Wireless communication method, access point device, and computer program product

Abstract

The present disclosure relates to a wireless communication method, an access point device and a computer program product. The wireless communication method is a method performed by a serving AP device currently associated with a client device, comprising: sending a first request to each of one or more candidate AP devices within a same extended service set as the serving AP device, the first request instructing each candidate AP device to measure a signal strength from the client device; receiving a first reply including a measurement result of the signal strength from each candidate AP device; determining, based at least on the first reply, a target AP device to which the client device is to roam to associate from the one or more candidate AP devices; and sending a second request to the client device, the second request instructing the client device to roam to associate to the target AP device.

Description

Technical Field

[0001] This disclosure relates to wireless communication technology, and more particularly to wireless communication methods, access point devices, and computer program products for wireless roaming in multi-access point (AP) networking scenarios. Background Technology

[0002] Multiple access point (AP) networking is a common method in modern wireless local area networks (WLANs). In a multi-AP network scenario, client devices can associate with any AP device within the coverage area. When a client device moves, the signal strength received from each AP device will dynamically change. To ensure good communication, the client device should connect to the AP device with the best service quality in a timely manner. The process of a client device switching from associating with one AP device to associating with another AP device within the network is called client device roaming.

[0003] To determine which access point (AP) device to roam to, client devices need to frequently interact with their currently associated service AP, resulting in issues such as high roaming latency, channel resource consumption, and perceived deterioration in service quality for users. Therefore, there is a need to improve the existing wireless roaming process. Summary of the Invention

[0004] In view of at least one of the above problems, this disclosure provides an access point device and its communication method and computer program product for optimizing wireless roaming in multi-AP networking scenarios.

[0005] According to one aspect of this disclosure, a wireless communication method is provided for an access point (AP) device, the AP device being a serving AP device currently associated with a client device, the method comprising: sending a first request to each of one or more candidate AP devices located within the same extended service set as the serving AP device, the first request instructing each candidate AP device to measure a signal strength from the client device; receiving a first response from each candidate AP device including a measurement result of the signal strength; determining, at least based on the first response, a target AP device from the one or more candidate AP devices to which the client device wishes to roam; and sending a second request to the client device, the second request instructing the client device to roam associated with the target AP device.

[0006] According to another aspect of this disclosure, an access point (AP) device is provided, the AP device being a serving AP device currently associated with a client device, comprising: one or more processors; a memory coupled to at least one of the one or more processors; and a computer program stored in the memory, the computer program, when executed by at least one of the one or more processors, causing the AP device to perform the method as described above.

[0007] According to another aspect of this disclosure, a computer program product is provided, including a computer program that, when executed by a processor of an access point (AP) device, causes the AP device to perform the method described above.

[0008] According to the access point device, communication method of the access point device, and computer program product disclosed herein, when a client device needs to perform wireless roaming, the target AP device to which the client device should roam is determined based on the communication interaction between the serving AP device and candidate AP devices within the same extended service set. Thus, the serving AP device can promptly determine the target AP device based on the measurement results reported by the candidate AP devices and provide this information to the client device, reducing roaming latency. Furthermore, since frequent communication interaction with the client device is not required, it avoids consuming the client device's channel resources, improves communication quality degradation caused by client roaming decisions, and optimizes the wireless roaming process in multi-AP networking scenarios. Attached Figure Description

[0009] The above and other objects, features, and advantages of this disclosure will become more apparent from a more detailed description of the embodiments thereof in conjunction with the accompanying drawings. The drawings are provided to provide a further understanding of the embodiments of this disclosure and form part of the specification. The drawings, together with the embodiments of this disclosure, are used to interpret this disclosure and do not constitute a limitation thereof. In the drawings, unless expressly indicated, like reference numerals generally represent like parts, steps, or elements.

[0010] Figure 1 An exemplary architecture of a wireless communication system according to embodiments of the present disclosure is illustrated;

[0011] Figure 2 A flowchart illustrating a wireless communication method for an AP device according to an embodiment of the present disclosure is provided.

[0012] Figure 3 A schematic diagram illustrating a wireless roaming process according to an embodiment of the present disclosure is shown;

[0013] Figure 4 An exemplary block diagram of an AP device according to an embodiment of the present disclosure is shown.

[0014] Those skilled in the art will understand that the elements in the accompanying drawings are illustrated for simplicity and clarity and are not necessarily drawn to scale. For example, the dimensions of some elements in the illustrations, block diagrams, or flowcharts may be exaggerated relative to other elements to aid in the accurate understanding of this embodiment. Detailed Implementation

[0015] The following detailed description is illustrated in the accompanying drawings. While exemplary embodiments are described herein, modifications, adaptations, and other implementations are possible. For example, components and steps illustrated in the drawings may be replaced, added, or modified, and the exemplary methods described herein may be modified by replacing, reordering, deleting, or adding steps to the disclosed methods. Therefore, the following detailed description is not limited to the disclosed embodiments and examples. Rather, the appropriate scope of the invention is determined by the appended claims.

[0016] In the detailed description below, numerous specific details are set forth in order to provide a thorough understanding of certain aspects. However, those skilled in the art will understand that some aspects can be practiced without these specific details. In other instances, well-known methods, procedures, components, units, and / or circuits have not been described in detail to avoid obscuring the discussion.

[0017] The use of terms such as “on one aspect,” “an aspect,” “example aspect,” and “various aspects” indicates that an aspect described in this way may include a specific feature, structure, or characteristic, but not every aspect necessarily includes the implementation of that specific feature, structure, or characteristic. Furthermore, the repeated use of the phrase “on one aspect” does not necessarily refer to the same aspect, although it may.

[0018] As used herein, unless otherwise stated, ordinal adjectives such as “first,” “second,” “third,” etc., are used to describe general objects only to indicate different instances of similar objects mentioned, and are not intended to imply that the objects described in this way must have a given order in time, space, sequence, or any other way.

[0019] Furthermore, the technical features involved in the different embodiments of this disclosure described below can be combined with each other, provided that there is no conflict between them.

[0020] In this disclosure, an access point (AP) device is a communication device that can communicate with non-access point (non-AP) devices (e.g., stations (STAs) or client devices) in a WLAN and allow non-AP devices to connect to the network. AP devices are typically connected to a router via a wired network as standalone devices, but they can also be integrated with or used within a router.

[0021] In this disclosure, a non-AP device (e.g., a client device or station) is a communication device capable of communicating with an AP device to obtain various communication services, such as voice, video, packet data, messaging, broadcasting, etc. In the following description, a client device or station is simply referred to as an STA device. An STA device can be any device that includes IEEE 820.11 compliant Media Access Control (MAC) and Physical Layer (PHY) interfaces to the wireless medium (WM). For example, an STA device can be a laptop computer, desktop personal computer (PC), personal digital assistant (PDA), access point, or Wi-Fi phone in a WLAN environment. STA devices can be fixed or mobile. In a WLAN environment, the terms "STA," "STA device," "client device," "wireless client," "user," and "user equipment" are generally used interchangeably.

[0022] In this disclosure, a STA device in a WLAN can function as an AP device in different scenarios, and vice versa. This is because communication devices in the context of IEEE 820.11 (Wi-Fi) technology may include both STA and AP hardware components. In this way, the communication device can switch between STA mode and AP mode based on the actual WLAN conditions and / or requirements. In the following description, STA device may refer to a STA device that is not implemented as an AP device.

[0023] Figure 1 An exemplary architecture of a wireless communication system 100 according to embodiments of the present disclosure is illustrated. The wireless communication system 100 may conform to the IEEE 802.11 series of standards. Figure 1 As shown, the wireless communication system 100 may include multiple AP devices (e.g., Figure 1 The AP devices 101, 102, and 103 and one client device 104 are included. It should be understood that... Figure 1 The number of AP devices and client devices shown is merely an example and does not impose any limitation on any embodiment of this disclosure.

[0024] exist Figure 1In the example, client device 104 is associated with AP device 101. This can also be described as client device 104 joining the Basic Service Set (BSS) of AP device 101, making AP device 101 a serving AP device for client device 104. Each AP device's BSS can have a unique Basic Service Set Identifier (BSSID) and a certain coverage area. An AP device can associate with client devices within the coverage area of ​​its BSS and provide communication services. In some examples, a BSS's BSSID can be the MAC address of the corresponding AP device. Furthermore, multiple AP devices' BSSs can be combined to form an Extended Service Set (ESS). Each BSS belonging to the same ESS can have the same Service Set Identifier (SSID) and its own distinct BSSID. Figure 1 In the example, AP devices 101, 102, and 103 belong to the same ESS.

[0025] Because the movement of client device 104 increases the distance between it and serving AP device 101, the signal quality between client device 104 and serving AP device 101 deteriorates. Therefore, client device 104 can perform wireless roaming and join the BSS of an AP device with better signal quality within the same ESS. Figure 1 In the example, client device 104 is simultaneously within the coverage area A1 of the BSS of AP device 101, the coverage area A2 of the BSS of AP device 102, and the coverage area A3 of the BSS of AP device 103. Therefore, it can roam to any of the AP devices 102 and 103 that are not serving AP devices. In this case, it is necessary to decide which target AP device client device 104 should roam to.

[0026] The IEEE 802.11k (Radio Resource Measurement) and IEEE 802.11v (Radio Network Management) protocols define the procedures related to wireless roaming for client devices. Simply put, when a client device needs to roam wirelessly, the currently associated serving access point (AP) can send a Measurement Request Frame to the client device according to the 802.11k protocol, instructing the client device to measure information (Measurement Request Element) related to the channel, signal quality, etc., of other AP devices within the ESS. In response to this Measurement Request Frame, the client device performs radio resource measurements and provides the measurement results (Measurement Report Element) to the serving AP device via a Measurement Report Frame. The Measurement Request Element and Measurement Report Element correspond one-to-one. Subsequently, according to the 802.11v protocol, the serving AP device can respond to a BSS Transition Management Query initiated by the client device by sending a BSS Transition Management Request frame containing an evaluated list of better candidate AP devices, based on the content of the measurement report frame reported by the client device. Upon receiving the BSS Transition Management Request frame, the client device can decide whether to initiate a roaming procedure for one of the AP devices in the list and send a BSS Transition Management Response frame to the serving AP device to report the processing result of the roaming suggestion.

[0027] As described above, the network-side recommendation of target AP devices is based on the client devices performing radio resource measurements and reporting the results. This disclosure recognizes that this recommendation mechanism relies on the client devices' support for the IEEE 802.11k protocol. If the client device does not support the IEEE 802.11k protocol, or if it does support the IEEE 802.11k protocol but the measurement report frame sent to the serving AP device is missing some measurement report elements, the network side cannot recommend the optimal target AP device to the client device. Furthermore, the above recommendation mechanism requires frequent communication between the serving AP device and the client device, consuming channel resources and resulting in significant roaming latency, leading to a perceived deterioration in service quality for the user.

[0028] In view of this, this disclosure proposes a wireless communication method performed by a serving AP device, which determines the target AP device to be roamed by the client device based on the communication interaction between the serving AP device and other candidate AP devices in the ESS set when the client device needs to perform wireless roaming, without relying on the client device to perform wireless resource measurement.

[0029] Figure 2 A flowchart illustrating a wireless communication method 200 for an AP device according to an embodiment of the present disclosure is provided.

[0030] like Figure 2 As shown, the wireless communication method 200 according to an embodiment of this disclosure can be executed by a serving AP device currently associated with a client device. The wireless communication method 200 may include: step S201, sending a first request to each of one or more candidate AP devices located in the same extended service set as the serving AP device, the first request instructing each candidate AP device to measure the signal strength from each client device; step S202, receiving a first response from each candidate AP device including the measurement result of the signal strength; step S203, determining, at least based on the first response, a target AP device to which the client device should roam and associate from the one or more candidate AP devices; and step S204, sending a second request to the client device, the second request instructing the client device to roam and associate with the target AP device.

[0031] When a client device associates with an access point (AP) device, it needs to send capability information to the AP device. For example, if the capability information sent by the client device indicates that it does not support the IEEE 802.11k protocol, or if the client device is unable to perform wireless resource measurements due to hardware limitations, the serving AP device may execute wireless communication method 200. Alternatively, if the measurement report frame sent by the client device to the serving AP device based on the 802.11k protocol is missing information, and the serving AP device cannot determine the optimal roaming target AP, the serving AP device may execute wireless communication method 200. This disclosure does not impose any particular limitations on the conditions under which the serving AP device executes wireless communication method 200.

[0032] In this disclosure, the AP device currently associated with the client device and providing communication services is referred to as the serving AP device. One or more other AP devices that are in the same extended service set as the serving AP device are referred to as candidate AP devices. The AP device that the client device will roam to is referred to as the target AP device, which may be one or more selected from the candidate AP devices.

[0033] According to the wireless communication method 200 of this disclosure, when a client device needs to roam, the serving AP device can instruct each candidate AP device within its extended service set to measure the signal strength from the client device. Based on the measurement results received from each candidate AP device, a target AP device is determined from the candidate AP devices, and the information of the determined target AP device is provided to the client device. Therefore, when the client device needs to roam wirelessly, it no longer needs to perform wireless resource measurements on the candidate AP devices according to the measurement request element specified by the serving AP device as defined by the IEEE 802.11k protocol. Instead, the candidate AP devices measure the signal strength transmitted during communication between the client device and the serving AP device. Therefore, even if the client device does not support the IEEE 802.11k protocol, or is unable to perform wireless resource measurements on the candidate AP devices due to its simple hardware implementation, or if the measurement results (measurement report element) reported by the client device based on the IEEE 802.11k protocol are missing information, preventing the serving AP device from determining the target AP device for roaming, the serving AP device can still effectively determine the target AP device based on the measurement results reported by the candidate AP devices. Furthermore, during the process of determining the target AP device, the serving AP device and the client device no longer need to perform various communication interactions as specified by the IEEE 802.11k protocol (such as the sending and receiving of measurement request frames and measurement report frames mentioned above). Therefore, it will not occupy the channel resources of the client device and avoid the degradation of communication quality caused by the client's roaming decision.

[0034] Each candidate AP device measures the signal strength of the client device based on a first request received from the serving AP device. Here, the first request may, for example, instruct the candidate AP device to measure the signal strength of only the first wireless signal received from the client device, or instruct the candidate AP device to measure the signal strength of a preset number of wireless signals, or instruct the candidate AP device to measure the strength of wireless signals received within a preset time period.

[0035] In some embodiments, the first request in step S201 may instruct each candidate AP device to receive frames sent by the client device within a preset time period in order to measure the signal strength. The signal strength measurement result of each candidate AP device is the average of the signal strength of all frames received within the preset time period.

[0036] Specifically, the first request may include, for example, the client device's identification information (e.g., MAC address), channel information, etc. The client device transmits wireless signals during communication. The candidate AP device can identify the client device to monitor based on the received first request, receive the wireless signals transmitted by that client device, and measure the signal strength. This signal strength reflects the quality of the communication link between the candidate AP device and the client device, becoming the basis for determining the client device's roaming target. In some implementations, the signal strength can be, for example, a Received Signal Strength Indication (RSSI). By setting a preset time, it can be ensured that the candidate AP device receives a sufficient number of frames (sent by the client device), thereby ensuring the accuracy of the signal strength measurement results. Furthermore, the candidate AP device only receives and measures the client device's signal strength within the preset time; after the preset time has elapsed, the measurement ends and a first response containing the measurement results is sent. This allows for timely reporting of the signal strength measurement results, avoiding reporting delays caused by constantly monitoring the client device, and preventing the waste of channel resources due to prolonged monitoring of non-serving client devices, thus avoiding impacting the candidate AP device's own communication service.

[0037] In some implementations, the preset time may be, for example, 1 second, but is not limited to this. The candidate AP device calculates the average signal strength of all frames received within the preset time as the signal strength measurement result. In some implementations, each candidate AP device can calculate an exponential moving average (EMA) of the signal strength of all received frames. Furthermore, not limited to EMA, each candidate AP device can also calculate a simple moving average, a weighted moving average, or perform various filtering processes such as Kalman filtering or median filtering. By calculating the average signal strength (or performing filtering), random fluctuations in signal strength can be effectively filtered out, improving the accuracy of the candidate AP device's signal strength measurement. Of course, when only one frame is received, the average here can refer to the signal strength of that frame itself.

[0038] After a candidate AP device obtains the signal strength measurement result from a client device, it can send a first response to the serving AP device. In step S202, the serving AP device can receive the first responses from each candidate AP device. In some embodiments, the first response may include the identification information of the candidate AP device (e.g., the BSSID and MAC address of the candidate AP device) and the corresponding signal strength measurement result obtained by the candidate AP device.

[0039] In step S203, the serving AP device can determine the target AP device from one or more candidate AP devices, at least based on the first response. In some embodiments, the serving AP device can determine the candidate AP device with the best signal strength measurement among the one or more candidate AP devices as the target AP device. For example, when signal strength is represented by RSSI, the serving AP device can determine the candidate AP device with the largest RSSI as the target AP device based on the first responses received from each candidate AP device. This ensures that the signal strength of the target AP device determined by the serving AP device is the best among all candidate APs, guaranteeing communication quality after the client device is associated with roaming.

[0040] After identifying the target AP device, in some embodiments, in step S204, the serving AP device may include information related to the target AP device in a second request and send it to the client device. In some implementations, the second request may, for example, follow the message format specified by the IEEE 802.11v protocol (e.g., BSS Transition Management Request), containing the BSSID of the target AP device (or a list of target AP devices). Upon receiving the second request, the client device may, also based on the IEEE 802.11v protocol, determine whether to roam with the target AP device and send the determination result to the serving AP device. In other implementations, the second request may not follow the IEEE 802.11v protocol but instead use a proprietary protocol message. In this case, the second request may include the identification information (BSSID) of the target AP device.

[0041] In some embodiments, after the serving AP device determines the target AP device in step S203, it may not directly execute step S204, but instead send a second request to the client device in response to the target AP device measuring the signal strength from the client device being greater than the serving AP measuring the signal strength from the client device.

[0042] That is, in some embodiments of this disclosure, in addition to the candidate AP device measuring the signal strength from the client device, the serving AP device can also measure the signal strength from the client device. After determining the target AP device, the serving AP device can compare the signal strength measurement result corresponding to the target AP device with its own measurement result. Only when the target AP device's measurement result is better than its own will it send a second request to the client device. This ensures that the communication link quality of the target AP device is better than that of the serving AP device. Therefore, after the client device roams and associates with the target AP device, it will not trigger roaming again due to the existence of an AP device with a better communication link quality than the roamed serving AP device, reducing the "ping-pong effect".

[0043] After receiving the second request, whether the client roams to the target AP device included in the second request, and the specific association mechanism when determining to roam to the target AP device, can follow the existing IEEE 802.11 series of protocols, and this disclosure does not impose any special limitations on this.

[0044] In some embodiments, the first response from a candidate AP device may include, in addition to identification information and signal strength measurement results, the number of frames received by the candidate AP device within a preset time period. For each candidate AP device, the number of frames received affects the confidence level of the signal strength measurement results. More specifically, if a candidate AP device receives more frames within the preset time period, it means that its signal strength measurement results are extracted from more frames, less affected by extreme or random values, and the measurement results can be considered more reliable. Conversely, if a candidate AP device receives only fewer frames within the preset time period, its signal strength measurement results are extracted from only fewer frames, more affected by extreme or random values, and therefore the measurement results can be considered less reliable. Furthermore, if a candidate AP device receives fewer frames sent by client devices than other candidate AP devices within the same preset time period, it often means that the communication link quality between the candidate AP device and the client device is not the best. Therefore, by including the frame count in the first response, the serving AP device also refers to the number of frames received by each candidate AP device when determining the target AP device, which is beneficial for determining the candidate AP device with the best communication link quality as the target candidate AP device.

[0045] In some embodiments, where the first response also includes a number of frames, the serving AP device determining the target AP device from one or more candidate AP devices based at least on the first response may include: adjusting the signal strength measurement result for each of the one or more candidate AP devices based on the number of frames included in the first response; and determining the candidate AP device with the best adjusted signal strength measurement result as the target AP device.

[0046] In other words, after the serving AP device receives the first response from each candidate AP device, it adjusts the signal strength measurement results of the corresponding candidate AP devices based on the number of frames contained in the first response, and determines the target AP device based on the adjusted signal strength measurement results. Thus, the adjusted signal strength measurement results take into account the number of frames received by the candidate AP devices. For candidate AP devices that receive fewer frames, their corresponding adjusted signal strength measurement results can be worse; conversely, for candidate AP devices that receive more frames, their corresponding adjusted signal strength measurement results can be better. Therefore, by determining the target AP device based on the adjusted signal strength measurement results, the serving AP device can effectively reduce the probability of candidate AP devices receiving fewer frames being identified as the target AP device, ensuring that candidate AP devices with better communication link quality are identified as the target AP device.

[0047] More specifically, in some embodiments, for each of one or more candidate AP devices, the signal strength measurement result is adjusted based on the number of frames included in the first response, including: adjusting the signal strength measurement result to a lower value in response to the number of frames being less than a preset frame number threshold; and keeping the signal strength measurement result unchanged in response to the number of frames being greater than or equal to the preset frame number threshold.

[0048] In some implementations, the preset frame count threshold can be set, for example, based on the average number of frames received by the serving AP device from client devices over a number of preset time periods. As mentioned above, the number of frames received within a preset time period reflects the communication link quality between the client device and the AP device. Therefore, adjusting the signal strength measurement results of each candidate AP device based on such a preset frame count threshold can effectively reduce the probability of candidate AP devices with worse communication link quality than the serving AP device being identified as target AP devices, thus helping to identify target AP devices with better communication link quality than the current serving AP device.

[0049] In other implementations, the preset frame count threshold can be set based on the average number of frames received by each candidate AP device within a preset time period. Adjusting the signal strength measurement results of each candidate AP device based on such a preset frame count threshold can effectively eliminate a portion of candidate AP devices with poor communication link quality from multiple candidate APs, ensuring that the determined target AP device has relatively good communication link quality.

[0050] In addition, the preset frame rate threshold can also be flexibly set based on experience. This disclosure does not impose specific limitations on the setting method of the preset frame rate threshold.

[0051] For each candidate AP device, the serving AP device adjusts the signal strength measurement results of the corresponding candidate AP device based on a preset frame count threshold and the number of frames included in the first response. When the frame count is less than the preset frame count threshold, the lower the frame count, the lower the signal strength measurement results of the corresponding candidate AP device can be adjusted. Conversely, when the frame count is above the preset frame count threshold, the signal strength measurement results of the corresponding candidate AP device do not need to be adjusted.

[0052] Specifically, in some implementations, for each candidate AP device, the weight of the signal strength measurement result can be set based on the ratio of the number of frames included in the first response to a preset frame number threshold, and the product of the signal strength measurement result and the weight can be used as the adjusted signal strength measurement result of the corresponding candidate AP device. For example, for each candidate AP device, the adjusted signal strength measurement result can be calculated using the following formula (1).

[0053] RSSI_adj=RSSI min(Frame_rec / Frame_th, 1.0) (1)

[0054] Where RSSI_adj represents the adjusted signal strength measurement result, RSSI represents the signal strength measurement result included in the first response (i.e., the unadjusted) Frame_rec represents the number of frames included in the first response, Frame_th represents the preset frame number threshold, and min(Frame_rec / Frame_th, 1.0) is used as the weight of the signal strength measurement result.

[0055] Alternatively, in other implementations, a nonlinear function can be introduced to set the weight of the signal strength measurement results. For example, for candidate AP devices with a frame count above a preset frame count threshold, the corresponding signal strength measurement results are not adjusted, while for each candidate AP device with a frame count below the preset frame count threshold, the signal strength measurement results can be adjusted based on the following formula (2).

[0056] RSSI_adj=RSSI (1-exp(-Frame_rec / Coef)) (2)

[0057] Where RSSI_adj represents the adjusted signal strength measurement result, RSSI represents the signal strength measurement result included in the first response (i.e., the unadjusted signal strength), Frame_rec represents the number of frames included in the first response, Coef represents a configurable attenuation coefficient, and (1-exp(-Frame_rec / Coef)) is used as the weight of the signal strength measurement result.

[0058] Alternatively, a penalty value can be set according to the weight of the signal strength measurement result, and the penalty value can be subtracted from the signal strength measurement result to obtain the adjusted signal strength measurement result. For example, for each candidate AP device, the signal strength measurement result can be adjusted based on the following formula (3).

[0059] RSSI_adj=RSSI-Pen_max (1-min(Frame_rec / Frame_th, 1.0)) (3)

[0060] Where RSSI_adj represents the adjusted signal strength measurement result, RSSI represents the signal strength measurement result included in the first response (i.e., the unadjusted) and Pen_max represents a configurable maximum penalty value (in dBm). Frame_rec represents the number of frames included in the first response and Frame_th represents the preset frame number threshold. min(Frame_rec / Frame_th, 1.0) is used as the weight of the signal strength measurement result.

[0061] Those skilled in the art will understand that the above-described method for adjusting the signal strength measurement results is merely an example, and other appropriate methods can also be used to adjust the signal strength measurement results. As long as the above-described principle of "when the frame count is less than a preset frame count threshold, the lower the frame count, the lower the signal strength measurement result of the corresponding candidate AP device is adjusted; conversely, when the frame count is above the preset frame count threshold, the signal strength measurement result of the corresponding candidate AP device is not adjusted" is achieved, it should fall within the scope of this disclosure. Furthermore, not limited to the above, when the number of frames received by a candidate AP device is above the preset frame count threshold, the higher the frame count, the better the signal strength measurement result of the corresponding candidate AP device can be adjusted.

[0062] By setting a preset frame count threshold and adjusting the signal strength measurement results of candidate AP devices based on this threshold, the impact of frame count on the confidence level of signal strength measurement results can be fully considered. Furthermore, for candidate AP devices that receive fewer frames than the preset frame count threshold, the fewer frames received, the lower the corresponding signal strength measurement result is adjusted. This effectively eliminates candidate AP devices with poor communication link quality, ensuring that the target AP device determined by the serving AP device has better communication link quality.

[0063] Alternatively, the signal strength measurement results can be adjusted without relying on a preset frame count threshold. For example, the maximum frame count among all candidate AP devices can be used as the adjustment benchmark. For each candidate AP device, the weight of the signal strength measurement result is set based on the ratio of the frame count included in the first response to the maximum value. The product of the signal strength measurement result and the weight is used as the adjusted signal strength measurement result for the corresponding candidate AP device. This method is similar to equation (1) above, except that Frame_th in equation (1) is replaced with the maximum frame count among all candidate AP devices.

[0064] The above describes the specific method by which the serving AP device determines the target AP device based on the signal strength measurement results of each candidate AP device. In some embodiments, the serving AP device determines the target AP device for which the client device should roam from one or more candidate AP devices, and may also do so based on at least one of the following: device type, channel congestion level, number of associated client devices, queue depth, and the first response mentioned above for each of the one or more candidate AP devices.

[0065] In some implementations, the serving AP device can obtain various information from candidate AP devices within the ESS. These candidate AP devices can be of various types, including general AP devices and AP devices with specific functions such as bridge AP devices and repeater AP devices. For candidate AP devices of bridge AP device or repeater AP device type, roaming association with client devices can be avoided as much as possible. Furthermore, the channel congestion level of the candidate AP device can be considered as channel utilization. For candidate AP devices with high channel utilization, roaming association with client devices can be avoided as much as possible. Similarly, for candidate AP devices with a large number of associated client devices, roaming association with client devices can be avoided as much as possible. For candidate AP devices with large uplink / downlink queue depths, roaming association with client devices can be avoided as much as possible. The serving AP device can employ an appropriate decision mechanism / algorithm to determine the target AP device based on the signal strength measurement results of each candidate AP device, and by comprehensively considering one or more factors such as the candidate AP device type, channel congestion level, number of associated client devices, and queue depth. Therefore, the serving AP device determines the target AP device by combining signal strength with more information. It does not only rely on the signal strength of the candidate AP device at the physical layer, but also comprehensively considers the performance indicators of the candidate AP device at higher layers of the network, thus enabling the determination of a more appropriate target AP device.

[0066] Further integration Figure 3 The wireless roaming process 300 according to an embodiment of the present disclosure will be described. Figure 3 A schematic diagram illustrating a wireless roaming process 300 according to an embodiment of the present disclosure is shown.Figure 3 As shown, the WLAN network includes AP devices 301, 302, and 303, and client device 304. Among them, AP device 301 is associated with client device 304 and becomes the serving AP device, while AP devices 302 and 303 become candidate AP devices for roaming association with client device 304.

[0067] In step S1, the serving AP device 301 sends a first request to candidate AP devices 302 and 302 respectively. In step S2, upon receiving the first request, candidate AP devices 302 and 302 measure the signal strength of client device 304 within a preset time period, and send the signal strength measurement results, the number of frames received from the client, and their own BSSID in a first response to the serving AP device 301. In step S3, the serving AP device 301 adjusts the signal strength measurement results of candidate AP devices 302 and 302 based on the signal strength measurement results and the number of frames received from the first responses from candidate AP devices 302 and 302 respectively, and determines candidate AP device 302 as the target AP device based on the adjusted signal strength measurement results. In step S4, the serving AP device 301 sends a second request containing the identification information of the target AP device 302 to client device 304. In step S5, based on the second request, client device 304 determines that it is roaming and is associated with target AP device 302, and sends a response to serving AP device 301 indicating acceptance of the roaming suggestion. Then, in step S6, client device 304 initiates an authentication request to target AP device 302 based on the IEEE 802.11 protocol, completing the roaming association with target AP device 302. Thus, client device 304 roams from its original serving AP device 301 to the new serving AP device 302. In step S7, the new serving AP device 302 reports the roaming event of client device 304 to the original serving AP device 301. In step S8, the original serving AP device 301 removes client device 304 from the associated client list, releasing network resources. The wireless roaming process 300 ends.

[0068] The wireless communication method of the serving AP device according to embodiments of the present disclosure has been described in detail above. According to the wireless communication method of the present disclosure, the serving AP device can promptly suggest a better target AP device to the client device, reducing packet loss and latency during roaming. Furthermore, since the client device does not need to perform radio resource measurements and provide measurement results during the determination of the target AP device, even if the client device does not support the IEEE 802.11k protocol, or although it supports the IEEE 802.11k protocol, the measurement report frame sent to the serving AP device is missing a portion of the measurement report elements, the serving AP device can still suggest a better target AP device to the client device. Moreover, since frequent communication interactions between the serving AP device and the client device are not required, channel resource occupation can be effectively avoided, ensuring the quality of communication services.

[0069] According to another aspect of this disclosure, an AP device is also provided, comprising: one or more processors; a memory coupled to at least one of the one or more processors; and a computer program stored in the memory, which, when executed by at least one of the one or more processors, causes the AP device to perform a wireless communication method as described above.

[0070] Figure 4 An exemplary block diagram of an AP device 400 according to an embodiment of the present disclosure is shown.

[0071] like Figure 4 As shown, the AP device 400 may include a processor 410 and a memory 420. The processor 410 is communicatively coupled to the memory and is configured to perform the wireless communication method described above.

[0072] Examples of processor 410 include microprocessors, microcontrollers, digital signal processors (DSPs), field-programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various functions described in this disclosure.

[0073] Processor 410 can execute software. Software should be broadly interpreted as instructions, instruction sets, code, code segments, program code, programs, subroutines, software modules, application programs, software applications, software packages, routines, subroutines, objects, executable files, execution threads, procedures, functions, etc., regardless of whether it is referred to as software, firmware, middleware, microcode, hardware description languages, or otherwise. The software may reside on memory 1020.

[0074] Memory 420 may be a non-transitory computer-readable medium. Non-transitory computer-readable media include, for example, magnetic storage devices (e.g., hard disks, floppy disks, magnetic stripes), optical disks (e.g., optical discs (CDs) or digital versatile optical discs (DVDs)), smart cards, flash memory devices (e.g., cards, memory cards, or key drives), random access memory (RAM), read-only memory (ROM), programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), registers, removable disks, and any other suitable medium for storing software and / or instructions that can be accessed and read by a computer. Memory 420 may reside in, be external to, or be distributed across multiple entities including processor 410. Memory 420 may be embodied in a computer program product. For example, a computer program product may include a computer-readable medium in packaging material. Those skilled in the art will recognize how the functionality described throughout this disclosure can be implemented based on the specific application and overall design constraints imposed on the overall system.

[0075] According to another aspect of this disclosure, a computer program product is provided, comprising a computer program that, when executed by a processor of an access point (AP) device, causes the AP device to perform the wireless communication method described above. As an example, the computer program product includes a non-transitory computer-readable storage medium containing program instructions executable by a processor of the AP device. When executed, the program instructions cause the AP device to perform the wireless communication method described above as a serving AP device; details are omitted here for brevity.

[0076] This invention can be a system, method, and / or computer program product at any possible level of integration technical detail. The computer program product may include computer-readable program instructions for causing a processor to perform various aspects of this disclosure.

[0077] It should be noted that the flowcharts and block diagrams in the accompanying drawings illustrate the possible structure, function, and operation of the methods and apparatus according to various embodiments of this application. In this respect, each block in a flowchart or block diagram may represent a module, a program segment, or a portion of code containing at least one executable instruction for implementing a specified logical function. It should also be noted that in some alternative embodiments, the functions described in a block may occur in a different order than those described in the accompanying drawings. For example, two blocks shown consecutively may actually be executed in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, may be implemented by a dedicated hardware system that performs the specified function or operation, or by a combination of dedicated hardware and computer instructions. Furthermore, in this disclosure, terms such as “at least one of A, B, or C,” “one or more of A, B, or C,” “at least one of A, B, and C,” “one or more of A, B, and C,” “A, B, C, or any combination thereof” include any combination of A, B, and / or C, and may include multiple A, multiple B, or multiple C. Terms such as “at least one of A, B or C”, “one or more of A, B or C”, “at least one of A, B and C”, “one or more of A, B and C”, “A, B, C or any combination thereof” can be only A, only B, only C, A and B, A and C, B and C or A, B and C, where any such combination can contain one or more members of A, B or C.

[0078] The various embodiments described in this disclosure are for illustrative purposes and are not intended to be exhaustive or limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope of the described embodiments. The terminology used herein is chosen to best explain the principles of the embodiments, their practical application, or improvements to techniques found in the market, or to enable those skilled in the art to understand the embodiments disclosed herein.

[0079] Throughout the description and claims of this specification, the word “comprising” and variations thereof, such as “comprising” and “including,” means “including, but not limited to,” and are not intended to exclude, for example, other additives, components, integers, or steps. “Exemplary” means “an example of a preferred or ideal implementation and is not intended to convey its indication.” “Like” is not used in a limiting sense but for interpretative purposes.

Claims

1. A wireless communication method for an access point (AP) device, wherein the AP device is a serving AP device currently associated with a client device, the method comprising: Send a first request to each of one or more candidate AP devices located in the same extended service set as the serving AP device, the first request instructing each candidate AP device to measure the signal strength from the client device; Receive a first response from each candidate AP device, including the measurement results of the signal strength. Based at least on the first response, the target AP device to which the client device should roam is determined from the one or more candidate AP devices; as well as A second request is sent to the client device, the second request instructing the client device to roam and associate with the target AP device.

2. The method according to claim 1, wherein, The first request instructs each candidate AP device to receive the frames sent by the client device within a preset time to measure the signal strength; as well as The signal strength measurement result for each candidate AP device is the average of the signal strength of all the frames received within the preset time period.

3. The method according to claim 1, wherein, Based at least on the first response, determining the target AP device for which the client device wants to roam from the one or more candidate AP devices includes: The candidate AP device with the best signal strength measurement result among the one or more candidate AP devices is determined as the target AP device.

4. The method according to claim 2, wherein, The first response from each candidate AP device also includes the number of frames received within the preset time period.

5. The method according to claim 4, wherein, Based at least on the first response, determining the target AP device for which the client device wants to roam from the one or more candidate AP devices includes: For each of the one or more candidate AP devices, the signal strength measurement result is adjusted based on the number of frames included in the first response; and The candidate AP device with the best measured signal strength after adjustment is determined as the target AP device.

6. The method according to claim 5, wherein, For each of the one or more candidate AP devices, adjusting the signal strength measurement based on the number of frames included in the first response includes: In response to the frame number being less than a preset frame number threshold, the smaller the frame number, the lower the measured signal strength value is adjusted; and In response to the number of frames being above the preset frame number threshold, the measurement result of the signal strength remains unchanged.

7. The method according to claim 1, wherein, In response to the target AP device measuring the signal strength from the client device as greater than the serving AP device measuring the signal strength from the client device, the second request is sent to the client device.

8. The method according to claim 1, wherein, Based at least on the first response, determining the target AP device for which the client device wants to roam from the one or more candidate AP devices includes: The target AP device is determined from the one or more candidate AP devices based on at least one of the following: device type, channel congestion level, number of associated client devices, queue depth, and the first response.

9. An access point (AP) device, comprising: One or more processors; Memory coupled to at least one of the one or more processors; as well as A computer program stored in the memory, which, when executed by at least one of the one or more processors, causes the AP device to perform the method according to any one of claims 1 to 8.

10. A computer program product comprising a computer program that, when executed by a processor of an access point (AP) device, causes the AP device to perform the method according to any one of claims 1 to 8.

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