Method, apparatus and system for roaming and handover between wireless local area networks

Abstract

Disclosed are a method, apparatus and system for roaming and handover between wireless local area networks. After sending first-type detection request frames on one scanning channel, a station immediately switches to a working channel, or immediately switches to another scanning channel to send the first-type detection request frames, and receives from associated APs recommended AP information that can be used for roaming and handover of the station, wherein the recommended AP information is associated with one or more candidate APs that can receive the first-type detection request frames on scanning channels. Since the station does not need to wait for a detection response frame on the scanning channels, but acquires from the associated APs the recommended AP information for roaming and handover, the effect of a scanning process on time-sensitive communication can be reduced, and the station can quickly obtain information regarding APs to which the station can be handed over, thereby implementing fast roaming.

Description

Wireless local area network roaming switching method, device and system Technical Field

[0001] The present disclosure relates to the field of wireless local area networks, and in particular to a method, device, and system for roaming handover in a wireless local area network. Background Art

[0002] Wireless communications are widely used in homes, offices, businesses, and entertainment environments. For example, due to improvements in performance and mobility, wireless communications are becoming increasingly prevalent in industry. Unlike consumer products, wireless industrial devices require much lower latency and jitter than high data rates to support time-sensitive communications such as PROFINET. However, due to factors such as break-before-make handover, conventional WLAN technology is inherently unsuitable for time-sensitive industrial applications. When a wireless local area network (WLAN) client roams from one access point (AP) to another, it is unable to send or receive data packets to the network, resulting in significant data packet delay and / or packet loss. Depending on the WLAN network deployment and environmental conditions, the roaming process can sometimes take up to several seconds. This roaming mechanism means that WLAN technology, in its commonly implemented form, cannot provide deterministic communication, and the roaming handover process is lengthy, making it difficult to meet the requirements of time-sensitive communications such as those in industrial applications.

[0003] Summary of the Invention

[0004] In view of the above-mentioned defects in the prior art, the present disclosure proposes a wireless local area network roaming handover method, device and system to achieve fast roaming in a wireless local area network to support time-sensitive communications such as industrial applications.

[0005] A first aspect of the present disclosure provides a wireless local area network roaming switching method applicable to a terminal (STA), the method comprising: sending a first type of probe request frame on each scanning channel during an idle period when the STA does not need to perform data transmission on a working channel and an associated access point (AP) associated with the STA, the first type of probe request frame including identification information of the associated AP and the STA, wherein after sending the first type of probe request frame on a scanning channel, immediately switching to the working channel, or immediately switching to another scanning channel to send the first type of probe request frame; and receiving recommended AP information that can be used for roaming switching of the STA from the associated AP, the recommended AP information being related to one or more candidate APs that can receive the first type of probe request frame on each scanning channel.

[0006] A second aspect of the present disclosure provides a wireless local area network roaming switching method, applicable to an access point (AP), the method comprising: a first associated AP associated with a first terminal (STA) receives a probe response frame regarding the first STA from a first one or more candidate APs, each candidate AP being an AP capable of receiving a probe request frame from the first STA on its working channel; the first associated AP generates first recommended AP information for roaming switching of the first STA based on the probe response frame regarding the first STA from the first one or more candidate APs; and the first associated AP sends the first recommended AP information to the first STA.

[0007] The third aspect of the present disclosure provides a wireless local area network roaming switching method, applicable to an access point (AP), the method comprising: an associated AP associated with a terminal (STA) receives recommended AP information for roaming switching of the STA from a network device, the recommended AP information being related to one or more candidate APs that can receive a first type of probe request frame from the STA on its working channel; and sending the recommended AP information from the associated AP to the STA.

[0008] A fourth aspect of the present disclosure provides a wireless local area network roaming switching method, applicable to an access point (AP), the method comprising: a first AP receiving a probe request frame from a terminal (STA) on its working channel; the first AP determining the type of the probe request frame; and if the type of the probe request frame is the first type, the first AP sending a probe response frame for the probe request frame to an associated AP associated with the STA or a network device communicatively connected to the first AP and the associated AP, the probe response frame being used to generate recommended AP information that can be used for roaming switching of the STA, the recommended AP information being also related to at least one other AP, wherein the at least one other AP is an AP that can receive the probe request frame from the STA on its working channel.

[0009] The fifth aspect of the present disclosure provides a wireless local area network roaming switching method, which is applicable to a network device, and the method includes: the network device obtains a probe response frame of a first one or more candidate APs regarding a first STA, wherein the network device is communicatively connected to a first associated AP associated with the first STA, and each candidate AP is an AP capable of receiving a probe request frame from the first STA on its working channel; the network device generates first recommended AP information that can be used for roaming switching of the first STA based on the probe response frame of the first one or more candidate APs regarding the first STA; and the network device sends the first recommended AP information to the first associated AP.

[0010] A sixth aspect of the present disclosure provides a terminal (STA) in a wireless local area network, the STA including: a sending module configured to send a first type of probe request frame on each scanning channel during an idle period when the STA does not need to perform data transmission on a working channel and an associated access point (AP) associated with the STA, the first type of probe request frame including identification information of the associated AP and the STA, wherein after sending the first type of probe request frame on a scanning channel, the STA is immediately switched to the working channel, or immediately switched to another scanning channel to send the first type of probe request frame; and a receiving module configured to receive recommended AP information that can be used for roaming switching of the STA from the associated AP, the recommended AP information being related to one or more candidate APs that can receive the first type of probe request frame on each scanning channel.

[0011] The seventh aspect of the present disclosure provides an access point (AP) in a wireless local area network, wherein the AP is a first associated AP associated with a first terminal (STA), and the first associated AP includes: a receiving module, configured to receive a probe response frame regarding the first STA from a first one or more candidate APs, each candidate AP being an AP capable of receiving a probe request frame from the first STA on its working channel; a generating module, configured to generate first recommended AP information for roaming switching of the first STA based on the probe response frame regarding the first STA from the first one or more candidate APs; and a sending module, configured to send the first recommended AP information to the first STA.

[0012] The eighth aspect of the present disclosure provides an access point (AP) in a wireless local area network, wherein the AP is associated with a terminal (STA), and the AP includes: a receiving module configured to receive recommended AP information for roaming switching of the STA from a network device, wherein the recommended AP information is related to one or more candidate APs that can receive a first type of probe request frame from the STA on its working channel; and a sending module configured to send the recommended AP information to the STA.

[0013] A ninth aspect of the present disclosure provides a first access point (AP) in a wireless local area network, the first AP comprising: a receiving module configured to receive a probe request frame from a terminal (STA) on its working channel; a determining module configured to determine the type of the probe request frame; and a sending module configured to send a probe response frame for the probe request frame to an associated AP associated with the STA or a network device communicatively connected to the first AP and the associated AP if the type of the probe request frame is a first type, the probe response frame being used to generate recommended AP information that can be used for roaming switching of the STA, the recommended AP information being also related to at least one other AP, wherein the at least one other AP is an AP that can receive the probe request frame from the STA on its working channel.

[0014] The tenth aspect of the present disclosure provides a network device, comprising: an acquisition module configured to acquire a probe response frame of a first one or more candidate APs regarding a first STA, wherein the network device is communicatively connected to a first associated AP associated with the first STA, and each candidate AP is an AP capable of receiving a probe request frame from the first STA on its working channel; a generation module configured to generate first recommended AP information that can be used for roaming switching of the first STA based on the probe response frame of the first one or more candidate APs regarding the first STA; and a sending module configured to send the first recommended AP information to the first associated AP.

[0015] The eleventh aspect of the present disclosure provides a terminal (STA) in a wireless local area network, the STA comprising: a communication unit; and a processing unit operably coupled to the communication unit; wherein the communication unit and the processing unit are configured to execute the wireless local area network roaming switching method according to the first aspect described above.

[0016] The twelfth aspect of the present disclosure provides an access point (AP) in a wireless local area network, wherein the AP is a first associated AP associated with a first terminal (STA), and the first associated AP includes: a communication unit; and a processing unit operably coupled to the communication unit; wherein the communication unit and the processing unit are configured to execute the wireless local area network roaming switching method according to the aforementioned second aspect or third aspect.

[0017] The thirteenth aspect of the present disclosure provides a first access point (AP) in a wireless local area network, the first AP comprising: a communication unit; and a processing unit operably coupled to the communication unit; wherein the communication unit and the processing unit are configured to execute the wireless local area network roaming switching method according to the aforementioned fourth aspect.

[0018] The fourteenth aspect of the present disclosure provides a network device, comprising: a communication unit; and a processing unit operably coupled to the communication unit; wherein the communication unit and the processing unit are configured to execute the wireless local area network roaming switching method according to the aforementioned fifth aspect.

[0019] The fifteenth aspect of the present disclosure provides a wireless local area network roaming switching system, the system including multiple access points (APs) and a first terminal (STA), the multiple APs including a first associated AP associated with the first STA, and first one or more candidate APs included in the multiple APs, each of the first one or more candidate APs is an AP capable of receiving a probe request frame from the first STA on its working channel, the first STA is used to execute the wireless local area network roaming switching method according to the first aspect, each of the first one or more candidate APs is used to execute the wireless local area network roaming switching method according to the fourth aspect, and the first associated AP is used to execute the wireless local area network roaming switching method according to the second aspect.

[0020] The sixteenth aspect of the present disclosure provides a wireless local area network roaming switching system, the system including multiple access points (APs), a first terminal (STA) and a network device, the multiple APs including a first associated AP associated with the first STA, and a first one or more candidate APs included in the multiple APs, each of the first one or more candidate APs being an AP capable of receiving a probe request frame from the first STA on its working channel, the STA being used to execute the wireless local area network roaming switching method according to the first aspect, each of the first one or more candidate APs being used to execute the wireless local area network roaming switching method according to the fourth aspect, the first associated AP being used to execute the wireless local area network roaming switching method according to the third aspect, and the network device being used to execute the wireless local area network roaming switching method according to the fifth aspect.

[0021] The seventeenth aspect of the present disclosure provides a computer-readable storage medium, on which computer-executable instructions are stored. When the computer-executable instructions are executed by a processor, the wireless local area network roaming switching method described in the first, second, third, fourth or fifth aspect is implemented.

[0022] The eighteenth aspect of the present disclosure provides a computer program product, which includes computer-executable instructions. When the computer-executable instructions are executed by a processor, the wireless local area network roaming switching method described in the first, second, third, fourth or fifth aspect is implemented.

[0023] Through the technical solutions provided by the various embodiments of the present disclosure, the impact of the long waiting time of the traditional scanning process on time-sensitive communications can be reduced by eliminating the need for each terminal to wait for a response after channel scanning, and each terminal can quickly and globally obtain information about the APs that can be switched to in the wireless local area network to achieve fast and better roaming. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The preferred embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings, so that those skilled in the art will have a better understanding of the above and other features and advantages of the present disclosure. In the accompanying drawings:

[0025] FIG1 is a schematic diagram of a wireless roaming handover system according to an embodiment of the present disclosure;

[0026] FIG2 is a flowchart of a first exemplary wireless roaming handover method according to an embodiment of the present disclosure;

[0027] FIG3 is a flowchart of a second exemplary wireless roaming handover method according to an embodiment of the present disclosure;

[0028] FIG4 is a flowchart of a third exemplary wireless roaming handover method according to an embodiment of the present disclosure;

[0029] FIG5 is a flowchart of a fourth exemplary wireless roaming handover method according to an embodiment of the present disclosure;

[0030] FIG6 is a flowchart of a fifth exemplary wireless roaming handover method according to an embodiment of the present disclosure;

[0031] FIG7 is a schematic structural diagram of an exemplary terminal STA in a wireless local area network according to an embodiment of the present disclosure;

[0032] FIG8 is a schematic structural diagram of an exemplary access point AP in a wireless local area network according to an embodiment of the present disclosure;

[0033] FIG9 is a schematic structural diagram of another exemplary access point AP in a wireless local area network according to an embodiment of the present disclosure;

[0034] FIG10 is a schematic structural diagram of another exemplary access point AP in a wireless local area network according to an embodiment of the present disclosure;

[0035] FIG11 is a schematic structural diagram of an exemplary network device according to an embodiment of the present disclosure;

[0036] FIG12 is a block diagram of an exemplary terminal STA according to an embodiment of the present disclosure;

[0037] FIG13 is a block diagram of an exemplary access point AP according to an embodiment of the present disclosure;

[0038] FIG14 is a block diagram of another exemplary access point AP according to an embodiment of the present disclosure; and

[0039] FIG15 is a block diagram of an exemplary network device in a wireless local area network according to an embodiment of the present disclosure.

[0040] The accompanying drawings are numerals as follows:

[0041] 100: Wireless LAN roaming system 101A-101E: Terminal STA 102A-102F: Access point AP

[0042] 103: First network device 104: Second network device

[0043] 700: Terminal STA 701: Sending module 702: Receiving module

[0044] 800: Associated AP 801: Receiving module 802: Generating module

[0045] 803: Sending module

[0046] 900: Associated AP 901: Receiving module 902: Sending module

[0047] 1000: First AP 1001: Receiving module 1002: Determining module

[0048] 1100: Network device 1101: Acquisition module 1102: Generation module

[0049] 1103: Sending module

[0050] 1200: Terminal STA 1201: Communication unit 1202: Processing unit

[0051] 1300: Associated AP 1301: Communication unit 1302: Processing unit

[0052] 1400: First AP 1401: Communication unit 1402: Processing unit

[0053] 1500: Network device 1501: Communication unit 1502: Processing unit DETAILED DESCRIPTION

[0054] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention is further described in detail below through various embodiments.

[0055] In this application, a terminal STA refers to a device equipped with WLAN functionality, and may also be interchangeably referred to as a station, mobile station (MS), or client. An associated AP refers to the AP to which the STA is currently associated, and which transmits data with the STA on a working channel, such as beacon frames, management frames, or control frames in the 802.11 standard protocol.

[0056] The technical solutions provided by the various embodiments of this disclosure can be applied in mobile communications scenarios, particularly WLAN networks. Due to the limited signal coverage of a single AP, multiple APs are typically deployed to meet signal coverage requirements in scenarios such as homes, offices, businesses, industries, and entertainment. When STAs move within a WLAN, they often cross from one AP's service area to another. Therefore, STAs may need to switch from one AP to another to achieve wireless roaming.

[0057] In a WLAN network, a complete handover process can generally be divided into three phases: scanning, authentication, and reassociation. For the scanning phase, the IEEE 802.11 standard provides two scanning mechanisms: passive scanning and active scanning. In passive scanning, a STA listens for beacon frames sent by an AP on different channels, with the default beacon frame interval typically being approximately 100ms. In active scanning, a STA sends (e.g., broadcasts) Probe Request frames on different channels. If the STA receives a response (e.g., a Probe Response frame) or any traffic transmission from an AP within the MinChannelTime, it waits for the MaxChannelTime to obtain further responses from other APs on the same channel. Otherwise, the channel is considered empty and the channel scan is completed. Compared to passive scanning, active scanning reduces scanning time but increases traffic load and power consumption. However, the MaxChannelTime is typically configured to be at least 10ms. Therefore, even for time-sensitive industrial applications, the time consumption of active scanning can still be unacceptable, especially when scanning multiple channels. After scanning all channels, the STA selects an AP to associate with based on information from all available APs. Typically, the scanning phase is the most time-consuming phase of the roaming process, accounting for over 90% of the total roaming latency. Therefore, regardless of whether active or passive scanning is used, the scanning phase during the handover process will result in significant latency, impacting data transmission between the STA and the associated AP. For example, if a STA spends too much time waiting to scan, it may miss data transmitted between the STA and the associated AP on the working channel. This can make it difficult to meet industrial latency / jitter requirements in time-sensitive industrial applications, and can even have disastrous consequences.

[0058] For example, to speed up the roaming process, a client supporting standard 802.11k sends a request to the AP to obtain a list of neighboring APs (i.e., only APs operating on the same channel as the associated AP) to save some scanning time. Standard 802.11r reduces the re-authentication and association information exchange steps by using the FT (Fast BSS Transition) function. However, most existing WLAN products do not support fast roaming, especially for industrial application scenarios such as time-sensitive communications.

[0059] In view of this, the following embodiments effectively improve STA roaming switching by significantly reducing the time of the scanning phase. Specifically, the present disclosure provides a network-assisted roaming solution for WLAN to achieve fast switching between APs, and also has some additional new features. By introducing a "Roaming Management Unit (RMU)" module into the network architecture. The RMU can be a dedicated hardware device, or can be implemented as a software application running on a general-purpose computing device (for example, an edge device, a server, or even a computing resource resident in an AP, or other network device, etc.), or a combination thereof. Unlike the prior art, when each terminal sends a probe request frame on a scanning channel, it does not wait for the AP's probe response frame on the scanning channel. Instead, the RMU collects each terminal's probe response frame from the AP to generate recommended AP information and transmits the recommended AP information to the associated AP associated with each terminal, thereby significantly reducing the time of the scanning process. That is, the RMU globally collects information about available APs for each terminal and generates recommended AP information for each terminal based on the information about available APs, as described below in conjunction with Figures 1 to 15 regarding the various embodiments of the present disclosure.

[0060] FIG1 shows a schematic diagram of a wireless roaming handover system 100 according to an embodiment of the present disclosure. System 100 includes multiple terminals STA 101A-101E (collectively referred to as STA 101) and multiple APs 102A-102F (collectively referred to as AP 102), which form a WLAN architecture. STA 101 may be a WLAN-enabled mobile phone, tablet computer, laptop computer, wearable device, portable tool, or an automated guided vehicle (AGV) equipped with a WLAN device. AP 102 may be a network device that supports WLAN functionality. For example, AP 102 may be a wireless switch, router, or other network device configured to provide wireless access services based on a WLAN protocol (e.g., an 802.11 standard protocol) to terminal 101. It should be understood that the number of STAs and APs in FIG1 is for illustrative purposes only and does not limit the WLAN provided by the embodiments of the present disclosure. A WLAN may include a greater or lesser number of STAs and APs, and each AP may include a greater or lesser number of associated STAs.

[0061] The available frequency band in a WLAN can be divided into channels. For example, the 2.4 GHz frequency band is divided into multiple overlapping, staggered 20 MHz channels, and the 5 GHz frequency band is divided into multiple non-overlapping 20 MHz channels. Typically, a limited set of channels in a WLAN is shared by a large number of APs, which inevitably leads to severe co-channel interference (CCI) between APs using the channels. To improve the performance of data transmission in a WLAN, channel allocation (e.g., inter-frequency allocation, etc.) must be considered with CCI, such that adjacent APs use channels of different frequencies. For example, in the WLAN architecture of FIG1 , STA 101A is associated with AP 102A (as indicated by the dotted line). Some of the other APs 102B-102F that are closer to AP 102A may operate on different channels from AP 102A, while some that are farther away from AP 102A may operate on the same channel as AP 102A. Similarly, as indicated by the dashed lines, STA 101B is associated with AP 102B, and STA 101C is associated with AP 102C. AP 102 may be associated with more or fewer STAs 101, for example, AP 102D is associated with STAs 101D and 101E, and APs 102E and 102F are not associated with any STAs.

[0062] Optionally, multiple APs 102 can be communicatively connected. As shown in Figure 1, the system 100 (specifically, the WLAN architecture therein) also includes a first network device 103, and multiple APs 102 can be connected through the first network device 103. For example, the first network device 103 can be a network connection device such as a switch, a router, a hub, a network management device such as a wireless controller, or other network devices. For example, the AP 102 can be connected to the first network device 103 via a wired connection or wirelessly connected to the first network device 103 that supports wireless functions. Alternatively, the APs 102 can also be directly communicatively connected via a wired connection or a wireless connection. Alternatively, the WLAN may not include a wireless controller, for example, the AP 102 can directly access other types of networks.

[0063] Optionally, the system 100 may further include a second network device 104, which may be connected to the WLAN directly or indirectly (e.g., via another network, etc.) to communicate with the AP 102. For example, as shown in FIG1 , the second network device 104 may be communicatively connected to the first network device 103 to communicate with the AP 102. Alternatively, the second network device 104 may be connected to the WLAN to communicate with the AP 102 in other ways.

[0064] The RMU provided by the present disclosure may be implemented on any one of the AP 102 , the first network device 103 , and the second network device 104 in FIG. 1 in a hardware manner, a software manner, or a combination thereof.

[0065] FIG2 is a flowchart illustrating a first exemplary wireless roaming handover method 200 according to an embodiment of the present disclosure. Method 200 may be applicable to WLAN roaming handover system 100 or WLAN of FIG1 , and may be performed by, for example, STA 101 of FIG1 , STA 700 of FIG7 , or STA 1200 of FIG12 . As shown in FIG2 , method 200 includes steps 201 to 202.

[0066] In step 201, during an idle period when a terminal STA does not need to perform data transmission on a working channel with an associated access point (AP) associated with the STA, the terminal STA transmits a first-type probe request frame on each scanning channel. The first-type probe request frame includes identification information of the associated AP and the STA. After transmitting the first-type probe request frame on a scanning channel, the STA immediately switches to the working channel or immediately switches to another scanning channel to transmit the first-type probe request frame. In this step, after issuing a probe request, the STA (e.g., STA 101 in FIG. 1 ) immediately switches back to its working channel or continues scanning on another channel (i.e., a scanning channel different from the working channel) without any waiting, thereby significantly reducing scanning time during roaming. In addition, the STA can periodically switch to another channel during idle time to broadcast probe request frames without interfering with normal data transmission due to the short scanning time.

[0067] Optionally, the STA may receive (e.g., listen to) beacon frames from other APs operating on the same channel as the associated AP on the working channel to obtain relevant information about the neighboring APs (e.g., AP basic information, AP quality information, etc.). Alternatively, the STA may also send a first-type probe request frame on the working channel. Since the first-type probe request frame is used for channel scanning, the associated AP may ignore it upon receiving the probe request frame. Alternatively, the associated AP may send relevant information about the neighboring APs on the same channel (e.g., AP basic information, AP quality information, etc.) in response to the probe request frame. Alternatively, the STA may wait for a probe response frame from the neighboring AP on the working channel and not wait for any probe request frame on the scanning channel.

[0068] Alternatively, a STA can send a probe request frame on all enabled scanning channels to discover APs available for STA switching on all channels. Alternatively, a STA can select one or more scanning channels from multiple scanning channels for scanning based on its own resource usage, power usage, etc.

[0069] In step 202, the STA receives recommended AP information from the associated AP for roaming handover. The recommended AP information is associated with one or more candidate APs that can receive first-type probe request frames on various scanning channels. In this step, the STA does not need to wait for probe response frames from the candidate APs on the scanning channels to determine a suitable AP for handover. Instead, the STA obtains recommended AP information associated with the candidate APs from the associated AP, thereby saving the time required to wait for probe request frames and the power required to process probe request frames. For example, the recommended AP information may indicate a preferred AP for roaming selection. For example, the STA may store the recommended AP information received at each moment and update the stored recommended AP information over time when updated recommended AP information is received from the associated AP.

[0070] Optionally, the recommended AP information may also be related to neighbor APs operating on the same channel as the associated AP. For example, the associated AP may obtain (e.g., from the associated STA (e.g., by receiving information about neighbor APs sent by the STA), or from the associated AP in other ways) information about neighbor APs operating on the same channel (e.g., basic AP information, AP quality information, etc.).

[0071] Optionally, the recommended AP information is generated based on the STA's probe response frames from the one or more candidate APs. That is, the recommended AP information can be generated based on responses from APs across the entire WLAN that can receive the STA's probe request frames, thereby discovering APs available for STA handover on all channels. For example, the recommended AP information can be generated based on the probe response frames from all candidate APs for the STA, and can contain richer information than a single probe response frame, as described below.

[0072] Optionally, the recommended AP information is associated with a recommended AP set determined from the one or more candidate APs based on AP quality information included in the probe response frames of the one or more candidate APs regarding the STA. The recommended AP information includes basic AP information and AP quality information of the recommended AP set. The basic AP information includes AP identification information and channel information. For example, the AP identification information may include, but is not limited to, a basic service set identifier (BSSID), a MAC address, or other information that uniquely identifies an AP in a WLAN. For example, the channel information may include the AP's current operating channel. For example, to optimize AP switching, the recommended AP information may be selected from APs discovered on all channels that are available for STA switching based on the AP quality information, thereby saving processing power associated with the STA's AP selection. For example, compared to conventional probe response frames, the probe response frames regarding the STA from the one or more candidate APs may include additional information, including, but not limited to, basic STA information (e.g., the STA's MAC address, the STA's associated AP, etc.), AP quality information of the candidate APs, and the like.

[0073] Optionally, the recommended AP information may also be generated based on relevant information of neighboring APs operating on the same channel as the associated AP.

[0074] Optionally, method 200 may further include: in response to receiving an indication to perform AP switching from an associated AP, determining an AP to which the STA is to switch based on the recommended AP information. In some cases, the associated AP may proactively request the STA to switch. For example, the STA may receive an indication to perform AP switching from the associated AP (e.g., when the associated AP makes a decision to request the STA to switch based on its own load status, signal strength, signal-to-interference ratio, etc., or based on a comparison of its own load status, signal strength, signal-to-interference ratio, etc. with that of other APs), and determine the target AP to switch to based on the recommended AP information provided by the associated AP.

[0075] Optionally, method 200 may further include: the STA obtaining AP quality information of an associated AP; the STA determining whether to perform AP switching based on the AP quality information of the associated AP and the recommended AP set; and if the STA determines to perform AP switching, determining the AP to which the STA is to switch based on the recommended AP information. In some cases, the STA may proactively determine whether to switch from the associated AP to another AP. For example, the STA may obtain AP quality information from the associated AP (e.g., by listening to beacon frames or requesting the associated AP to transmit AP quality information). The STA may also receive AP quality information of the recommended AP set included in the recommended AP information from the associated AP. The STA may then determine whether to perform AP switching based on the associated AP's AP quality information or a comparison of the associated AP's AP quality information with the AP quality information of the recommended AP set. For example, if the STA discovers that the associated AP is deteriorating (e.g., excessive load, decreased signal strength or signal-to-interference ratio, rejection of new STAs, etc.) or discovers an AP that is better than the associated AP, the STA may determine the target AP to switch to based on the recommended AP information. For example, AP quality information may include, but is not limited to, AP load status, AP signal strength (e.g., RSSI with a STA), AP signal-to-interference ratio (e.g., SNR with a STA), information indicating whether the AP rejects or allows a new STA, or a combination thereof.

[0076] Optionally, method 200 may further include: obtaining AP signal strengths of a recommended AP set or one or more candidate APs; and determining the STA's location in the wireless local area network based on the obtained AP signal strengths. For example, the STA may obtain the AP signal strengths of all available APs on all channels from an associated AP, or obtain the AP signal strengths of APs with better signal quality from an associated AP, thereby more accurately determining the STA's location in the local area network and implementing positioning.

[0077] Optionally, method 200 may further include: sending a second type of probe request frame on an available channel before the STA first associates with an AP in the wireless local area network; and after sending the second type of probe request frame, the STA waits for a probe response frame on an available channel. In some cases, the candidate AP still responds to the STA with a probe response on its operating channel, even though the STA does not receive it, so that the STA's first association with an AP in the WLAN is not affected. In other cases, different types of probe request frames may be sent to distinguish between channel scanning for roaming and channel scanning for first association. For example, first association and roaming from one AP to another can be distinguished by taking some measures (one approach is to utilize a reserved bit in the probe request frame, or other approaches (e.g., different frame lengths, additional frame type indication flags, etc.)). Therefore, the candidate AP does not send back a probe response to the STA for channel scanning during roaming, but still sends a probe response to the STA for first association.

[0078] Figure 3 illustrates a flowchart of a second exemplary wireless roaming handover method 300 according to an embodiment of the present disclosure. Method 300 may be applicable to the WLAN roaming handover system 100 or WLAN of Figure 1 and may be performed, for example, by AP 102 of Figure 1 , AP 800 of Figure 8 , or AP 1300 of Figure 13 . As shown in Figure 3 , method 300 includes steps 301 to 303. In method 300, the RMU may be integrated into the associated AP via hardware, software, or a combination thereof.

[0079] In step 301, a first associated AP associated with a first terminal STA receives a probe response frame for the first STA from one or more first candidate APs. Each candidate AP is an AP capable of receiving probe request frames from the first STA on its operating channel. For example, associated AP 102A associated with STA 101 in FIG1 receives corresponding probe response frames from other APs 102 capable of receiving probe request frames for channel scanning sent by STA 101. For example, associated AP 102A may receive corresponding probe response frames from other APs 102 via a wired connection to conserve air interface resources, or may receive corresponding probe response frames from other APs 102 wirelessly to avoid various wired connections. Alternatively, the candidate APs may be a subset of all APs capable of receiving probe request frames from the STA on their operating channel. For example, some APs may refuse to respond to probe request frames based on their own AP quality information. For example, compared with a conventional probe response frame, the probe response frame regarding the first STA from the first one or more candidate APs may include additional information, including but not limited to the STA basic information of the first STA (for example, the MAC address of the STA, the associated AP of the STA, etc.), AP quality information of the candidate AP, etc.

[0080] In step 302, the first associated AP generates first recommended AP information for roaming handover of the first STA based on probe response frames from one or more first candidate APs regarding the first STA. Specifically, the first recommended AP information can be generated based on responses from APs across the entire WLAN that can receive the STA's probe request frames, thereby enabling discovery of APs available for handover on all channels. For example, the recommended AP information can be generated based on probe response frames from all candidate APs for the STA and can contain richer information than a single probe response frame. For example, AP 102A can generate recommended AP information for STA 101A based on probe response frames received from one or more candidate APs regarding STA 101A.

[0081] In step 303, the first associated AP sends first recommended AP information to the first STA. In this step, the first associated AP provides the first STA with recommended AP information related to candidate APs, saving the STA time waiting for probe request frames and power required to process them. For example, the recommended AP information can indicate a preferred AP for roaming selection. For example, AP 102A sends the generated recommended AP information to associated STA 101A.

[0082] Optionally, step 302 may include: determining a first recommended AP set from the first one or more candidate APs based on AP quality information included in a probe response frame of the first one or more candidate APs regarding the first STA; and generating first recommended AP information based on AP basic information and AP quality information of the first recommended AP set, wherein the AP basic information includes AP identification information and channel information. For example, the AP identification information may include, but is not limited to, a basic service set identifier (BSSID), a MAC address, or other information that uniquely identifies an AP in a WLAN. For example, the channel information may include the AP's current operating channel. For example, the AP quality information may include, but is not limited to, AP load status, AP signal strength (e.g., RSSI with a STA), AP signal-to-interference ratio (e.g., SNR with a STA), information indicating whether the AP rejects or allows a new STA, or a combination thereof.

[0083] Optionally, the first associated AP can also obtain (for example, obtain from the associated STA (for example, receive relevant information of the neighbor AP sent by the STA), the first associated AP obtains in other ways) AP quality information of the neighbor AP operating on the same channel as it, and determine a first recommended AP set from the neighbor AP and the first one or more candidate APs based on the AP quality information of the neighbor AP and the candidate AP.

[0084] Optionally, method 300 may also include: the first associated AP may determine whether to cause the first STA to perform AP switching based on the AP quality information of the first associated AP and the first recommended AP set; in response to determining that the first STA is to perform AP switching, sending an indication to perform AP switching to the first STA, as described above with respect to method 200.

[0085] Optionally, the method 300 may further include: in response to the first associated AP determining that the first STA is to perform AP handover or receiving an indication from the first STA that the first STA is to perform AP handover, the first associated AP sharing (for example, transmitting the handshake message to the AP in the first recommended AP set via a wired or wireless manner, or the first associated AP storing the handshake message in a storage device and providing an access address to the AP in the first recommended AP set, etc.) a handshake message regarding an authentication process between the first associated AP and the first STA. For example, by sharing the handshake message regarding the authentication process, the authentication process between the AP in the first recommended AP set and the first STA may be simplified or even eliminated, thereby further reducing the time required for roaming handover.

[0086] Optionally, method 300 may further include: the first associated AP receiving a probe response frame regarding the second STA from one or more second candidate APs, each candidate AP being an AP capable of receiving probe request frames from the second STA on its operating channel; the first associated AP generating, based on the probe response frame regarding the second STA from the one or more second candidate APs; and the first associated AP sending, to the second associated AP associated with the second STA, the second recommended AP information. Similarly, compared to conventional probe response frames, the probe response frame regarding the second STA from the one or more second candidate APs may include additional information, including but not limited to basic STA information of the second STA (e.g., MAC address of the STA, associated AP of the STA, etc.), AP quality information of the candidate APs, etc. For example, AP 102A may receive probe response frames regarding one or more candidate APs of STA 101B, generate corresponding recommended AP information for roaming handover of STA 101B based on these probe response frames (e.g., analyzing information included in the probe response frames, etc.), and send the corresponding recommended AP information to AP 102B associated with STA 101B. Similarly, AP 102A may receive probe response frames of candidate APs for each STA 101 in the WLAN and generate corresponding recommended AP information for each STA 101 based on the probe response frames.

[0087] In the method 300, the first associated AP integrated with the RMU can obtain the probe response frame of the candidate AP of each STA, and generate recommended AP information for each STA based on the probe response frame. Therefore, the first associated AP can realize global management of the switchable APs of all STAs in the WLAN, and send recommended AP information related to the STA corresponding to the other associated APs to other associated APs.

[0088] FIG4 illustrates a flowchart of a third exemplary wireless roaming handover method 400 according to an embodiment of the present disclosure. Method 400 may be applicable to the WLAN roaming handover system 100 or WLAN of FIG1 , and may be performed by, for example, AP 102A of FIG1 , AP 900 of FIG9 , or AP 1300 of FIG13 . As shown in FIG4 , method 400 includes steps 401-402. In method 400, the RMU may be integrated into a network device different from the associated AP via hardware, software, or a combination thereof.

[0089] In step 401, an associated AP associated with a terminal STA receives recommended AP information for roaming handover of the STA from a network device. The recommended AP information is related to one or more candidate APs that can receive a first type of probe request frame from the STA on its working channel.

[0090] In step 402, recommended AP information is sent from the associated AP to the STA.

[0091] Optionally, the recommended AP information is generated based on probe response frames regarding the STA from one or more candidate APs, as described above with respect to methods 200 and 300 .

[0092] Optionally, the recommended AP information is related to a recommended AP set determined from one or more candidate APs based on AP quality information included in a probe response frame of the one or more candidate APs regarding the STA, and the recommended AP information includes AP basic information and AP quality information of the recommended AP set, and the AP basic information includes identification information and channel information of the AP, as described above with respect to methods 200 and 300.

[0093] Optionally, the recommended AP information may also be related to neighbor APs operating on the same channel as the associated AP. For example, the associated AP may obtain (e.g., from an associated STA (e.g., by receiving information about neighbor APs sent by the STA), or from the associated AP in other ways) information about neighbor APs operating on the same channel (e.g., basic AP information, AP quality information, etc.), as described above with respect to method 300.

[0094] Optionally, method 400 may further include: determining whether to enable the STA to perform AP switching based on AP quality information of the associated AP and the recommended AP set; and sending an indication to the STA to perform AP switching in response to determining that the STA is to perform AP switching, as described above with respect to method 300.

[0095] Optionally, method 400 may further include: in response to determining that the STA is to perform AP switching or receiving an indication from the STA that the STA is to perform AP switching, sharing a handshake message regarding the authentication process between the associated AP and the STA with an AP in the recommended AP set, as described above with respect to method 300.

[0096] Optionally, the network device is a device in the wireless local area network that is different from the associated AP and the STA, a device that is different from all APs and the STA, or a device outside the wireless local area network. For example, taking the WLAN in FIG1 as an example, the network device integrated with the RMU can be a device in the WLAN other than the STA 101 and the AP 102A associated with the STA 101, such as any one of the APs 102B-102F, the first network device 103, or the second network device 104, or any one of the first network device 103 and the second network device 104. The second network device 104 can be a device in the WLAN or a device outside the WLAN.

[0097] FIG5 is a flowchart illustrating a fourth exemplary wireless roaming handover method 500 according to an embodiment of the present disclosure. Method 500 may be applicable to the WLAN roaming handover system 100 or WLAN of FIG1 , and may be performed by, for example, an AP among APs 102B-102F of FIG1 , AP 1000 of FIG10 , or AP 1400 of FIG14 . As shown in FIG5 , method 500 includes steps 501-503. In method 500, the RMU may be integrated into the associated AP or into a network device separate from the associated AP via hardware, software, or a combination thereof.

[0098] In step 501, a first AP receives a probe request frame from a terminal STA on its working channel. As described above, the first AP is one of the candidate APs of the STA.

[0099] In step 502, the first AP determines the type of the probe request frame. In this step, the first AP determines whether the probe request frame is for channel scanning for roaming or for a WLAN associated for the first time.

[0100] In step 503, if the probe request frame is of the first type, the first AP sends a probe response frame in response to the probe request frame to an associated AP associated with the STA or a network device communicatively connected to the first AP and the associated AP. The probe response frame is used to generate recommended AP information for roaming handover of the STA. The recommended AP information is also associated with at least one other AP, where the at least one other AP is an AP capable of receiving the probe request frame from the STA on its operating channel. In this step, the first AP sends a probe response frame in response to the STA's probe request frame to the network device instead of responding to the STA on its operating channel, thereby reducing the STA's scanning waiting time. The recommended AP information generated using the probe response frame is associated with the first AP and other candidate APs.

[0101] Optionally, the recommended AP information may also be related to neighbor APs operating on the same channel as the associated AP. For example, the associated AP may obtain (e.g., from an associated STA (e.g., by receiving information about neighbor APs sent by the STA), or from the associated AP in other ways) information about neighbor APs operating on the same channel (e.g., basic AP information, AP quality information, etc.), as described above with respect to method 300.

[0102] Optionally, before the first AP sends the probe response frame, the associated AP is determined according to the identification information of the associated AP included in the probe request frame from the STA, so as to send the probe response frame to the associated AP or a network device communicatively connected to the associated AP.

[0103] Optionally, if the type of the probe request frame is the second type, the first AP sends a probe response frame to the STA in response to the probe request frame, so that the STA associates with the WLAN for the first time, as described above with respect to method 200 .

[0104] FIG6 is a schematic flow diagram of a fifth exemplary wireless roaming handover method 600 according to an embodiment of the present disclosure. Method 600 can be applied to the WLAN roaming handover system 100 or WLAN of FIG1 , and can be performed by, for example, an AP among APs 102B-102F of FIG1 , the first network device 103 or the second network device 104 of FIG1 , the AP 1100 of FIG11 , or the network device 1500 of FIG15 . As shown in FIG6 , method 600 includes steps 601-603. In method 600, the RMU can be integrated into the network device via hardware, software, or a combination thereof.

[0105] In step 601, a network device obtains probe response frames from one or more first candidate APs regarding a first STA. The network device is communicatively connected to a first associated AP associated with the first STA, and each candidate AP is an AP capable of receiving probe request frames from the first STA on its operating channel. In some cases, the network device may be a candidate AP for the first STA, receiving probe response frames from the first STA and probe response frames regarding the first STA from other candidate APs for the first STA in the WLAN (e.g., probe request frames sent to candidate APs for the first STA). In other cases, the network device may not be a candidate AP for the first STA, receiving probe response frames regarding the STA from all candidate APs for the first STA (e.g., probe request frames sent to candidate APs for the first STA). For example, compared to a conventional probe response frame, the probe response frames from the one or more first candidate APs regarding the first STA may include additional information, including but not limited to basic STA information of the first STA (e.g., the MAC address of the STA, the STA's associated AP, etc.), AP quality information of the candidate APs, and the like.

[0106] In step 602, the network device generates first recommended AP information that can be used for roaming handover of the first STA based on the probe response frames of the first one or more candidate APs for the first STA. For example, the network device can generate the recommended AP information in a manner similar to that described above regarding the associated AP in method 300. For example, the first recommended AP information can be generated based on the probe response frames of all candidate APs for the first STA and can contain richer information than a single probe response frame.

[0107] In step 603, the network device sends first recommended AP information to the first associated AP. By feeding the recommended AP information to the associated AP through the network device, the associated AP can forward the recommended AP information to the associated STA.

[0108] Optionally, step 602 may include: determining a first recommended AP set from the first one or more candidate APs based on the AP quality information included in the probe response frame of the first one or more candidate APs regarding the first STA; generating first recommended AP information based on the AP basic information and AP quality information of the first recommended AP set, wherein the AP basic information includes identification information and channel information of the AP, similar to the method described for associating APs in method 300 above.

[0109] Optionally, the first recommended AP information may also be related to neighbor APs operating on the same channel as the first associated AP. For example, the first associated AP may obtain (e.g., from the associated first STA (e.g., by receiving information about neighbor APs sent by the STA), or the first associated AP may obtain in other ways) relevant information (e.g., basic AP information, AP quality information, etc.) about neighbor APs operating on the same channel as the first associated AP, as described above with respect to method 300. For example, the associated AP provides the obtained information about the neighbor APs to the network device.

[0110] Optionally, the network device is a device in the wireless local area network that is different from the first associated AP and the first STA, a device that is different from all APs and the first STA, or a device outside the wireless local area network. For example, taking the WLAN in FIG1 as an example, the network device integrated with the RMU can be a device in the WLAN other than the STA 101 and the AP 102A associated with the STA 101, such as any one of the APs 102B-102F, the first network device 103, or the second network device 104, or any one of the first network device 103 and the second network device 104. The second network device 104 can be a device in the WLAN or a device outside the WLAN.

[0111] Optionally, method 600 may further include: obtaining, by the network device, probe response frames from one or more second candidate APs regarding the second STA, wherein the network device is communicatively connected to a second associated AP associated with the second STA, each candidate AP being an AP capable of receiving probe request frames from the second STA on its operating channel; generating, by the network device, second recommended AP information that can be used for roaming handover of the second STA based on the probe response frames from the one or more second candidate APs regarding the second STA; and transmitting, by the network device, the second recommended AP information to the second associated AP. Similarly, compared to conventional probe response frames, the probe response frames from the one or more second candidate APs regarding the second STA may include additional information, including but not limited to basic STA information of the second STA (e.g., MAC address of the STA, associated AP of the STA, etc.), AP quality information of the candidate APs, etc. For example, the network device may receive probe response frames from one or more candidate APs regarding STA 101B, and based on these probe response frames (e.g., analyzing information included in the probe response frames, etc.), generate corresponding recommended AP information for roaming handover of STA 101B, and transmit the corresponding recommended AP information to associated AP 102B of STA 101B. Similarly, the network device may receive a probe response frame of a candidate AP for each STA 101 in the WLAN and generate corresponding recommended AP information for each STA 101 based on the probe response frame.

[0112] In method 600, the network device integrated with the RMU can obtain the probe response frame of the candidate AP of each STA and generate recommended AP information for each STA based on the probe response frame. Therefore, the network device can achieve global management of the switchable APs of all STAs in the WLAN and send recommended AP information related to the STA corresponding to the associated AP to each associated AP.

[0113] Figure 7 shows a schematic diagram of the structure of an exemplary terminal STA 700 in a wireless local area network according to an embodiment of the present disclosure. As shown in Figure 7, STA 700 includes a transmitting module 701 and a receiving module 702. Each module of STA 700 can be implemented using software, hardware (e.g., integrated circuits, FPGAs, etc.), or a combination of software and hardware.

[0114] The sending module 701 is configured to send a first type of probe request frame on each scanning channel during an idle period when the STA does not need to transmit data on the working channel and the associated access point AP associated with the STA, wherein the first type of probe request frame includes identification information of the associated AP and the STA, wherein after the STA sends the first type of probe request frame on a scanning channel, it immediately switches to the working channel, or immediately switches to another scanning channel to send the first type of probe request frame.

[0115] The receiving module 702 is configured to receive recommended AP information that can be used for roaming handover of the STA from the associated AP, where the recommended AP information is related to one or more candidate APs that can receive the first type of probe request frame on each scanning channel.

[0116] Optionally, the recommended AP information may also be related to neighboring APs operating on the same channel as the associated AP.

[0117] Optionally, the recommended AP information is generated based on the probe response frames of the STA from the one or more candidate APs. Optionally, the recommended AP information can also be generated based on relevant information of neighbor APs operating on the same channel as the associated AP, as described above with respect to method 200.

[0118] Optionally, the STA 700 may further include a determination module, which may be configured to determine an AP to which the STA is to switch based on the recommended AP information in response to receiving an indication of AP switching from an associated AP.

[0119] Optionally, the receiving module 702 of STA 700 can receive AP quality information of the associated AP from the associated AP, and the determination module of STA 700 can be configured to: determine whether to perform AP switching based on the AP quality information of the associated AP and the recommended AP set; if the STA determines to perform AP switching, determine the AP to which the STA is to switch based on the recommended AP information.

[0120] Optionally, the receiving module 702 of the STA 700 may receive AP signal strengths of a recommended AP set or one or more candidate APs from an associated AP, and the determining module of the STA 700 may be configured to determine the location of the STA in the wireless local area network based on the acquired AP signal strengths.

[0121] Optionally, the sending module 701 of STA 700 can be configured to send a second type of probe request frame on an available channel before the STA first associates to an AP in a wireless local area network, and the receiving module 702 of STA 700 can be configured to wait for receiving a probe response frame on an available channel after sending the second type of probe request frame.

[0122] In addition, STA 700 may further include corresponding modules corresponding to one or more method steps implemented by STA in various embodiments of the present disclosure, which will not be described in detail.

[0123] Figure 8 shows a schematic diagram of the structure of an exemplary access point AP 800 in a wireless local area network according to an embodiment of the present disclosure. AP 800 is a first associated AP associated with a first terminal STA. As shown in Figure 8, AP 800 includes a receiving module 801, a generating module 802, and a transmitting module 803. Each module of AP 800 can be implemented using software, hardware (e.g., an integrated circuit, an FPGA, etc.), or a combination of software and hardware. AP 800 is integrated with an RMU to obtain probe response frames from candidate APs for each STA and generate recommended AP information for each STA based on the probe response frames. Therefore, AP 800 can achieve global management of switchable APs for all STAs in the WLAN.

[0124] The receiving module 801 is configured to receive a probe response frame regarding the first STA from one or more first candidate APs, each candidate AP being an AP capable of receiving a probe request frame from the first STA on its operating channel.

[0125] The generating module 802 is configured to generate first recommended AP information for roaming handover of the first STA based on a probe response frame regarding the first STA from one or more first candidate APs.

[0126] The sending module 803 is configured to send first recommended AP information to the first STA.

[0127] Optionally, the receiving module 801 of the AP 800 may be further configured to receive, from the associated first STA, information related to a neighboring AP operating on the same channel as the first associated AP.

[0128] Optionally, AP 800 may also include a determination module, which is configured to determine a first recommended AP set from the first one or more candidate APs based on AP quality information included in the detection response frame of the first STA of the first one or more candidate APs, and the generation module 802 is configured to generate first recommended AP information based on AP basic information and AP quality information of the first recommended AP set, wherein the AP basic information includes identification information and channel information of the AP.

[0129] Optionally, the determination module of AP 800 can also be configured to determine whether to cause the STA to perform AP switching based on the AP quality information of the first associated AP and the first recommended AP set, and the sending module 803 of AP 800 is configured to send an indication of AP switching to the STA in response to determining that the STA is to perform AP switching.

[0130] Optionally, the AP 800 may further include a sharing module, which is configured to share (for example, transmit to the APs in the recommended AP set via a wired or wireless manner, or the associated AP may store the handshake message in a storage device and provide an access address to the APs in the recommended AP set, etc.) a handshake message regarding the authentication process between the associated AP and the STA in response to determining that the STA is to perform AP switching or receiving an indication from the STA that the STA is to perform AP switching.

[0131] Optionally, the receiving module 801 is configured to receive a probe response frame regarding the second STA from a second one or more candidate APs, each candidate AP being an AP capable of receiving a probe request frame from the second STA on its working channel; the generating module 802 is configured to generate second recommended AP information for roaming switching of the second STA based on the probe response frame regarding the second STA from the second one or more candidate APs; and the sending module 803 is configured to send the second recommended AP information to a second associated AP associated with the second STA.

[0132] In addition, the AP 800 may further include corresponding modules corresponding to the steps of one or more methods (eg, method 300 , etc.) implemented by the associated AP in various embodiments of the present disclosure, which will not be described in detail.

[0133] Figure 9 shows a schematic diagram of the structure of another exemplary access point, AP 900, in a wireless local area network according to an embodiment of the present disclosure. AP 900 is an associated AP associated with a terminal STA. As shown in Figure 9, AP 900 includes a receiving module 901 and a transmitting module 902. Each module of AP 900 can be implemented using software, hardware (e.g., integrated circuits, FPGAs, etc.), or a combination of software and hardware. The RMU can be integrated into a network device other than the associated AP using hardware, software, or a combination thereof.

[0134] The receiving module 901 is configured to receive recommended AP information for STA roaming handover from a network device, where the recommended AP information is related to one or more candidate APs capable of receiving a first type of probe request frame from the STA on its working channel.

[0135] The sending module 902 is configured to send recommended AP information to the STA.

[0136] Optionally, the receiving module 901 of the AP 900 may be further configured to receive, from the associated STA, information related to a neighboring AP operating on the same channel as the associated AP.

[0137] Optionally, the recommended AP information is related to a recommended AP set determined from one or more candidate APs based on AP quality information included in a probe response frame of the one or more candidate APs regarding the STA, and the recommended AP information includes AP basic information and AP quality information of the recommended AP set, and the AP basic information includes identification information and channel information of the AP, as described above with respect to methods 200 and 300.

[0138] Optionally, the AP 900 may further include a determination module, which is configured to determine whether the STA is to perform AP switching based on AP quality information of the associated AP and the recommended AP set, and the sending module 902 of the AP 900 is configured to send an indication of AP switching to the STA in response to determining that the STA is to perform AP switching.

[0139] Optionally, the AP 900 may further include a sharing module, which is configured to share (for example, transmit to an AP in the recommended AP set via a wired or wireless manner, or the associated AP may store the handshake message in a storage device and provide an access address to the AP in the recommended AP set, etc.) a handshake message regarding the authentication process between the associated AP and the STA in response to determining that the STA is to perform AP switching or receiving an indication from the STA that the STA is to perform AP switching.

[0140] In addition, the AP 900 may further include corresponding modules corresponding to the steps of one or more methods (eg, method 400 , etc.) implemented by the associated AP in various embodiments of the present disclosure, which will not be described in detail.

[0141] Figure 10 shows a schematic diagram of the structure of another exemplary access point AP 1000 in a wireless local area network according to an embodiment of the present disclosure. As shown in Figure 10, first AP 1000 includes a receiving module 1001, a determining module 1002, and a sending module 1003. Each module of first AP 1000 can be implemented using software, hardware (e.g., integrated circuits, FPGAs, etc.), or a combination of software and hardware. The RMU can be integrated into the associated AP or into a network device different from the associated AP using hardware, software, or a combination thereof. First AP 1000 is one of the candidate APs for the STA.

[0142] The receiving module 1001 is configured to receive a probe request frame from a terminal STA on its working channel.

[0143] The determination module 1002 is configured to determine the type of the probe request frame.

[0144] The sending module 1003 is configured to send a probe response frame for the probe request frame to the associated AP associated with the STA or a network device that is communicatively connected to the first AP and the associated AP if the type of the probe request frame is the first type. The probe response frame is used to generate recommended AP information that can be used for roaming switching of the STA. The recommended AP information is also related to at least one other AP, wherein the at least one other AP is an AP that can receive the probe request frame from the STA on its working channel.

[0145] Optionally, the determination module 1002 can be configured to determine the associated AP based on the identification information of the associated AP included in the probe request frame from the STA before the first AP sends the probe response frame, so as to send a probe response frame to the associated AP or a network device that is communicatively connected to the associated AP.

[0146] Optionally, the sending module 1003 may be configured to send a probe response frame in response to the probe request frame to the STA if the type of the probe request frame is the second type.

[0147] In addition, the first AP 1000 may further include corresponding modules corresponding to the steps of one or more methods (eg, method 500 , etc.) implemented by the first AP in various embodiments of the present disclosure, which will not be described in detail.

[0148] Figure 11 shows a schematic diagram of the structure of an exemplary network device 1100 according to an embodiment of the present disclosure. As shown in Figure 11, network device 1100 includes an acquisition module 1101, a generation module 1102, and a transmission module 1103. Each module of network device 1100 can be implemented using software, hardware (e.g., integrated circuits, FPGAs, etc.), or a combination of software and hardware. The RMU can be integrated into the network device using hardware, software, or a combination thereof.

[0149] The acquisition module 1101 is configured to acquire a first probe response frame of one or more candidate APs regarding a first STA, wherein the network device is communicatively connected to a first associated AP associated with the first STA, and each candidate AP is an AP capable of receiving a probe request frame from the first STA on its working channel.

[0150] The generating module 1102 is configured to generate first recommended AP information that can be used for roaming handover of the first STA based on a probe response frame of the first one or more candidate APs with respect to the first STA.

[0151] The sending module 1103 is configured to send the first recommended AP information to the first associated AP.

[0152] Optionally, the network device 1100 may also include a determination module, which is configured to determine a first recommended AP set from the first one or more candidate APs based on the AP quality information included in the detection response frame of the first STA of the first one or more candidate APs, and the generation module 1102 of the network device 1100 may be configured to generate first recommended AP information based on the AP basic information and AP quality information of the first recommended AP set, wherein the AP basic information includes identification information and channel information of the AP.

[0153] Optionally, the acquisition module 1101 may be configured to acquire, from a first associated AP associated with the first STA, relevant information of a neighbor AP operating on the same channel as the first associated AP.

[0154] Optionally, the network device is one of a device in the wireless local area network that is different from the first associated AP and the first STA, a device that is different from all APs and the first STA, or a device outside the wireless local area network.

[0155] Optionally, the acquisition module 1101 can be configured to acquire a probe response frame of a second one or more candidate APs regarding the second STA, wherein the network device is communicatively connected to a second associated AP associated with the second STA, and each candidate AP is an AP capable of receiving a probe request frame from the second STA on its working channel. The generation module 1102 can be configured to generate second recommended AP information that can be used for roaming switching of the second STA based on the probe response frame of the second one or more candidate APs regarding the second STA, and the sending module 1103 can be configured to send the second recommended AP information to the second associated AP.

[0156] In addition, the network device 1100 may further include corresponding modules corresponding to the steps of one or more methods (eg, method 600, etc.) implemented by the network device with integrated RMU in various embodiments of the present disclosure, which will not be described in detail.

[0157] FIG12 shows a block diagram of an exemplary terminal STA 1200 according to an embodiment of the present disclosure. As shown in FIG12 , STA 1200 includes a communication unit 1201 and a processing unit 1202 operably coupled to the communication unit 1201. For example, the communication unit 1201 includes a radio communication component for implementing wireless communication, such as a wireless transceiver. The processing unit 1202 can be a general-purpose central processing unit, other types of processors, or other types of integrated circuits programmed in any manner known in the art (e.g., a structured / platform ASIC, a field programmable gate array (FPGA), a system on chip (SoC), or other semi-custom IC, etc.), etc., for implementing the processing actions implemented by the STA in each embodiment of the present disclosure. The communication unit 1201 and the processing unit 1202 are configured to execute the method steps implemented by the STA in each embodiment of the present disclosure (e.g., one or more steps in the above-described method 200, etc.).

[0158] Figure 13 shows a block diagram of an exemplary access point (AP) 1300 according to an embodiment of the present disclosure. AP 1300 is an associated AP associated with a terminal (STA). As shown in Figure 13, AP 1300 includes a communication unit 1301 and a processing unit 1302 operatively coupled to communication unit 1301. For example, communication unit 1301 includes radio communication components, such as a wireless transceiver, for implementing wireless communication. Optionally, communication unit 1301 may also include wired communication components, such as a bus transceiver, for implementing wired communication. Processing unit 1302 may be a general-purpose central processing unit (CPU), other types of processors, or other types of integrated circuits programmed in any manner known in the art (e.g., a structured / platform ASIC, FPGA, SoC, or other semi-custom IC), etc., to implement the processing actions performed by the associated AP in various embodiments of the present disclosure. Communication unit 1301 and processing unit 1302 are configured to execute the method steps performed by the associated AP in various embodiments of the present disclosure (e.g., one or more steps in methods 300 or 400 described above).

[0159] FIG14 shows a block diagram of another exemplary access point, AP 1400, according to an embodiment of the present disclosure. As shown in FIG14 , AP 1400 includes a communication unit 1401 and a processing unit 1402 operatively coupled to communication unit 1401. For example, communication unit 1401 includes radio communication components, such as a wireless transceiver, for implementing wireless communication. Optionally, communication unit 1401 may also include wired communication components, such as a bus transceiver, for implementing wired communication. Processing unit 1402 may be a general-purpose central processing unit (CPU), other types of processors, or other types of integrated circuits programmed in any manner known in the art (e.g., a structured / platform ASIC, FPGA, SoC, or other semi-custom IC), etc., to implement the processing actions implemented by the first AP in various embodiments of the present disclosure. Communication unit 1401 and processing unit 1402 are configured to execute the method steps implemented by the associated AP in various embodiments of the present disclosure (e.g., one or more steps in method 500 described above).

[0160] Figure 15 shows a block diagram of an exemplary network device 1500 in a wireless local area network according to an embodiment of the present disclosure. As shown in Figure 15, network device 1500 includes a communication unit 1501 and a processing unit 1502 operatively coupled to communication unit 1501. For example, communication unit 1501 includes radio communication components (e.g., a wireless transceiver) for implementing wireless communication and / or wired communication components (e.g., a bus transceiver) for implementing wired communication. Processing unit 1502 can be a general-purpose central processing unit (CPU), other types of processors, or other types of integrated circuits programmed in any manner known in the art (e.g., a structured / platform ASIC, FPGA, SoC, or other semi-custom IC), etc., to implement the processing actions performed by the first AP in various embodiments of the present disclosure. Communication unit 1501 and processing unit 1502 are configured to execute the method steps performed by the associated AP in various embodiments of the present disclosure (e.g., one or more steps in method 600 described above).

[0161] An embodiment of the present disclosure further provides a wireless local area network roaming handover system (e.g., system 100 in FIG. 1 ), the system including multiple APs and a first terminal STA, the multiple APs including a first associated AP associated with the first STA, and first one or more candidate APs included in the multiple APs, each of the first one or more candidate APs being an AP capable of receiving a probe request frame from the first STA on its operating channel, the first STA being configured to implement, for example, the aforementioned method 200, each of the first one or more candidate APs being configured to implement, for example, the aforementioned method 500, the first associated AP being configured to implement, for example, the aforementioned method 300, and a network device being configured to implement, for example, the aforementioned method 300. For example, the RMU may be integrated into the first associated AP in a hardware manner, a software manner, or a combination thereof.

[0162] Optionally, the system includes a second STA, a second one or more candidate APs are included in the multiple APs, each of the second one or more candidate APs is an AP capable of receiving a probe request frame from the second STA on its working channel, and the second STA is used to implement, for example, the above-mentioned method 200.

[0163] Embodiments of the present disclosure also provide a wireless local area network roaming handover system (e.g., system 100 in FIG. 1 ), the system including multiple APs, a first terminal STA, and a network device, the multiple APs including a first associated AP associated with the first STA, and one or more first candidate APs included in the multiple APs, each of the one or more first candidate APs being an AP capable of receiving a probe request frame from the first STA on its operating channel, the first STA being configured to implement, for example, the aforementioned method 200, each of the one or more candidate APs being configured to implement, for example, the aforementioned method 500, the first associated AP being configured to implement, for example, the aforementioned method 400, and the network device being configured to implement, for example, the aforementioned method 600. For example, the RMU may be integrated into the network device in a hardware manner, a software manner, or a combination thereof.

[0164] Optionally, the system includes a second STA, a second one or more candidate APs are included in the multiple APs, each of the second one or more candidate APs is an AP capable of receiving a probe request frame from the second STA on its working channel, and the second STA is used to implement, for example, the above-mentioned method 200.

[0165] An embodiment of the present disclosure further provides a computer-readable storage medium having computer-executable instructions stored thereon. When the computer-executable instructions are executed by a processor, the wireless local area network roaming switching method described above (for example, one or more method steps in methods 200 to 600, etc.) is implemented.

[0166] An embodiment of the present disclosure further provides a computer program product, which includes computer-executable instructions. When the computer-executable instructions are executed by a processor, the wireless local area network roaming switching method described above (for example, one or more method steps in methods 200 to 600, etc.) is implemented.

[0167] As described above, the solution disclosed herein can be based on mainstream WLAN features such as those defined in the IEEE 802.11 series of standards, reducing the time required for roaming, thereby meeting industrial latency / jitter requirements. Compared with existing technologies, the solution disclosed herein has the following advantages:

[0168] a) The solution is easy to implement. For example, RMU can be an application running on existing edge hardware (e.g., Siemens' Scalance LPE);

[0169] b) Easily integrate with WiFi roaming standards such as IEEE 802.11k / v / r to improve performance;

[0170] c) It can significantly reduce roaming time and meet the needs of time-sensitive applications;

[0171] d) Applicable to multiple generations of WLAN standards, including IEEE 802.11a / b / g / n / ac / ax.

[0172] Nouns and pronouns referring to persons in this patent application are not limited to a specific gender.

[0173] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A wireless local area network roaming switching method, applicable to a terminal (STA), characterized in that: The method comprises: During an idle period when the STA does not need to perform data transmission on a working channel and an associated access point (AP) associated with the STA, sending a first type of probe request frame on each scanning channel, wherein the first type of probe request frame includes identification information of the associated AP and the STA, wherein after sending the first type of probe request frame on one scanning channel, switching to the working channel is performed immediately, or switching to another scanning channel to send the first type of probe request frame is performed immediately; and Recommended AP information that can be used for roaming handover of the STA is received from the associated AP, where the recommended AP information is related to one or more candidate APs that can receive a first type of probe request frame on each scanning channel.

2. The method according to claim 1, characterized in that The recommended AP information is generated based on a probe response frame regarding the STA from the one or more candidate APs.

3. The method according to claim 1 or 2, characterized in that: The recommended AP information is related to a recommended AP set determined from the one or more candidate APs based on the AP quality information included in the detection response frame of the one or more candidate APs regarding the STA, and the recommended AP information includes AP basic information and AP quality information of the recommended AP set, and the AP basic information includes AP identification information and channel information.

4. The method according to claim 3, characterized in that The method comprises: In response to receiving an indication of performing AP switching from the associated AP, an AP to which the STA is to switch is determined based on the recommended AP information.

5. The method according to claim 3, characterized in that: The method comprises: Acquire AP quality information of the associated AP; Determining whether to perform AP switching based on the associated AP and the AP quality information of the recommended AP set; If it is determined that AP switching is to be performed, then the AP to which the STA is to switch is determined based on the recommended AP information.

6. The method according to claim 3, characterized in that The AP quality information includes at least one of AP load status, AP signal strength, AP signal-to-interference ratio, and information indicating whether the AP rejects or allows a new STA.

7. The method according to claim 6, characterized in that The method comprises: Acquire AP signal strengths of the recommended AP set or the one or more candidate APs; Based on the acquired AP signal strength, the position of the STA in the wireless local area network is determined.

8. The method according to claim 1, characterized in that: The method comprises: Before the STA associates with an AP in a wireless local area network for the first time, a second type of probe is sent on an available channel. Test request frame; After sending the second type of probe request frame, the STA waits for a probe response frame on the available channel.

9. A wireless local area network roaming switching method, applicable to an access point (AP), characterized in that: The method comprises: A first associated AP associated with a first terminal (STA) receives a probe response frame regarding the first STA from first one or more candidate APs, each candidate AP being an AP capable of receiving a probe request frame from the first STA on its operating channel; The first associated AP generates first recommended AP information for roaming handover of the first STA based on the probe response frame about the first STA from the first one or more candidate APs; and The first associated AP sends the first recommended AP information to the first STA.

10. The method according to claim 9, characterized in that Generating, by the first associated AP, first recommended AP information based on a probe response frame about the first STA from the first one or more candidate APs includes: determining a first recommended AP set from the first one or more candidate APs based on AP quality information included in a probe response frame of the first one or more candidate APs with respect to the first STA; The first recommended AP information is generated based on AP basic information and AP quality information of the first recommended AP set, wherein the AP basic information includes identification information and channel information of the AP.

11. The method according to claim 10, characterized in that The method comprises: Determine whether to enable the first STA to perform AP switching based on the AP quality information of the first associated AP and the first recommended AP set; In response to determining that the first STA is to perform AP switching, an instruction for performing AP switching is sent to the first STA.

12. The method according to claim 11, characterized in that The method comprises: In response to determining that the first STA is to perform AP switching or receiving an indication from the first STA that the first STA is to perform AP switching, a handshake message regarding an authentication process between the first associated AP and the first STA is shared with APs in the first recommended AP set.

13. The method according to claim 9, characterized in that The method comprises: The first associated AP receives a probe response frame regarding the second STA from one or more second candidate APs, each candidate AP being an AP capable of receiving a probe request frame from the second STA on its operating channel; generating, by the first associated AP, second recommended AP information for roaming handover of the second STA based on a probe response frame about the second STA from the second one or more candidate APs; and The first associated AP sends the second recommended AP information to a second associated AP associated with the second STA.

14. A wireless local area network roaming switching method, applicable to an access point (AP), characterized in that: The method comprises: An associated AP associated with a terminal (STA) receives recommended AP information for roaming handover of the STA from a network device, wherein the recommended AP information is related to one or more candidate APs capable of receiving a first type of probe request frame from the STA on its working channel; and The recommended AP information is sent from the associated AP to the STA.

15. The method according to claim 14, characterized in that The recommended AP information is generated based on a probe response frame regarding the STA from the one or more candidate APs.

16. The method according to claim 14, characterized in that The recommended AP information is related to a recommended AP set determined from the one or more candidate APs based on the AP quality information included in the detection response frame of the one or more candidate APs regarding the STA, and the recommended AP information includes AP basic information and AP quality information of the recommended AP set, and the AP basic information includes AP identification information and channel information.

17. The method according to claim 16, characterized in that The method comprises: Determining whether to enable the STA to perform AP switching based on the associated AP and the AP quality information of the recommended AP set; In response to determining that the STA is to perform AP switching, an indication for performing AP switching is sent to the STA.

18. The method according to claim 17, characterized in that The method comprises: In response to determining that the STA is to perform AP switching or receiving an indication from the STA that the STA is to perform AP switching, a handshake message regarding an authentication process between the associated AP and the STA is shared with APs in the recommended AP set.

19. The method according to claim 14, characterized in that The network device is one of a device in the wireless local area network that is different from the associated AP and the STA, a device that is different from all APs and the STA, or a device outside the wireless local area network.

20. A wireless local area network roaming switching method, applicable to an access point (AP), characterized in that: The method comprises: The first AP receives a probe request frame from a terminal (STA) on its working channel; The first AP determines a type of the probe request frame; and If the type of the probe request frame is the first type, the first AP sends a probe response frame for the probe request frame to an associated AP associated with the STA or a network device that is communicatively connected to the first AP and the associated AP, and the probe response frame is used to generate recommended AP information that can be used for roaming switching of the STA, and the recommended AP information is also related to at least one other AP, wherein the at least one other AP is an AP that can receive the probe request frame from the STA on its working channel.

21. The method according to claim 20, characterized in that The method comprises: Before the first AP sends the probe response frame, the associated AP is determined according to the identification information of the associated AP included in the probe request frame.

22. The method according to claim 20, characterized in that The method comprises: If the type of the probe request frame is the second type, the first AP sends a probe response frame to the STA in response to the probe request frame.

23. A wireless local area network roaming switching method, applicable to a network device, characterized in that: The method comprises: Acquiring, by a network device, a probe response frame of one or more first candidate APs with respect to a first STA, wherein the network device is communicatively connected to a first associated AP associated with the first STA, and each candidate AP is an AP capable of receiving a probe request frame from the first STA on its working channel; Generating, by the network device, first recommended AP information that can be used for roaming handover of the first STA based on the probe response frames of the first one or more candidate APs with respect to the first STA; and The first recommended AP information is sent by the network device to the first associated AP.

24. The method according to claim 23, characterized in that Generating, by the network device, the first recommended AP information based on the probe response frame of the first one or more candidate APs about the first STA includes: determining a first recommended AP set from the first one or more candidate APs based on AP quality information included in a probe response frame of the first one or more candidate APs with respect to the first STA; The first recommended AP information is generated based on AP basic information and AP quality information of the first recommended AP set, wherein the AP basic information includes identification information and channel information of the AP.

25. The method according to claim 23, characterized in that The network device is one of a device in the wireless local area network that is different from the first associated AP and the first STA, a device that is different from all APs and the first STA, or a device outside the wireless local area network.

26. The method according to claim 23, characterized in that The method comprises: The network device obtains a probe response frame of the second STA from one or more second candidate APs, wherein: The network device is communicatively connected to a second associated AP associated with the second STA, each candidate AP being an AP capable of receiving a probe request frame from the second STA on its operating channel; Generating, by the network device, second recommended AP information that can be used for roaming handover of the second STA based on the probe response frames of the second one or more candidate APs regarding the second STA; and The network device sends the second recommended AP information to the second associated AP.

27. A terminal (STA) in a wireless local area network, characterized in that: The STA includes: a sending module, configured to send a first type of probe request frame on each scanning channel during an idle period when the STA does not need to perform data transmission on a working channel and an associated access point (AP) associated with the STA, wherein the first type of probe request frame includes identification information of the associated AP and the STA, wherein after sending the first type of probe request frame on one scanning channel, the working channel is immediately switched to, or the first type of probe request frame is immediately switched to another scanning channel; and The receiving module is configured to receive recommended AP information that can be used for roaming handover of the STA from the associated AP, wherein the recommended AP information is related to one or more candidate APs that can receive the first type of probe request frame on each scanning channel.

28. An access point (AP) in a wireless local area network, characterized in that: The AP is a first associated AP associated with a first terminal (STA), and the first associated AP includes: a receiving module configured to receive a probe response frame about the first STA from one or more first candidate APs, each candidate AP being an AP capable of receiving a probe request frame from the first STA on its working channel; a generating module configured to generate first recommended AP information for roaming switching of the first STA based on a probe response frame about the first STA from the first one or more candidate APs; and A sending module is configured to send the first recommended AP information to the first STA.

29. The AP according to claim 27, characterized in that: The receiving module is configured to receive a probe response frame about a second STA from one or more second candidate APs, each candidate AP being an AP capable of receiving a probe request frame from the second STA on its working channel; The generating module is configured to generate second recommended AP information for roaming switching of the second STA based on the probe response frame about the second STA from the second one or more candidate APs; as well as The sending module is configured to send the second recommended AP information to a second associated AP associated with the second STA.

30. An access point (AP) in a wireless local area network, characterized in that: The AP is associated with a terminal (STA), and the AP includes: a receiving module configured to receive, from a network device, recommended AP information for roaming handover of the STA, the recommended AP information being related to one or more candidate APs capable of receiving a first type of probe request frame from the STA on its working channel; and The sending module is configured to send the recommended AP information to the STA.

31. A first access point (AP) in a wireless local area network, characterized in that: The first AP includes: A receiving module, configured to receive a probe request frame from a terminal (STA) on its working channel; a determination module configured to determine a type of the probe request frame; and A sending module is configured to send a probe response frame for the probe request frame to an associated AP associated with the STA or a network device that is communicatively connected to the first AP and the associated AP if the type of the probe request frame is a first type, wherein the probe response frame is used to generate recommended AP information that can be used for roaming switching of the STA, and the recommended AP information is also related to at least one other AP, wherein the at least one other AP is an AP that can receive the probe request frame from the STA on its working channel.

32. A network device, characterized in that: The network equipment includes: an acquisition module configured to acquire a probe response frame of a first one or more candidate APs about a first STA, wherein the network device is communicatively connected to a first associated AP associated with the first STA, and each candidate AP is an AP capable of receiving a probe request frame from the first STA on its working channel; a generating module configured to generate first recommended AP information that can be used for roaming switching of the first STA based on the probe response frames of the first one or more candidate APs with respect to the first STA; and A sending module is configured to send the first recommended AP information to the first associated AP.

33. The network device according to claim 32, characterized in that: The acquisition module is configured to acquire a probe response frame of a second one or more candidate APs with respect to a second STA, wherein the network device is communicatively connected to a second associated AP associated with the second STA, and each candidate AP is an AP capable of receiving a probe request frame from the second STA on its working channel; The generating module is configured to generate second recommended AP information that can be used for roaming switching of the second STA based on the probe response frames of the second one or more candidate APs about the second STA; and The sending module is configured to send the second recommended AP information to the second associated AP.

34. A terminal (STA) in a wireless local area network, characterized in that: The STA includes: a communication unit; and a processing unit operatively coupled to the communication unit; The communication unit and the processing unit are configured to execute the wireless local area network roaming switching method according to any one of claims 1 to 8.

35. An access point (AP) in a wireless local area network, characterized in that: The AP is a first associated AP associated with a first terminal (STA), and the first associated AP includes: a communication unit; and a processing unit operatively coupled to the communication unit; The communication unit and the processing unit are configured to execute the wireless local area network roaming switching method according to any one of claims 9 to 19.

36. A first access point (AP) in a wireless local area network, characterized in that: The first AP includes: a communication unit; and a processing unit operatively coupled to the communication unit; The communication unit and the processing unit are configured to execute the wireless local area network roaming switching method according to any one of claims 20 to 22.

37. A network device, characterized in that: The network equipment includes: a communication unit; and a processing unit operatively coupled to the communication unit; The communication unit and the processing unit are configured to execute the wireless local area network roaming switching method according to any one of claims 23 to 26.

38. A wireless local area network roaming switching system, characterized in that: The system includes a plurality of access points (APs) and a first terminal (STA), the plurality of APs including a first associated AP associated with the first STA, and first one or more candidate APs included in the plurality of APs, each of the first one or more candidate APs being an AP capable of receiving a probe request frame from the first STA on its operating channel; The first STA is used to perform the wireless local area network roaming switching method according to any one of claims 1 to 8, Each of the first one or more candidate APs is used to perform the wireless local area network roaming switching method according to any one of claims 20 to 22, The first associated AP is used to execute the wireless local area network roaming switching method according to any one of claims 9 to 13.

39. The system according to claim 38, characterized in that The system includes a second STA, second one or more candidate APs are included in the plurality of APs, each of the second one or more candidate APs is an AP capable of receiving a probe request frame from the second STA on its operating channel, and The second STA is used to execute the wireless local area network roaming handover method according to any one of claims 1 to 8.

40. A wireless local area network roaming switching system, characterized in that: The system includes a plurality of access points (APs), a first terminal (STA), and a network device, the plurality of APs including a first associated AP associated with a first STA, and first one or more candidate APs included in the plurality of APs, each of the first one or more candidate APs being an AP capable of receiving a probe request frame from the first STA on its working channel, The first STA is used to perform the wireless local area network roaming switching method according to any one of claims 1 to 8, Each of the first one or more candidate APs is used to perform the wireless local area network roaming switching method according to any one of claims 20 to 22, The associated AP is used to perform the wireless local area network roaming switching method according to any one of claims 13 to 19, The network device is used to execute the wireless local area network roaming switching method according to any one of claims 23 to 26.

41. The system according to claim 40, characterized in that The system includes a second STA, second one or more candidate APs are included in the plurality of APs, each of the second one or more candidate APs is an AP capable of receiving a probe request frame from the second STA on its operating channel, and The second STA is used to execute the wireless local area network roaming handover method according to any one of claims 1 to 8.

42. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer-executable instructions, and when the computer-executable instructions are executed by a processor, the wireless local area network roaming switching method according to any one of claims 1 to 26 is implemented.

43. A computer program product, characterized in that The computer program product comprises computer executable instructions, and when the computer executable instructions are executed by a processor, the wireless local area network roaming switching method according to any one of claims 1 to 26 is implemented.

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