Adaptive canal sounding

Abstract

An access point (110) that includes the following: a processor (510); and a memory (520) coupled to the processor (510), wherein the memory (520) stores instructions that cause the processor (510) to perform actions that include: Determining (522) channel state information (CSI) of a channel between the client (120) and the access point (110) based on frames received from a client (120); Determine (524), based on the CSI, a configuration via a channel sounding between the access point and the client (120), wherein determining the configuration includes: In response to a difference between the CSI and a reference CSI of the channel exceeding an initial threshold, determine the configuration indicating that beamforming is enabled for the client (120) and trigger channel sounding; and In response to the configuration indicating that beamforming is enabled for the client (120), perform (526) channel sounding based on the configuration.

Description

background

[0001] Beamforming can be used to increase the reliability and / or range of communication between an access point (AP) and a client or station. For example, beamforming can involve performing channel sounding between the AP and the client. Channel sounding can be performed on a channel between the AP and the client to determine the characteristics of a wireless environment in which the AP and the client are deployed. In this case, it would be desirable to implement an effective channel sounding strategy.

[0002] US 2015 / 0326340A1 refers to a procedure for selecting a modulation coding scheme (MCS) for data transmission to a client station (STA).

[0003] US 2014 / 0071955A1 relates to a method for performing dynamic probing in a wireless communications device, comprehensively determining whether to perform probing based on the age of the current channel state information (CSI). Brief description

[0004] An access point according to claims 1 to 7, a method according to claims 8 to 14 and a non-transitory machine-readable medium according to claims 15 to 20 is disclosed. Brief description of the drawings

[0005] Embodiments of the present disclosure can be understood from the following detailed description when read together with the accompanying figures. As is customary in the industry, the various features are not drawn to scale. Indeed, the dimensions of the various features may be arbitrarily enlarged or reduced for the clarity of the discussion. Some examples of the present disclosure are described with reference to the following figures: Fig. shows an example environment in which embodiments of the present disclosure can be implemented; Fig. shows a schematic diagram of the rate of change of the channel state information (CSI) of a channel between a client and an AP in a static scenario according to the embodiments of the present disclosure; Fig. shows a schematic diagram of a CSI change rate of a channel between a client and an AP in a dynamic scenario according to the embodiments of the present disclosure; Fig. shows a schematic diagram of a configuration via channel sounding between an AP and a client according to the embodiments of the present disclosure; Fig. shows an example of an AP according to the embodiments of the present disclosure; and Fig. shows a flowchart of an example of a canal probing method according to the embodiments of the present disclosure. Detailed description

[0006] Wireless networks can be used to provide various types of communication for multiple users over the air using electromagnetic waves. This allows for different types of communication for multiple users without cables, wires, or other physical electrical conductors to connect devices within the wireless network. Examples of the different types of communication that can be provided by wireless networks include voice communication, data communication, multimedia services, and more.

[0007] An example of a wireless network is a wireless local area network (WLAN). WLANs can include multiple stations (STAs) and / or access points (APs) that can communicate over a variety of wireless channels. As used here, an AP is a network hardware device that allows a wirelessly compatible device (such as an STA) to connect to a network. The terms "STA" and "client" may be used interchangeably hereafter. As used here, a WLAN generally refers to a communication network that connects two or more devices using a wireless distribution method (such as spread spectrum or orthogonal frequency-division multiplexing radio) and typically connects to the internet via an access point. Thus, a WLAN allows users to move around within a local coverage area and still remain connected to the network.

[0008] An access point (AP) can enable data center devices (STAs) to connect to a network such as the internet. As used here, an AP generally refers to a receiving point for any known or suitable wireless technology that may be developed in the future. In particular, the term "AP" is not limited to 802.11-based APs of the Institute of Electrical and Electronics Engineers (IEEE). An AP is generally an electronic device that can connect wireless devices to a wired network using various communication standards. An STA, or client, is a device capable of using the IEEE 802.11 protocol. Examples of STAs include smartphones, laptops, physical, non-virtualized computing devices, personal digital assistants, and so on. In some examples, an STA, or client, might be a device that uses an IEEE 802.11 protocol.It has an 11-compliant interface for media access control (MAC) and the physical layer (PHY) to a wireless medium (WM).

[0009] Wireless networks such as WLANs can use one or more wireless communication technologies, such as orthogonal frequency division multiplexing (OFDM). In an OFDM-based wireless network, a data stream is split into multiple data substreams. These data substreams can be transmitted over different OFDM carriers, which can be referred to as tones or frequency tones. Some wireless networks can use a single-in, single-out (SISO) communication approach, where each STA and / or AP uses a single antenna. Other wireless networks can use a multiple-in, multiple-out (MIMO) communication approach, where an STA and / or AP uses multiple transmit and multiple receive antennas. WLANs, as defined in the IEEE wireless communication standards, such as IEEE 802.11a, IEEE 802.11n, IEEE 802.11ac, etc., can use OFDM to transmit and receive signals. Furthermore, WLANs that, for example,based on the IEEE 802.11n or IEEE 802.11ac standards, using OFDM and MIMO.

[0010] Beamforming (e.g., explicit transmit beamforming) can be used to increase the reliability and / or range of communication (e.g., a communication link) between an access point (AP) and a storage access point (STA) or client. In some examples, beamforming may involve channel sounding between a beamformer and a beamforming receiver. A beamformer can be a transmitter (Tx), and a beamformee can be a receiver (Rx). For example, an AP can be a beamformer and an STA can be a beamformee.

[0011] Channel probing can be performed on channel paths between access points (APs) and / or storage access points (STAs) to determine the characteristics of a wireless environment in which the APs and / or STAs are deployed. The characteristics determined from channel probing can be calculated and / or reported per OFDM subcarrier. As used herein, "channel probing" is a technique that can be used to determine and / or evaluate characteristics of a wireless network. For example, multidimensional spatiotemporal signals can propagate between APs and / or STAs in the wireless environment. Channel probing can involve processing these multidimensional spatiotemporal signals to estimate and / or evaluate the characteristics of the wireless network. These estimated and / or evaluated characteristics can be used to mitigate the effects of multipath wave propagation in a wireless network.

[0012] Channel sounding can be used to recalibrate a beamformer to employ modified transmit weights for pre-coding transmissions to a beamformee. These modified transmit weights can be compatible with the conditions associated with a channel between the beamformer and the beamformee.

[0013] Beamforming can increase the index value of a modulation coding scheme (MCS). For example, beamforming can increase the MCS index value by 1. This increase can correspond to an increase in physical layer (PHY) rates. For example, an increase of 1 MCS index value can correspond to a 10-15% increase in PHY transmission rates. Accordingly, as the number of STAs associated with an access point (AP) increases, the overhead associated with channel probing can become greater than the gains associated with channel probing. Interference between APs and / or STAs can also increase as the number of APs and / or STAs associated with a given wireless network increases.

[0014] Traditionally, beamforming and / or channel sounding can be performed within a static time interval. For example, a specific time period can be allocated for performing beamforming and / or channel sounding. This time interval can remain constant between a beamformer and a beamforming receiver, regardless of the channel conditions. This time interval can be referred to here as the "beamforming interval" or the "channel sounding interval," depending on whether the focus is on beamforming or channel sounding. However, conventional channel sounding strategies are unable to account for changes in the environment and client behavior and therefore cannot adapt to different environments.

[0015] A specific example: In a dynamic scenario, the channel between the access point (AP) and the client is a fast, time-varying channel. Such a scenario could be, for example, an industrial setting where wireless robots, trailers, etc., move quickly. Furthermore, such a scenario could also be one where the AP is mounted at an entrance or lobby with many clients, obstacles, or refractors. The propagation paths or channels between the AP and the clients change with the movement of the clients, obstacles, or refractors. In this case, beamforming must be performed frequently. Otherwise, the previously trained beamforming control matrices will no longer be able to account for the channel changes. Outdated steer matrices therefore lead to a high packet error rate (PER) and degrade transmission performance.

[0016] In contrast, beamforming in a static scenario does not need to be performed frequently, as the channel changes only slightly and the control matrices remain unchanged. In fact, the channel probing required for beamforming becomes a significant overhead. For example, a channel probing procedure can take up to 0.2 ms, and in a performance build with 50 clients, the channel probing interval for a single user (SU) at the AP can be 50 ms. In this case, the total SU channel probing overhead is approximately... 20%(50×0.2ms×150ms) the broadcast time. Even worse: Since the SU channel sounding and the multi-user channel sounding (MU) are performed in parallel, the overall overhead is even higher.

[0017] It becomes clear that the dynamic scenario requires frequent canal sounding, while the static scenario, for efficiency reasons, requires infrequent sounding. However, traditional canal sounding strategies are merely a compromise between these two scenarios. Consequently, conventional canal sounding strategies are inefficient in both scenarios.

[0018] Embodiments of the present disclosure propose a solution for channel sounding to address the problems mentioned above and one or more other potential problems. This solution allows an access point (AP) to perform channel sounding at different time intervals or even to disable beamforming based on the channel information index (CSI). If the CSI change rate exceeds a first threshold, the access point can disable beamforming. If the CSI change rate does not exceed the first threshold but does exceed a second threshold below the first, the access point can perform channel sounding at a first time interval. Alternatively, if the CSI change rate does not exceed the second threshold, the AP can perform channel sounding at a second time interval. The second time interval is longer than the first.In this way, adaptive canal probing can be performed.

[0019] Further advantages of embodiments of the present disclosure are described with reference to the example implementation described below. To illustrate the basic principles and various embodiments of the present disclosure, reference is made below to the following: Fig. until Fig. referred.

[0020] Fig. Figure 100 shows an example environment in which embodiments of the present disclosure can be implemented. As shown in Fig. As shown, environment 100 comprises an AP 110 and a variety of clients 120-1 to 120-N (collectively referred to as "clients 120" or "STAs 120," where N is an integer greater than 1). The AP 110 can provide a wireless connection to the client 120. To enable the wireless connection, channel probing (e.g., NDP probing (Null Data Packet)) or beamforming can be performed between the AP 110 and the client 120.

[0021] During channel sounding, a control matrix can be determined for the digital encoding of data and the control of signals in a specific direction. For example, a wireless channel using Multiple Input Multiple Output (MIMO) can be divided into multiple subcarriers by Orthogonal Frequency Division Multiplexing (OFDM). The AP 110 can transmit long training symbols (LTFs), containing predefined symbols for each subcarrier, in the packet preamble. Upon receiving the LTFs, the Client 120 can estimate the CSI matrix based on the received signals and the original LTFs and transmit the CSI matrix to the AP 110. The AP 110 can then generate the control matrix using the CSI matrix.

[0022] Since the channel sounding process aims to determine the CSI or control matrix based on the CSI, the CSI can be used to optimize the channel sounding. The CSI can characterize how wireless signals propagate from the AP 110 to the client 120 at specific carrier frequencies. The CSI amplitude and phase can be affected by multipath effects such as amplitude attenuation and phase shift. Each CSI can represent a channel frequency response (CFR). The CSI can, for example, describe channel characteristics such as channel decay, dispersion, or signal drop-off.

[0023] The AP 110 can collect the CSI of uplink frames received by the client 120, such as acknowledgments (ACKs), block acknowledgments (BAs), data frames, or management frames. In some configurations, the CSI can be collected on the same subcarriers and using the same transmission mode. For example, it is not permissible to sometimes collect the CSI on a 20 MHz channel and sometimes on specific OFDMA (Orthogonal Frequency Division Multiple Access Resource Units). This is because frequency consistency must be maintained to accurately estimate channel changes.

[0024] By analyzing the CSI, the AP 110 can assess channel changes and optimize channel probing. Specifically, the AP 110 can evaluate channel change trends for client 120 by analyzing the CSI. With this knowledge of the channel change trend, the AP 110 can gain deep insights into the channel model of client 120, enabling it to select different channel probing strategies for different clients 120.

[0025] To implement such adaptive channel probing, AP 110 determines the CSI of a channel between client 120 and AP 110 based on the frames received from client 120. As described above, these frames can be ACKs, BAs, data frames, or management frames, etc. AP 110 then determines a channel probing configuration based on the CSI between AP 110 and client 120. In some embodiments, AP 110 can determine the channel's CSI change rate. In this case, AP 110 can determine the configuration based on the CSI change rate. In some embodiments, the CSI change rate can be determined based on an accumulated CSI change rate or an instantaneous CSI change rate.

[0026] In some embodiments, the accumulated CSI change rate can be determined, for example, based on the following equation: ACCUMULATED_CSI_CHANGE_RATEN=‖CSIn−CSI0‖‖CSI0‖×100% where ACCUMULATED-CSI-CHANGE-RATE n , represents the cumulative CSI rate of change of the nth frame, CSI n CSI represents the CSI of the nth frame, and CSI0 represents the reference CSI that was collected at the time the previous channel sounding was performed.

[0027] In some embodiments, the instantaneous CSI change rate can be determined, for example, using the following equation: INSTANTANEOUS_CSI_CHANGE_RATEN=‖CSIn−CSIn−1‖‖CSIn−1‖×100% where INSTANTANEOUS_CSI_CHANGE RATE n For the current CSI change rate of the nth frame, CSI stands for n represents the CSI of the nth frame and CSI n-1 stands for the CSI of the (n-1)th framework.

[0028] In some embodiments, the CSI change rate can be the accumulated CSI change rate or the instantaneous CSI change rate. Alternatively, in some embodiments, the CSI change rate can be the average of the accumulated CSI change rates over a certain period or the average of the instantaneous CSI change rates over a certain period.

[0029] Fig. and Fig. Schematic diagrams 200 and 300 show the CSI change rates of the channel between client 120 and AP 110 in a static scenario and a dynamic scenario, respectively, according to the embodiments of the present disclosure. As shown in Fig. and Fig. As shown, the CSI change rate remains at a relatively low level in the static scenario (e.g., a scenario where client 120 is static or moves slightly). As shown from Fig. As can be seen, the accumulated CSI change rate (210) and the instantaneous CSI change rate (220) each remain at a relatively low level. In comparison, the CSI change rate remains at a relatively high level in the dynamic scenario (e.g., in a scenario where the client (120), obstacles, or refractors are moving rapidly). As can be seen from Fig. As can be seen, the accumulated CSI change rate 310 and the current CSI change rate 320 each remain at a relatively high level.

[0030] Since the CSI changes slowly or remains unchanged in a static scenario, the AP 110 can select a longer channel probing interval for client 120 with a static channel to reduce probing overhead and improve transmission performance. Conversely, the AP 110 can select a shorter channel probing interval for client 120 with a time-varying channel to update the CSI in a timely manner. The faster the channel changes, the more frequently channel probing can be performed. Because the CSI determined during channel probing may not keep pace with the channel changes, the AP 110 can even disable beamforming for client 120 with an extremely time-varying channel.

[0031] Such an adaptive channel sounding interval can be implemented with a channel sounding configuration between the AP 110 and the Client 120. Fig. Figure 400 shows a schematic diagram of a configuration for channel sounding between the AP 110 and the client 120 according to the embodiments of the present disclosure. As shown in Fig. As shown, if the CSI change rate exceeds an initial threshold of 410, indicating that the channel between client 120 and AP 110 is changing drastically over time, AP 110 can determine the configuration that indicates beamforming is disabled for client 120. In this case, AP 110 can disable beamforming and / or channel sounding for client 120.

[0032] Otherwise, if the CSI change rate does not exceed the first threshold of 410, AP 110 can determine the configuration indicating that beamforming is enabled for client 120. In this case, AP 110 can perform channel sounding based on the configuration.

[0033] In some embodiments, if the CSI change rate does not exceed the first threshold of 410, but exceeds a second threshold of 420 below the first threshold of 410, indicating that the channel between client 120 and AP 110 is changing over time, AP 110 can determine the configuration that specifies a first time interval for performing channel sounding. In this case, AP 110 can send channel sounding packets (e.g., null data packets) to client 120 during the first time interval.

[0034] If the CSI change rate does not exceed the second threshold of 420, indicating that the channel between client 120 and AP 110 is changing slowly or remaining unchanged, AP 110 can alternatively configure a second time interval for channel sounding. This second time interval can exceed the first. In this case, AP 110 can send channel sounding packets (e.g., null data packets) to client 120 during the second time interval.

[0035] In addition to performing channel probing based on the CSI change rate, asynchronous channel probing can also be triggered when the current channel state deviates significantly from the original channel state. Specifically, in some embodiments, if the difference between the channel's CSI and reference CSI exceeds a third threshold, the AP 110 can determine the configuration indicating that beamforming is enabled for client 120, and channel probing is initiated. As described above, the reference CSI can be determined during the preceding channel probing. In this case, the AP 110 can immediately send channel probing packets to client 120.

[0036] In this way, the canal sounding can be adapted to different scenarios and the performance of beamforming can be improved.

[0037] Since the CSI is determined based on uplink frames and not beamforming feedback, no additional channel soundings are required to assess channel changes. This means that the AP 110 does not have to wait for a channel sounding interval to know the channel state and is therefore able to adapt to channel changes immediately and efficiently.

[0038] Furthermore, CSI is more accurate than RSSI in many scenarios. For example, when the AP 110 adjusts its transmit power, the RSSI changes, but the channel state remains unchanged. Instead, the CSI is unaffected by the altered transmit power.

[0039] Fig. Figure 1 shows an example of an AP 110 according to the embodiments of the present disclosure. The AP 110 comprises a processor 510 and a memory 520 connected to the processor 510. The memory 520 stores instructions 522, 524, and 526 to cause the processor 510 to perform certain actions.

[0040] As in Fig. As shown, memory 520 stores instruction 522 to determine channel status information (CSI) of a channel between the client and the access point based on frames received from the client. Additionally, memory 520 stores instruction 524 to determine a channel sounding configuration between the access point and the client based on the CSI. Furthermore, memory 520 stores instruction 526 to perform channel sounding based on the configuration indicating that beamforming is enabled for the client.

[0041] In some embodiments, the AP 110 may disable beamforming and / or channel sounding for the client in response to the configuration indicating that beamforming is disabled for the client.

[0042] In some embodiments, the AP 110 can determine the configuration based on the channel's CSI change rate. If the CSI change rate exceeds a certain threshold, the AP 110 can determine the configuration indicating that beamforming is disabled for the client. If the CSI change rate does not exceed the certain threshold, the AP 110 can determine the configuration indicating that beamforming is enabled for the client.

[0043] In some embodiments, the AP 110 can determine the configuration based on the condition that the CSI change rate does not exceed the first threshold but does exceed a second threshold below the first. This configuration specifies a first time interval for performing channel sounding. Furthermore, to perform channel sounding based on the configuration, the AP 110 can send channel sounding packets to the client during the first time interval.

[0044] In some embodiments, the AP 110 can determine the configuration, based on the finding that the CSI change rate does not exceed the second threshold, and specify a second time interval for performing channel sounding. For example, the second time interval may exceed the first. Furthermore, to perform channel sounding based on the configuration, the AP 110 can send channel sounding packets to the client during the second time interval.

[0045] In some embodiments, the AP 110 can further determine the configuration indicating that beamforming is enabled for the client and channel sounding is triggered in response to a difference between the channel's CSI and reference CSI that exceeds a third threshold. For example, the reference CSI can be determined in response to a previously performed channel sounding. To perform the channel sounding based on the configuration, the AP 110 can also send a channel sounding packet to the client.

[0046] In some embodiments, the frames may include acknowledgments, block acknowledgments, data frames, or management frames.

[0047] Fig. Figure 1 shows a flowchart of an example method 600 for canal sounding according to the embodiments of the present disclosure. It is understood that method 600 can be carried out by AP 110, as described with reference to the Fig. described.

[0048] At 610, the AP 110 determines channel status information (CSI) for a channel between the client and the access point based on frames received from the client. At 620, the AP 110 determines a channel sounding configuration between the access point and the client based on the CSI. At 630, in response to the configuration indicating that beamforming is enabled for the client, the AP 110 performs the channel sounding based on the configuration.

[0049] In some embodiments, the AP 110 may disable beamforming for the client in response to the configuration indicating that beamforming is disabled for the client.

[0050] In some embodiments, the AP 110 can determine the configuration based on the channel's CSI change rate. If the CSI change rate exceeds a certain threshold, the AP 110 can determine the configuration indicating that beamforming is disabled for the client. If the CSI change rate does not exceed the certain threshold, the AP 110 can determine the configuration indicating that beamforming is enabled for the client.

[0051] In some embodiments, the AP 110 can determine the configuration based on the condition that the CSI change rate does not exceed the first threshold but does exceed a second threshold below the first. This configuration specifies a first time interval for performing channel sounding. Furthermore, to perform channel sounding based on the configuration, the AP 110 can send channel sounding packets to the client during the first time interval.

[0052] In some embodiments, the AP 110 can determine the configuration, based on the finding that the CSI change rate does not exceed the second threshold, and specify a second time interval for performing channel sounding. For example, the second time interval may exceed the first. Furthermore, to perform channel sounding based on the configuration, the AP 110 can send channel sounding packets to the client during the second time interval.

[0053] In some embodiments, the AP 110 can further determine the configuration indicating that beamforming is enabled for the client and channel sounding is triggered in response to a difference between the channel's CSI and reference CSI that exceeds a third threshold. For example, the reference CSI can be determined in response to a previously performed channel sounding. To perform the channel sounding based on the configuration, the AP 110 can also send a channel sounding packet to the client.

[0054] In some embodiments, the frames may include acknowledgments, block acknowledgments, data frames, or management frames.

[0055] In this way, the canal sounding can be adapted to different scenarios, thus improving the performance of beamforming.

[0056] Program code or instructions for carrying out the procedures of this disclosure may be written in any combination of one or more programming languages. These program codes or instructions may be fed to a processor or controller of a general-purpose computer, a specialized computer, or any other programmable data processing device, such that when executed by the processor or controller, the program codes perform the functions / operations specified in the flowcharts and / or block diagrams. The program code or instructions may be executed entirely on one machine, partially on the machine, as a standalone software package, partially on the machine and partially on a remote machine, or entirely on the remote machine or server.

[0057] In the context of this disclosure, a machine-readable medium can be any tangible medium capable of containing or storing a program for use by or in conjunction with a command-execution system, apparatus, or device. The machine-readable medium can be a machine-readable signaling medium or a machine-readable storage medium. A machine-readable medium can be, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, device, or apparatus, or a suitable combination thereof.More specific examples of a machine-readable storage medium would be an electrical connection with one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0058] Even though the processes are presented in a specific order, this does not mean that these processes must be executed in the presented order or sequentially, or that all presented processes must be executed to achieve the desired results. Multitasking and parallel processing can be advantageous under certain circumstances. Certain features described in connection with individual embodiments can also be implemented in combination within a single embodiment. Conversely, various features described in connection with a single embodiment can also be implemented separately in multiple embodiments or in any suitable subcombination.

[0059] The preceding detailed description of this disclosure refers to the accompanying drawings, which form part of this disclosure and illustrate how examples of the disclosure can be implemented. These examples are described in sufficient detail to enable those skilled in the art to put the examples of this disclosure into practice, and it is understood that other examples may be used and that process, electrical, and / or structural modifications may be made without departing from the scope of this disclosure.

Claims

[1] An access point (110) comprising the following: a processor (510); and a memory (520) coupled to the processor (510), wherein the memory (520) stores instructions that cause the processor (510) to perform actions that include: Determining (522) channel state information (CSI) of a channel between the client (120) and the access point (110) based on frames received from a client (120); Determine (524), based on the CSI, a configuration via a channel sounding between the access point and the client (120), wherein determining the configuration includes: In response to a difference between the CSI and a reference CSI of the channel exceeding an initial threshold, determine the configuration indicating that beamforming is enabled for the client (120) and trigger channel sounding; and In response to the configuration indicating that beamforming is enabled for the client (120), perform (526) channel sounding based on the configuration. [2] The access point (110) according to claim 1, wherein the actions further comprise: In response to the configuration indicating that beamforming is disabled for client (120), disable beamforming for client (120). [3] The access point (110) according to claim 1, wherein determining the configuration comprises: Determining a CSI change rate of the channel based on the CSI; according to a determination that the CSI change rate exceeds a second threshold, determine the configuration indicating that beamforming is disabled for client (120); and According to a determination that the CSI change rate does not exceed a second threshold, determine the configuration that specifies that beamforming is enabled for the client (120). [4] The access point (110) according to claim 3, wherein determining the configuration comprises: According to a determination that the CSI change rate does not exceed the second threshold but exceeds a third threshold below the second threshold, determining the configuration that specifies a first time interval for performing the canal sounding; and the canal probing process includes, based on the configuration: Sending channel probe packets to the client (120) in the first time interval. [5] The access point (110) according to claim 4, wherein determining the configuration comprises: According to a determination that the CSI change rate does not exceed the third threshold, determine the configuration that specifies a second time interval for performing the canal sounding, the second time interval exceeding the first time interval; and the canal probing process includes, based on the configuration: Sending channel probe packets to the client (120) in the second time interval. [6] The access point (110) according to claim 1, wherein the reference CSI is determined in response to a prior canal sounding; and wherein performing the canal sounding based on the configuration comprises: Sending a channel probe packet to the client (120). [7] The access point (110) according to claim 1, wherein the frames comprise: Confirmations; Block confirmations; Data frame; or Administrative framework. [8] A method (600) comprising the following: Determine, at an access point (110) and based on uplink frames received from a client (120), of channel state information (CSI) of a channel between the client (120) and the access point (110); Determine, based on the CSI, a configuration via channel sounding between the access point (110) and the client (120), wherein determining the configuration includes: In response to a difference between the CSI and a reference CSI of the channel exceeding an initial threshold, determine the configuration indicating that beamforming is enabled for the client (120) and trigger channel sounding; and In response to the configuration indicating that beamforming is enabled for the client (120), perform channel sounding based on the configuration. [9] The method (600) according to claim 8 further comprising: In response to the configuration indicating that beamforming is disabled for client (120), disable beamforming for client (120). [10] The method (600) according to claim 8, comprising determining the configuration: Determining a CSI change rate of the channel based on the CSI; according to a determination that the CSI change rate exceeds a second threshold, determine the configuration indicating that beamforming is disabled for client (120); and According to a determination that the CSI change rate does not exceed a second threshold, determine the configuration that specifies that beamforming is enabled for the client (120). [11] The method (600) according to claim 10, comprising determining the configuration: According to a determination that the CSI change rate does not exceed the second threshold but exceeds a third threshold below the second threshold, determining the configuration that specifies a first time interval for performing the canal sounding; and the canal probing process includes, based on the configuration: Sending channel probe packets to the client (120) in the first time interval. [12] The method (600) according to claim 11, comprising determining the configuration: According to a determination that the CSI change rate does not exceed the third threshold, determine the configuration that specifies a second time interval for performing the canal sounding, the second time interval exceeding the first time interval; and the canal probing process includes, based on the configuration: Sending channel probe packets to the client (120) in the second time interval. [13] The method (600) according to claim 8, wherein the reference CSI is determined in response to a prior canal sounding; and wherein performing the canal sounding based on the configuration comprises: Sending a channel probe packet to the client (120). [14] The method (600) according to claim 8, wherein the uplink frames comprise the following: Confirmations; Block confirmations; Data frame; or Administrative framework. [15] A non-transitory machine-readable medium comprising machine-executable instructions which, when executed on a device, cause the device to: Determining channel state information (CSI) of a channel between another device and the device based on frames received from the other device; Determine, based on the CSI, a configuration via a channel probe between the device and the other device, wherein determining the configuration includes: In response to a difference between the CSI and a reference CSI of the channel exceeding an initial threshold, determine the configuration indicating that beamforming is enabled for the client (120) and trigger channel sounding; and In response to the configuration indicating that beamforming is enabled for the further device, the channel sounding is performed based on the configuration. [16] The non-transitory machine-readable medium according to claim 15, wherein the instructions further comprise instructions which, when executed on the device, cause the device to: In response to the configuration indicating that beamforming is disabled for the other device, disable beamforming for the other device. [17] The non-transitory machine-readable medium according to claim 15, wherein determining the configuration comprises: Determining a CSI change rate of the channel based on the CSI; according to a determination that the CSI change rate exceeds a second threshold, determining the configuration that indicates beamforming is disabled for the further device; and According to a determination that the CSI change rate does not exceed a second threshold, determine the configuration that indicates beamforming is enabled for the further device. [18] The non-transitory machine-readable medium according to claim 17, wherein determining the configuration comprises: According to a determination that the CSI change rate does not exceed the second threshold but exceeds a third threshold below the second threshold, determining the configuration that specifies a first time interval for performing the canal sounding; and the canal probing process includes, based on the configuration: Sending channel sounding packets to the other device in the first time interval. [19] The non-transitory machine-readable medium according to claim 18, wherein determining the configuration comprises: According to a determination that the CSI change rate does not exceed the third threshold, determine the configuration that specifies a second time interval for performing the canal sounding, wherein the second time interval exceeds the first time interval; and the canal probing process includes, based on the configuration: Sending channel sounding packets to the other device in the second time interval. [20] The non-transitory machine-readable medium according to claim 15, wherein the frames comprise: Confirmations; Block confirmations; Data frame; or Administrative framework.

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