frame transmission interval is set to T_left, satisfying T_left≥(the length of the block acknowledgment frame reception interval + 2*SIFS);

[0091] A waiting unit 404 is configured to, after completing the data transmission within the aggregation constraint interval, wait for the next triggering signal; wherein, the occurrence period of the triggering signal is equal to Tloss / n, n is an integer greater than 1, and Tloss represents the STA disconnection duration.

[0092] In one or more possible embodiments, obtaining the listening intervals of all STAs in the low-power mode includes:

[0093] When detecting an update of an STA in the low-power mode, obtaining the listening intervals of all updated STAs in the low-power mode.

[0094] In one or more possible embodiments, n = 2 or 3 or 4.

[0095] In one or more possible embodiments, the aggregation frame includes multiple MPDUs, and the transmission duration of each MPDU is calculated according to the data volume and modulation and coding scheme of the MPDU; the reception duration of the block acknowledgment frame is calculated according to the data volume and modulation and coding scheme.

[0096] In one or more possible embodiments, the transmission duration T_MPDU of the MPDU is calculated according to the following formula:

[0097] T_MPDU = (PHY RatePayload Size + MAC Header + FCS) / PHYrate + PHY Overhead;

[0098] Among them, PHY Rate Payload Size represents the size of the payload, MAC Header represents the size of the MAC header, and FCS represents the size of the FCS check field value; PHY rate represents the physical layer rate, which is jointly determined by the MCS and the bandwidth; PHY Overhead represents the physical layer overhead.

[0099] In one or more possible embodiments, the AP dynamically adjusts the MCS according to the channel conditions of the STA.

[0100] In one or more possible embodiments, the reception duration T_BlockACK of the block acknowledgment frame is calculated according to the following formula:

[0101] T_BlockACK = Block ACK Size / STA_PHY_Rate + SIFS + Propagation Delay

[0102] Block ACK Size represents the size of the block acknowledgment frame;

[0103] STA_PHY_Rate represents the physical layer rate at which the STA feeds back the BlockACK, which is determined by the MCS and the bandwidth; SIFS represents the short inter-frame space, and Propagation Delay represents the signal propagation delay.

[0104] It should be noted that when the device 4 provided in the above embodiment executes the method for preventing the STA from dropping the line, only the above-mentioned division of each functional module is used for illustration. In actual applications, the above functions can be allocated to different functional modules according to needs, that is, the internal structure of the device is divided into different functional modules to complete all or part of the above functions. In addition, the device for preventing the STA from dropping the line provided in the above embodiment and the method embodiment for preventing the STA from dropping the line belong to the same concept. The implementation process is detailed in the method embodiment and will not be repeated here.

[0105] The serial numbers of the above embodiments of the present application are only for description and do not represent the advantages and disadvantages of the embodiments.

[0106] The embodiments of the present application also provide a computer storage medium, which can store multiple instructions, and the instructions are suitable for being loaded and executed by a processor to perform the method steps of the above Figure 2 illustrated embodiments. The specific execution process can refer to Figure 2 the specific description of the illustrated embodiments and will not be repeated here.

[0107] The present application also provides a computer program product, which stores at least one instruction, and the at least one instruction is loaded and executed by the processor to implement the method for preventing STA from dropping offline as described in the above various embodiments.

[0108] Please refer to Figure 5 , which is a schematic structural diagram of an AP provided by an embodiment of the present application. As Figure 5 shown, the AP500 may include: at least one processor 501, at least one network interface 504, a user interface 503, a memory 505, and at least one communication bus 502.

[0109] Among them, the communication bus 502 is used to realize the connection and communication between these components.

[0110] Among them, the user interface 503 may include a display screen (Display), a touch screen, etc.

[0111] Among them, the network interface 504 may optionally include a WI-FI interface.

[0112] Among them, the processor 501 may include one or more processing cores. The processor 501 connects various parts within the entire AP500 through various interfaces and lines, and by running or executing instructions, programs, code sets or instruction sets stored in the memory 505, and by calling data stored in the memory 505, it executes various functions of the AP500 and processes data. Optionally, the processor 501 may be implemented in at least one hardware form of digital signal processing (DSP), field-programmable gate array (FPGA), or programmable logic array (PLA). The processor 501 may integrate one or a combination of several of a central processing unit (CPU), a graphics processing unit (GPU), and a modem. Among them, the CPU mainly processes the operating system, the user interface, and application programs, etc.; the GPU is responsible for rendering and drawing the content to be displayed on the display screen; the modem is used to process wireless communication. It can be understood that the above modem may not be integrated into the processor 501 and may be implemented separately by a chip.

[0113] Among them, the memory 505 may include a Random Access Memory (RAM), or may also include a Read-Only Memory. Optionally, the memory 505 includes a non-transitory computer-readable storage medium. The memory 505 can be used to store instructions, programs, codes, code sets, or instruction sets. The memory 505 may include a program storage area and a data storage area. Among them, the program storage area can store instructions for implementing the operating system, instructions for at least one function (such as touch function, sound playback function, image playback function, etc.), instructions for implementing the above-mentioned various method embodiments, etc.; the data storage area can store the data involved in the above-mentioned various method embodiments. Optionally, the memory 505 may also be at least one storage device located far from the aforementioned processor 501. As Figure 5 shown, the memory 505, as a computer storage medium, may include an operating system, a network communication module, a user interface module, and application programs.

[0114] In Figure 5 the shown AP500, the user interface 503 is mainly used to provide an interface for the user to input and obtain the data input by the user; while the processor 501 can be used to call the application programs stored in the memory 505 and specifically execute the method as Figure 2 shown. The specific process can be referred to as Figure 2 shown, and will not be elaborated here.

[0115] Those of ordinary skill in the art can understand that all or part of the processes of implementing the above-mentioned method embodiments can be completed by instructing relevant hardware through a computer program. The program can be stored in a computer-readable storage medium. When the program is executed, it can include the processes of the above-mentioned method embodiments. Among them, the storage medium can be a magnetic disk, an optical disc, a read-only memory, or a random access memory, etc.

[0116] The above-disclosed are only the preferred embodiments of the present application. Of course, the scope of the rights of the present application cannot be limited thereby. Therefore, equivalent changes made according to the claims of the present application still fall within the scope covered by the present application.

Claims

1. A method for preventing an STA from dropping offline, characterized in that Including: Obtain the listening intervals of all STAs in the low-power mode, determine the maximum listening interval among the obtained listening intervals, and calculate the integer multiple LI between the maximum listening interval and the Beacon interval; Set the length of the aggregation constraint interval; wherein, the aggregation constraint interval consists of LI basic time intervals, and the length of each basic time interval is equal to one Beacon interval; When it is detected that the current trigger signal arrives, transmit data within the LI basic time intervals in the aggregation constraint interval; wherein, each basic time interval is sequentially provided with: an aggregated frame transmission interval, a block acknowledgment frame reception interval, and a Beacon frame transmission interval. The aggregated frame transmission interval is used to transmit aggregated frames, the block acknowledgment frame reception interval is used to receive the block acknowledgment frames of the aggregated frames, and the Beacon frame transmission interval is used to transmit Beacon frames; the length between the end moment of the aggregated frame transmission interval and the start moment of the Beacon frame transmission interval is set as T_left, and it satisfies T_left≥(the length of the block acknowledgment frame reception interval + 2*SIFS); After completing the data transmission within the aggregation constraint interval, wait for the next trigger signal; wherein, the occurrence period of the trigger signal is equal to Tloss / n, n is an integer greater than 1, and Tloss represents the STA disconnection duration.

2. The method according to claim 1, wherein The obtaining the listening intervals of all STAs in the low-power mode includes: When it is detected that an STA in the low-power mode is updated, obtain the listening intervals of all updated STAs in the low-power mode.

3. The method according to claim 1 or 2, characterized in that, n = 2 or 3 or 4.

4. The method according to claim 3, characterized in that, The aggregated frame includes multiple MPDUs, calculate the transmission duration of each MPDU according to the data volume and modulation and coding method of the MPDU; calculate the reception duration of the block acknowledgment frame according to the data volume and modulation and coding method.

5. The method according to claim 4, wherein Calculate the transmission duration T_MPDU of the MPDU according to the following formula: T_MPDU = (PHY RatePayload Size + MAC Header + FCS) / PHYrate + PHY Overhead; Wherein, PHY RatePayload Size represents the size of the payload, MAC Header represents the size of the MAC header, FCS represents the size of the FCS check field value; PHYrate represents the physical layer rate, which is jointly determined by the MCS and the bandwidth; PHYOverhead represents the physical layer overhead.

6. The method according to claim 5, characterized in that The AP dynamically adjusts the MCS according to the channel conditions of the STA.

7. The method according to claim 4 or 5 or 6, characterized in that Calculate the reception duration T_BlockACK of the block acknowledgment frame according to the following formula: T_BlockACK = Block ACK Size / STA_PHY_Rate + SIFS + Propagation Delay Block ACK Size represents the size of the block acknowledgment frame; STA_PHY_Rate represents the physical layer rate at which the STA feeds back the BlockACK, which is determined by the MCS and the bandwidth; SIFS represents the short inter-frame space, and Propagation Delay represents the signal propagation delay.

8. A device for preventing an STA from dropping offline, characterized in that, Including: An obtaining unit, configured to obtain the listening intervals of all STAs in the low power consumption mode, determine the maximum listening interval among the obtained listening intervals, and calculate the integer multiple LI between the maximum listening interval and the Beacon interval; A setting unit, configured to set the length of the aggregation constraint interval; wherein, the aggregation constraint interval is composed of LI basic time intervals, and the length of each basic time interval is equal to one Beacon interval; A triggering unit, configured to transmit data within the LI basic time intervals in the aggregation constraint interval when detecting that the current triggering signal arrives; wherein, each basic time interval is sequentially provided with: an aggregation frame sending interval, a block acknowledgment frame receiving interval, and a Beacon frame sending interval, the aggregation frame sending interval is used for sending an aggregation frame, the block acknowledgment frame receiving interval is used for receiving the block acknowledgment frame of the aggregation frame, and the Beacon frame sending interval is used for sending a Beacon frame; the length between the end moment of the aggregation frame sending interval and the start moment of the Beacon frame sending interval is set as T_left, and it satisfies T_left≥(the length of the block acknowledgment frame receiving interval + 2*SIFS); A waiting unit, configured to wait for the next triggering signal after completing the data transmission within the aggregation constraint interval; wherein, the occurrence period of the triggering signal is equal to Tloss / n, n is an integer greater than 1, and Tloss represents the STA disconnection duration.

9. A computer storage medium, characterized in that, The computer storage medium stores multiple instructions, and the instructions are adapted to be loaded and executed by a processor to perform the method steps of any one of claims 1 to 7.

10. An AP, characterized in that, Including: A processor and a memory; wherein, the memory stores a computer program, and the computer program is adapted to be loaded and executed by the processor to perform the method steps of any one of claims 1 to 7.

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