Link switching method and device, equipment and medium

Abstract

The invention discloses a link switching method and device, equipment and a medium, and relates to the field of communication. The method comprises the following steps: sending power control information in a process of switching a first source link to a first target link; wherein the power control information is used for controlling the transmitting power of the candidate AP MLD or the target AP MLD, the first source link is at least one link corresponding to the STA MLD and the source AP MLD, the first target link is at least one link corresponding to the STA MLD and the target AP MLD, and the target AP MLD is one AP MLD in the candidate AP MLD. The method provided by the invention is helpful for improving the reliability of the first target link.

Description

Link switching method, device, equipment and medium Technical Field

[0001] The present application relates to the field of communications, and in particular to a link switching method, apparatus, device, and medium. Background Art

[0002] When a station (STA) roams, it is usually necessary to perform link switching. However, the link switching method in the related art cannot guarantee the reliability of the newly established link, thereby having a negative impact on the communication quality of the communication system.

[0003] Summary of the Invention

[0004] The present invention provides a link switching method, apparatus, device, and medium. The technical solution is as follows:

[0005] According to one aspect of the present application, a link switching method is provided. The method is performed by a station (STA) multi-link device (MLD), and the method includes:

[0006] During the switching of the first source link to the first target link, sending power control information;

[0007] The power control information is used to control the transmission power of the candidate AP MLD or the target AP MLD, the first source link is at least one link corresponding to the STA MLD and the source AP MLD, the first target link is at least one link corresponding to the STA MLD and the target AP MLD, and the target AP MLD is one of the candidate AP MLDs.

[0008] According to one aspect of the present application, a link switching method is provided. The method is performed by a target access point (AP) MLD, and the method includes:

[0009] receiving power control information during switching the first source link to the first target link;

[0010] The power control information is used to control the transmission power of the candidate AP MLD or the target AP MLD, the first source link is at least one link corresponding to the STA MLD and the source AP MLD, the first target link is at least one link corresponding to the STA MLD and the target AP MLD, and the target AP MLD is one of the candidate AP MLDs.

[0011] According to one aspect of the present application, a link switching method is provided. The method is performed by a source AP MLD, and the method includes:

[0012] transmitting power control information during switching the first source link to the first target link;

[0013] The power control information is used to control the transmission power of the candidate AP MLD or the target AP MLD, the first source link is at least one link corresponding to the STA MLD and the source AP MLD, the first target link is at least one link corresponding to the STA MLD and the target AP MLD, and the target AP MLD is one of the candidate AP MLDs.

[0014] According to one aspect of the present application, a link switching device is provided, the device comprising:

[0015] A first sending module, configured to send power control information during a process of switching the first source link to the first target link;

[0016] The power control information is used to control the transmission power of the candidate AP MLD or the target AP MLD, the first source link is at least one link corresponding to the device and the source AP MLD, the first target link is at least one link corresponding to the device and the target AP MLD, and the target AP MLD is one of the candidate AP MLDs.

[0017] According to one aspect of the present application, a link switching device is provided, the device comprising:

[0018] A second receiving module is configured to receive power control information during the process of switching the first source link to the first target link;

[0019] The power control information is used to control the transmission power of the candidate AP MLD or the device, the first source link is at least one link corresponding to the STA MLD and the source AP MLD, the first target link is at least one link corresponding to the STA MLD and the device, and the device is one of the AP MLDs among the candidate AP MLDs.

[0020] According to one aspect of the present application, a link switching device is provided, the device comprising:

[0021] a transmission module, configured to transmit power control information during the process of switching the first source link to the first target link;

[0022] The power control information is used to control the transmission power of the candidate AP MLD or the target AP MLD, the first source link is at least one link corresponding to the STA MLD and the device, the first target link is at least one link corresponding to the STA MLD and the target AP MLD, and the target AP MLD is one of the candidate AP MLDs.

[0023] According to one aspect of the present application, a wireless device is provided, which includes: a processor; a transceiver connected to the processor; and a memory for storing executable instructions of the processor; wherein the processor is configured to load and execute the executable instructions to implement the link switching method as described in the above aspect.

[0024] According to one aspect of the present application, a computer-readable storage medium is provided, in which executable instructions are stored. The executable instructions are loaded and executed by a processor to implement the link switching method as described in the above aspect.

[0025] According to one aspect of the present application, a computer program product is provided, which includes computer instructions, the computer instructions are stored in a computer-readable storage medium, a processor of a computer device reads the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions, so that the computer device executes to implement the link switching method as described in the above aspect.

[0026] According to one aspect of the present application, a chip is provided, which includes a programmable logic circuit and / or program instructions, and when the chip is running, is used to implement the link switching method described in the above aspect.

[0027] According to one aspect of the present application, a computer program is provided, which includes computer instructions. A processor of a computer device executes the computer instructions, so that the computer device executes the link switching method as described in the above aspect.

[0028] The technical solutions provided by the embodiments of the present application include at least the following beneficial effects:

[0029] The STA MLD is supported to control the transmit power of the candidate AP MLD by sending power control information during the link switching process, so that the first target link between the STA MLD and the target AP MLD has higher reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0031] FIG1 shows a schematic diagram of a roaming technology in the related art;

[0032] FIG2 is a schematic diagram showing a flow chart of a link switching method provided by some exemplary embodiments of the present application;

[0033] FIG3 shows a schematic flow chart of a link switching method provided by some exemplary embodiments of the present application;

[0034] FIG4 shows a schematic diagram of a wireless communication system provided by some exemplary embodiments of the present application;

[0035] FIG5 is a schematic diagram showing a flow chart of a link switching method provided by some exemplary embodiments of the present application;

[0036] FIG6 shows a schematic flow chart of a link switching method provided by some exemplary embodiments of the present application;

[0037] FIG7 shows a schematic flow chart of a link switching method provided by some exemplary embodiments of the present application;

[0038] FIG8 shows a schematic flow chart of a link switching method provided by some exemplary embodiments of the present application;

[0039] FIG9 is a schematic flow chart showing a link switching method provided by some exemplary embodiments of the present application;

[0040] FIG10 is a schematic diagram showing a flow chart of a link switching method provided in some exemplary embodiments of the present application;

[0041] FIG11 is a schematic diagram showing a link switching method provided by some exemplary embodiments of the present application;

[0042] FIG12 is a schematic diagram showing a flow chart of a link switching method provided in some exemplary embodiments of the present application;

[0043] FIG13 is a schematic diagram showing a format of a first frame provided by some exemplary embodiments of the present application;

[0044] FIG14 is a schematic diagram showing a format of a second frame provided by some exemplary embodiments of the present application;

[0045] FIG15 is a schematic diagram showing a flow chart of a link switching method provided by some exemplary embodiments of the present application;

[0046] FIG16 is a schematic diagram showing a format of a third frame provided by some exemplary embodiments of the present application;

[0047] FIG17 is a schematic diagram showing a format of a fourth frame provided by some exemplary embodiments of the present application;

[0048] FIG18 is a schematic diagram showing a format of a fifth frame provided by some exemplary embodiments of the present application;

[0049] FIG19 shows a schematic diagram showing the relationship between communication quality and link switching according to some exemplary embodiments of the present application;

[0050] FIG20 shows a structural block diagram of a link switching device provided by some exemplary embodiments of the present application;

[0051] FIG21 shows a structural block diagram of a link switching device provided by some exemplary embodiments of the present application;

[0052] FIG22 shows a structural block diagram of a link switching device provided by some exemplary embodiments of the present application;

[0053] FIG23 shows a schematic structural diagram of a wireless communication device provided by some exemplary embodiments of the present application. DETAILED DESCRIPTION

[0054] To make the objectives, technical solutions, and advantages of the present application more clear, the embodiments of the present application will be further described in detail below with reference to the accompanying drawings. Exemplary embodiments will be described in detail herein, with examples shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. Instead, they are merely examples of devices and methods consistent with certain aspects of the present application, as detailed in the appended claims.

[0055] The terms used in this application are for the purpose of describing specific embodiments only and are not intended to limit this application. As used in this application and the appended claims, the singular forms "a," "an," "the," and "the" are intended to include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the term "and / or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

[0056] It should be understood that although the terms first, second, third, etc. may be used in this application to describe various information, this information should not be limited to these terms. These terms are only used to distinguish information of the same type from each other. For example, without departing from the scope of this application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the word "if" as used herein can be interpreted as "at the time of" or "when" or "in response to determination". In this specification, when expressing the meaning expressed by a Boolean value, it will be expressed as '0' for 'first meaning' and '1' for 'second meaning'. Without loss of generality, those skilled in the art will understand that its representative meaning can be swapped, that is, '1' for 'first meaning' and '0' for 'second meaning'.

[0057] (1) Seamless roaming technology

[0058] In the related art, when a STA roams between multiple APs, it needs to establish a connection with a target AP in a Break-Before-Make manner, which may cause data transmission interruption during link switching.

[0059] Although the fast roaming technology in the related art can reduce the duration of data transmission interruption during link switching, it cannot completely solve the problem of data transmission interruption during link switching.

[0060] Multi-Link Operation (MLO) technology allows multi-link stations (STA Multi-Link Device, STA MLD) to transmit simultaneously using multiple links. This technology enables seamless break-before-make handover, also known as seamless roaming. Figure 1 shows the principle of seamless roaming technology.

[0061] Figure 1 shows a multi-link framework called "Single Mobility Domain (SMD) AP MLD," which includes STA MLD 110, AP MLD 120, AP MLD 130, and x. x represents the upper media access control (UMAC) sublayer of the SMD AP MLD, which is primarily responsible for authentication, association, and other operations of the SMD AP MLD. The AP MLD and UMAC sublayer within area 140 constitute the SMD AP MLD. When STA MLD 110 roams, it maintains link 150 with AP MLD 130 and establishes a new link 160 with AP MLD 120. During this period, due to the presence of x, STA MLD 110 and AP MLD 120 do not need to re-authenticate. After the STA MLD 110 successfully establishes a connection with the AP MLD 120 , the link 170 between the STA MLD 110 and the AP MLD 130 is disconnected, completing a seamless handover, thereby avoiding the problem of data transmission interruption during the link handover.

[0062] (2) Fast Basic Service Set Transition (FT)

[0063] FT is a fast roaming technology that eliminates the need for STAs to reauthenticate with the target AP during roaming. Instead, STAs recalculate the pairwise transient key (PTK) and group transient key (GTK) using the key obtained during the initial association process between the STA and the current AP. The STA then establishes a connection with the target AP using the PTK and GTK. This ensures low latency for service data flows during roaming, preventing users from experiencing data interruptions and improving the user experience.

[0064] FT technology provides two link switching modes: over-the-air switching and over-the-distribution system switching (over-the-DS).

[0065] 1. In Over-the-Air mode, the STA directly performs FT authentication with the target AP. The specific process is shown in Figure 2:

[0066] Step 201: STA associates with the current AP;

[0067] That is, a connection has been established between the STA and the current AP, and operations such as session management and data transmission can be performed between the STA and the current AP.

[0068] When a STA accesses the network for the first time through the current AP, authentication succeeds and a PTK is generated.

[0069] Step 202: The STA sends an FT Authentication Request to the target AP.

[0070] After receiving the FT authentication request from the STA, the target AP generates and installs the PTK.

[0071] Step 203: The target AP sends an FT authentication response (FT Authentication Response) to the STA;

[0072] After receiving the FT authentication response from the target AP, the STA generates and installs the PTK.

[0073] Step 204: The STA sends an FT Reassociation Request to the target AP.

[0074] After receiving the FT reassociation request from the STA, the target AP generates and installs the GTK.

[0075] Step 205: The target AP sends an FT Reassociation Response to the STA.

[0076] After receiving the FT reassociation response from the target AP, the STA generates and installs the GTK.

[0077] Step 206: The STA completes roaming from the current AP to the target AP.

[0078] The STA can perform operations such as session management and data transmission with the target AP.

[0079] 2. In Over-the-DS mode, the STA performs FT authentication with the target AP through the current AP. The specific process is shown in Figure 3:

[0080] Step 301: STA associates with the current AP;

[0081] That is, a connection has been established between the STA and the current AP, and session management and data transmission can be performed between the STA and the current AP.

[0082] When a STA accesses the network for the first time through the current AP, authentication succeeds and a PMK is generated.

[0083] Step 302: The STA sends an FT request to the current AP.

[0084] Step 303: The current AP synchronizes the FT request to the target AP;

[0085] The target AP generates and installs a PTK.

[0086] Step 304: The target AP sends an FT response (FT Response) to the current AP;

[0087] Step 305: The current AP synchronizes the FT response to the STA;

[0088] STA generates and installs the PTK.

[0089] Step 306: The STA sends an FT Reassociation Request to the target AP.

[0090] After receiving the FT reassociation request from the STA, the target AP generates and installs the GTK.

[0091] Step 307: The target AP sends an FT Reassociation Response to the STA.

[0092] After receiving the FT reassociation response from the target AP, the STA generates and installs the GTK.

[0093] Step 308: The STA completes roaming from the current AP to the target AP.

[0094] The STA can perform operations such as session management and data transmission with the target AP.

[0095] However, the above roaming technology does not consider the roaming reliability issue, that is, the new link established between the STA and the target AP is likely to have low reliability, and cannot guarantee that the new link between the STA and the target AP has high stability, low bit error rate, low packet loss rate, etc.

[0096] Based on the above problems, the present application proposes a link switching method, which helps to improve the reliability of the new link established between the STA and the target AP.

[0097] Figure 4 shows a schematic diagram of a wireless communication system provided by an exemplary embodiment of the present application. The wireless communication system includes terminal devices, terminal devices and network devices, or APs and STAs, which are not limited in this application. This application uses an example of a wireless communication system including AP 410 and non-AP STA 420 for illustration.

[0098] In some scenarios, an AP may be referred to as an AP STA, that is, in a sense, an AP is also a type of STA.

[0099] In some embodiments, STAs may include AP STAs and non-AP STAs.

[0100] Communication in a wireless communication system can be between an AP and a non-AP STA, between a non-AP STA and a non-AP STA, or between a STA and a peer STA. A peer STA refers to a device that communicates with the STA. For example, a peer STA may be an AP or a non-AP STA.

[0101] An AP acts as a bridge between wired and wireless networks, connecting wireless network clients together and then connecting the wireless network to the Ethernet. An AP can be a terminal device or network device equipped with a Wireless Fidelity (Wi-Fi) chip.

[0102] It should be understood that the role of STA in the communication system is not absolute. For example, in some scenarios, when a mobile phone is connected to a router, the mobile phone is a non-AP STA. When the mobile phone serves as a hotspot for other mobile phones, the mobile phone plays the role of AP.

[0103] APs and non-AP STAs can be devices used in the Internet of Vehicles, IoT nodes and sensors in the Internet of Things (IoT), smart cameras, smart remote controls, smart water and electricity meters in smart homes, and sensors in smart cities.

[0104] In some embodiments, a non-AP STA can support various current and future 802.11 family wireless local area network (WLAN) standards, such as 802.11be, 802.11ax, 802.11ac, 802.11n, 802.11g, 802.11b, and 802.11a. A non-AP STA can also be used in a network environment supporting a next-generation WLAN system, which is a WLAN system evolved from the 802.11ax system and can meet backward compatibility with the 802.11ax system. Next-generation Wi-Fi communication refers to any new generation of Wi-Fi communication after Wi-Fi 7 based on the IEEE 802.11be specification, such as Ultra High Reliability (UHR) communication. For example, a non-AP STA is a UHR STA.

[0105] In some embodiments, the AP may be a device that supports various current and future 802.11 family WLAN standards, such as 802.11be, 802.11ax, 802.11ac, 802.11n, 802.11g, 802.11b, and 802.11a. The AP may also be used in a network environment supporting a next-generation WLAN system, which is an evolved WLAN system from the 802.11ax system and is backward compatible with the 802.11ax system. Next-generation Wi-Fi communication refers to any new generation of Wi-Fi communication after Wi-Fi 7 based on the IEEE 802.11be specification, such as Ultra High Resolution (UHR) communication. For example, the AP is a Ultra High Resolution (UHR) AP.

[0106] In the embodiment of the present application, the non-AP STA may be a mobile phone, tablet computer, e-book reader, laptop computer, desktop computer, television, virtual reality (VR) device, augmented reality (AR) device, mixed reality (MR) device, extended reality (XR) device, baffle reality (BR) device, cinematic reality (CR) device, deceived reality (DR) device, wireless device in industrial control, set-top box, wireless device in self-driving, in-vehicle communication device, wireless device in remote medical care, wireless device in smart grid, wireless device in transportation safety, wireless device in smart city, wireless device in smart home, wireless communication chip, application specific integrated circuit (ASIC), system on chip (SoC), etc. on Chip, SoC) etc.

[0107] The wireless communication system in the embodiment of the present application can support frequency bands including but not limited to: millimeter wave frequency bands (such as 45GHz, 60GHz, etc., which belong to the frequency bands in the range of 30 to 300GHz), Sub-7GHz frequency bands (such as 2.4GHz, 5GHz, 6GHz, etc., which belong to the frequency bands in the range of 1 to 7.25GHz).

[0108] One or more links may exist between a non-AP STA and an AP.

[0109] In some embodiments, non-AP STAs and APs support multi-band communication, for example, simultaneously communicating in at least one of the 2.4 GHz, 5 GHz, 6 GHz, 45 GHz, and 60 GHz frequency bands, or simultaneously communicating on different channels in the same frequency band or different channels in different frequency bands, to improve the communication throughput and / or reliability between devices. Such devices are generally referred to as multi-band devices, or MLDs, and are sometimes also referred to as multi-band entities or multi-link entities. An MLD can be an AP device or a non-AP STA device. If the MLD is an AP device, it contains one or more APs; if the MLD is a non-AP STA device, it contains one or more non-AP STAs.

[0110] An MLD that includes one or more APs is called an AP MLD. An MLD that includes one or more non-AP STAs is called a Non-AP MLD or STA MLD.

[0111] In some embodiments, a device operating in a millimeter frequency band has a multi-link operation (MLO) capability, and in addition to a station (STA) / access point (AP) in a millimeter wave frequency band, has at least one subordinate STA / AP in a low-frequency band, and performs device association and discovery in the low-frequency band.

[0112] In some embodiments, STAs exist in the form of one or more Basic Service Sets (BSSs), which are a collection of STAs that can successfully synchronize to communicate with each other. A BSS may or may not include an AP.

[0113] In some embodiments, the AP MLD may include multiple APs, the STA MLD may include multiple STAs, multiple links may be formed between the APs in the AP MLD and the STAs in the STA MLD, and the APs in the AP MLD and the STAs in the STA MLD may communicate through corresponding links.

[0114] In some embodiments, an AP is a device deployed in a WLAN / Wi-Fi system to provide wireless communication capabilities for STAs. STAs may be: User Equipment (UE), Access Terminal, Subscriber Unit, Subscriber Station, Mobile Station, Mobile Station, Remote Station, Remote Terminal, Mobile Device, Wireless Communication Device, User Agent, or User Equipment. STAs may also be cellular phones, cordless phones, Session Initiation Protocol (SIP) phones, Wireless Local Loop (WLL) stations, Personal Digital Assistants (PDAs), handheld devices with wireless communication capabilities, computing devices or other processing devices connected to a wireless modem, vehicle-mounted devices, or wearable devices, but the embodiments of the present application are not limited thereto.

[0115] In some embodiments, both the AP and the non-AP STA support the IEEE 802.11 standard, but are not limited to the IEEE 802.11 standard.

[0116] FIG5 is a flow chart showing a link switching method provided by some exemplary embodiments of the present application. Taking the method executed by STA MLD as an example, the method includes at least some of the following steps:

[0117] Step 520: During the process of switching the first source link to the first target link, power control information is sent.

[0118] In the embodiment of the present application, STA represents a Non-AP STA, and STA MLD represents a Non-AP STA MLD.

[0119] In the embodiment of the present application, the STA MLD includes one or more non-AP STAs that support MLO capability. The non-AP STAs included in the STA MLD may also be referred to as subordinate non-AP STAs or subordinate STAs of the STA MLD.

[0120] Similarly, an AP MLD includes one or more APs that support MLO capabilities. The APs included in an AP MLD can also be called subordinate AP STAs or subordinate APs of the AP MLD.

[0121] At least two links exist between the AP MLD and the STA MLD. That is, the AP MLD and the STA MLD can operate simultaneously on at least two links. In some embodiments, the at least two links between the AP MLD and the STA MLD are in the same frequency band, such as both being in a low frequency band or both being in a millimeter wave band; or the at least two links between the AP MLD and the STA MLD are in different frequency bands, such as at least one link being in a low frequency band and at least one other link being in a millimeter wave band.

[0122] Among them, links operating in millimeter wave frequency bands can be simply referred to as millimeter wave links, and links operating in non-millimeter wave frequency bands can be simply referred to as non-millimeter wave links. Non-millimeter wave frequency bands are frequency bands other than millimeter wave bands, such as the Sub-7 GHz frequency band, or new frequency bands that may be planned in the future that are different from millimeter wave bands. This application does not limit this.

[0123] The first source link is at least one link corresponding to the STA MLD and the source AP MLD, that is, at least one link between the STA MLD and the source AP MLD. The source AP MLD is also called the current AP MLD; therefore, the first source link can also be called the first current link. The source AP MLD is the AP MLD currently associated with the STA MLD, that is, the AP MLD that has established a connection with the STA MLD, and that is, the AP MLD with which the STA MLD was associated before roaming.

[0124] The first target link is at least one link corresponding to a STA MLD and a target AP MLD, that is, at least one link between the STA MLD and the target AP MLD. The target AP MLD is the AP MLD with which the STA MLD wishes to associate, that is, the AP MLD with which the STA MLD wishes to establish a connection, that is, the AP MLD with which the STA MLD will associate, that is, the AP MLD with which the STA MLD will establish a connection, and that is, the AP MLD with which the STA MLD will associate after roaming.

[0125] Switching the first source link to the first target link may also be understood as the STA MLD roaming from the source AP MLD corresponding to the first source link to the target AP MLD corresponding to the first target link.

[0126] The power control information is used to control the transmit power of the candidate AP MLD or the target AP MLD, or to adjust the transmit power of the candidate AP MLD or the target AP MLD. The target AP MLD is one of the candidate AP MLDs.

[0127] In some embodiments, before executing step 520, the STA MLD determines the target AP MLD. Exemplarily, the STA MLD determines the target AP MLD based on the scan results, or based on pre-configured information, or based on the agreement of the communication protocol, or based on information from the source AP MLD. Step 520 can be implemented as follows: during the process of switching the first source link to the first target link, the STA MLD sends power control information to the target AP MLD. The power control information is used to control the transmit power of the target AP MLD. This design can improve the reliability of the first target link while minimizing interference within the communication system, reducing the impact on service transmission on other links, and ensuring communication quality within the communication system.

[0128] In some embodiments, the STA MLD uses a soft handover-based link switching method. Soft handover is link switching implemented using seamless roaming technology. During roaming from a source AP MLD to a target AP MLD, the STA MLD maintains a connection with the source AP MLD, i.e., maintains at least one link between the STA MLD and the source AP MLD in an operational state. Simultaneously, the STA MLD establishes a connection with the target AP MLD, i.e., establishes at least one new link with the target AP MLD.

[0129] In summary, the method provided in the embodiment of the present application supports the STA MLD to control the transmit power of the candidate AP MLD by sending power control information during the link switching process, so that the first target link between the STA MLD and the target AP MLD has higher reliability.

[0130] FIG6 shows a flowchart of a link switching method provided by some exemplary embodiments of the present application. Taking the method executed by STA MLD as an example, the method includes at least some of the following steps:

[0131] Step 601: Sending power control information during the process of switching a first source link to a first target link;

[0132] In some embodiments, step 601 may be implemented as step 601a or step 601b.

[0133] Step 601a: Send first power indication information to the candidate AP MLD;

[0134] In some embodiments, the power control information includes first power indication information, which is used to adjust or control the transmit power of the candidate AP MLD.

[0135] In the embodiment of the present application, the candidate AP MLD is an AP MLD different from the source AP MLD. The candidate AP MLD includes at least one of the following: an adjacent AP MLD of the source AP MLD, an AP MLD located on the same physical device as the source AP MLD, an AP MLD located within the signal coverage of the source AP MLD, an AP MLD located within the wireless medium coverage of the source AP MLD, an AP MLD that can be identified by the source AP MLD, an AP MLD located within the signal coverage of the STA MLD, an AP MLD located within the wireless medium coverage of the STA MLD, an AP MLD that can be identified by the STA MLD, a pre-configured candidate AP MLD, and a candidate AP MLD agreed upon by the communication protocol.

[0136] In some embodiments, the first power indication information is carried in a first frame for transmission; the first frame includes at least one of an element identification field, a length field, an element identification extension field, a transmit power field, and a target receive power field. The transmit power field indicates the current (i.e., first frame transmitted) transmit power value of the STA MLD; and the target receive power field indicates the receive power that the STA MLD expects to measure when receiving a signal sent by a sender (e.g., a candidate AP MLD).

[0137] In some embodiments, the STA MLD starts active scanning of the first target link when executing step 601a; or, the STA MLD starts active scanning of the first target link after executing step 601a; or, the STA MLD executing step 601a means that the STA MLD starts active scanning of the first target link.

[0138] Step 601b: Sending first power control trigger information to the source AP MLD;

[0139] In some embodiments, the power control information includes first power control trigger information, which is used to trigger the source AP MLD to send first power indication information to the candidate AP MLD, and the first power indication information is used to adjust or control the transmit power of the candidate AP MLD.

[0140] In some embodiments, the first power control trigger information is transmitted on a second source link, where the second source link is at least one link corresponding to the STA MLD and the source AP MLD except the first source link.

[0141] In some embodiments, the first power control trigger information is carried in a third frame for transmission; wherein the third frame includes at least one of a category field, an action field, a link identification field, a dialog token field, an element identification field, a length field, an element identification extension field, an AP MLD information field, etc.

[0142] In some embodiments, the AP MLD information field includes at least one of an AP MLD address field and a power field.

[0143] In some embodiments, the value of the action field includes at least one of the following:

[0144] The first value indicates that the third frame is used to indicate the first power control trigger information;

[0145] The second value indicates that the third frame includes a power upload indication;

[0146] The third value indicates that the third frame includes the target AP MLD confirmation indication;

[0147] The fourth value indicates that the third frame includes a target AP MLD association completion indication.

[0148] In some embodiments, the first power indication information is carried in a fourth frame for transmission, wherein the fourth frame includes at least one of a trigger type field, an uplink length field, a common information field determined by the trigger type, and a reserved field.

[0149] In some embodiments, the common information field determined by the trigger type includes at least one of a link identification field, a power field, and a life time field. The link identification field indicates the identification of the first target link, the power field indicates the transmit power value to which the candidate AP MLD needs to adjust on the first target link, and the life time field indicates how long the candidate AP MLD needs to use the transmit power value to which it needs to adjust.

[0150] In some embodiments, when executing step 601b, the STA MLD starts passive scanning of the first target link; or, after executing step 601b, the STA MLD starts passive scanning of the first target link; or, the STA MLD executing step 601b means that the STA MLD starts passive scanning of the first target link.

[0151] Step 602: Receive power information of the candidate AP MLD;

[0152] The power information of the candidate AP MLD includes at least one of the following: a fourth power value; a fifth power value; and a third power value.

[0153] Among them, the fourth power value is the transmit power value adjusted by the candidate AP MLD based on the power control information, that is, the fourth power value is the transmit power value adjusted by the candidate AP MLD based on the power control information on the first target link, that is, the current transmit power of the candidate AP MLD on the first target link; the fifth power value is the target receive power value of the candidate AP MLD on the first target link, that is, the fifth power value is the receive power that the candidate AP MLD expects to be measured when receiving a signal sent by a sender (such as a STA MLD) on the first target link; the third power value is the maximum transmit power value of the candidate AP MLD on the first target link, that is, the third power value is the maximum transmit power value that the candidate AP MLD can adopt on the first target link while meeting regulatory requirements and based on its own status (such as power supply status).

[0154] In some embodiments, the power information of the candidate AP MLD is carried in a second frame for transmission, wherein the second frame includes at least one of an element identification field, a length field, an element identification extension field, a transmit power field, a target receive power field, and a maximum power field. The transmit power field indicates the fourth power value of the candidate AP MLD; the target receive power field indicates the fifth power value of the candidate AP MLD; and the maximum power field indicates the third power value of the candidate AP MLD.

[0155] Step 603: Determine a first power value and / or a second power value based on the power information of the candidate AP MLD;

[0156] In some embodiments, step 603 is implemented as step 603a, or as step 603b, or as step 603c.

[0157] Step 603a: Determine a first power value based on the power information of the candidate AP MLD.

[0158] Step 603b: Determine a second power value based on the power information of the candidate AP MLD.

[0159] Step 603c: Determine a first power value and a second power value based on the power information of the candidate AP MLD.

[0160] The first power value is a transmit power value required by the STA MLD in the first target link when the STA MLD establishes a first target link with the target AP MLD.

[0161] The second power value is a transmit power value required by the candidate AP MLD in the first target link when the candidate AP MLD establishes the first target link with the STA MLD.

[0162] In some embodiments, the first power value is calculated by the STA MLD, or is calculated by the source AP MLD and sent to the STA MLD.

[0163] In some embodiments, the power information of the candidate AP MLD includes at least one of a fourth power value, a fifth power value, and a third power value; the STA MLD calculates the first power value and the second power value based on at least one of the fourth power value, the fifth power value, and the third power value.

[0164] In some embodiments, the STA MLD sends the identification information of the candidate AP MLD and the calculated corresponding second power value to the source AP MLD.

[0165] In some embodiments, the power information of the candidate AP MLD includes at least one of a fourth power value, a fifth power value, and a third power value; the STA MLD sends the power information of the candidate AP MLD, a sixth power value, and a seventh power value to the source AP MLD, where the sixth power value is an expected receiving power value of the STA MLD on the first target link, and the seventh power value is a receiving power value measured by the STA MLD when receiving a signal sent by a sender (such as the candidate AP MLD) on the first target link; and the STA MLD receives the first power value and the second power value sent by the source AP MLD.

[0166] In some embodiments, the power information of the candidate AP MLD includes at least one of a fifth power value, a third power value, and a second power value; the STA MLD calculates the first power value based on at least one of the fifth power value, the third power value, and the second power value.

[0167] The first power value includes the sum of the path loss and the fifth power value, the second power value includes the sum of the path loss and the sixth power value, and the path loss includes the difference between the fourth power value and the seventh power value.

[0168] Step 604: Determine the target AP MLD;

[0169] In some embodiments, a target AP MLD is determined based on the second power value and the third power value.

[0170] In some embodiments, a target AP MLD is determined from the candidate AP MLDs based on a magnitude relationship between the second power value and the third power value.

[0171] Exemplarily, when the second power value is less than or equal to the third power value, that is, Pa≤Pmax, the candidate AP MLD corresponding to the third power value greater than or equal to the second power value is the target AP MLD, and the STA MLD can establish a first target link with the target AP MLD.

[0172] In some embodiments, a target AP MLD is determined from the candidate AP MLDs based on the priority scores. The target AP MLD is the AP MLD with the highest priority score among the candidate AP MLDs. The priority score is determined based on the power information of the candidate AP MLD and the second power value.

[0173] In some embodiments, the priority score is the difference between a first product and a second sum. The first product is the product of the third power value corresponding to the candidate AP MLD and the first weight, the second sum is the sum of the second product and the third product, the second product is the product of the path loss and the second weight, and the third product is the product of the second power value and the third weight. The sum of the first, second, and third weights is 1 or 100%.

[0174] Step 605: Switch the first source link to the first target link;

[0175] The STA MLD establishes a first target link with the target AP MLD based on the first power value.

[0176] In some embodiments, the STA MLD uses the FT technology to establish a first target link with the target AP MLD. Exemplarily, the STA MLD uses a first power value to send an authentication request and a reassociation request to the target AP MLD, and the target AP MLD uses a second power value to send an authentication response and a reassociation response to the STA MLD, thereby completing the establishment of the first target link. Alternatively, the STA MLD sends an authentication request to the source AP MLD, and the target AP MLD sends an authentication response to the source AP MLD, and the STA MLD uses the first power value to send a reassociation request to the target AP MLD, and the target AP MLD uses the second power value to send a reassociation response to the STA MLD, thereby completing the establishment of the first target link.

[0177] Step 606: Send the second power indication information to the candidate AP MLD.

[0178] The candidate AP MLDs include the target AP MLD and other candidate AP MLDs, where the other candidate AP MLDs are AP MLDs other than the target AP MLD.

[0179] In some embodiments, the STA MLD sends the second power indication information to other candidate AP MLDs; or, the STA MLD sends the second power indication information to other candidate AP MLDs and the target AP MLD.

[0180] The second power indication information is used to restore the transmit power of the candidate AP MLD. In other words, it is used to restore the transmit power of the candidate AP MLD from the fourth power value to the transmit power value before receiving the first power indication information. This step enables other candidate AP MLDs to restore their original transmit power, reducing power consumption of other candidate AP MLDs and thereby minimizing negative impacts of link switching on the communication system, such as signal interference.

[0181] In some embodiments, the first power indication information indicates a holding time, that is, the effective time of the first power indication information. After the holding time ends, the candidate AP MLD automatically restores the transmission power, thereby reducing power consumption waste and reducing the negative impact of link switching on the communication system.

[0182] Step 607: Based on the first target link, switch the second source link to the second target link;

[0183] The second source link is at least one link corresponding to the STA MLD and the source AP MLD except the first source link, and the second target link is at least one link corresponding to the STA MLD and the target AP MLD except the first target link.

[0184] Switching the second source link to the second target link may also be understood as the STA MLD roaming from the source AP MLD corresponding to the second source link to the target AP MLD corresponding to the second target link.

[0185] In some embodiments, the STA MLD establishes a second target link with the target AP MLD using FT technology. For example, the STA MLD sends an authentication request and a reassociation request to the target AP MLD on the first target link. The STA MLD receives an authentication response and a reassociation response sent by the target AP MLD on the first target link, thereby completing the establishment of the second target link, i.e., completing the handover from the second source link to the second target link.

[0186] It should be understood that in the embodiments of the present application, steps 606 and 607 are optional steps. Steps 603 and 604 can be combined into one step, and steps 605 and 606 can be combined into one step. The execution order of each step can be adaptively adjusted according to the specific situation. For example, step 607 can be performed before step 606, and step 606 can be performed before step 605.

[0187] In summary, the method provided by the embodiment of the present application supports STA MLD to control the transmit power of the candidate AP MLD by sending power control information during the link switching process to achieve active scanning or passive scanning of the first target link. The link switching method has high flexibility, and the first target link established on this basis also has high reliability. Moreover, during the period of switching the first source link to the first target link, maintaining the connection between the STA MLD and the source AP MLD can avoid the problem of data transmission interruption during the link switching process, reduce the possibility of users perceiving data transmission interruption, and improve user experience. In addition, STA MLD can also establish a second target link based on the established first target link, so that roaming from the source AP MLD to the target AP MLD has high reliability and high simplicity.

[0188] FIG7 shows a flowchart of a link switching method provided by some exemplary embodiments of the present application. Taking the method executed by the target AP MLD as an example, the method includes at least some of the following steps:

[0189] Step 720: Receive power control information during the process of switching the first source link to the first target link.

[0190] The first source link is at least one link corresponding to the STA MLD and the source AP MLD, that is, at least one link between the STA MLD and the source AP MLD. The source AP MLD is also called the current AP MLD; therefore, the first source link can also be called the first current link. The source AP MLD is the AP MLD currently associated with the STA MLD, that is, the AP MLD that has established a connection with the STA MLD, and that is, the AP MLD with which the STA MLD was associated before roaming.

[0191] The first target link is at least one link corresponding to a STA MLD and a target AP MLD, that is, at least one link between the STA MLD and the target AP MLD. The target AP MLD is the AP MLD with which the STA MLD wishes to associate, that is, the AP MLD with which the STA MLD wishes to establish a connection, that is, the AP MLD with which the STA MLD will associate, that is, the AP MLD with which the STA MLD will establish a connection, and that is, the AP MLD with which the STA MLD will associate after roaming.

[0192] Switching the first source link to the first target link may also be understood as the STA MLD roaming from the source AP MLD corresponding to the first source link to the target AP MLD corresponding to the first target link.

[0193] The power control information is used to control the transmit power of the candidate AP MLD or the target AP MLD, or to adjust the transmit power of the candidate AP MLD or the target AP MLD. The target AP MLD is one of the candidate AP MLDs.

[0194] In some embodiments, the STA MLD uses a soft handover-based link switching method. Soft handover is link switching implemented using seamless roaming technology. During roaming from a source AP MLD to a target AP MLD, the STA MLD maintains a connection with the source AP MLD, i.e., maintains at least one link between the STA MLD and the source AP MLD in an operational state. Simultaneously, the STA MLD establishes a connection with the target AP MLD, i.e., establishes at least one new link with the target AP MLD.

[0195] In some embodiments, the power control information is sent by the STA MLD, or by the source AP MLD.

[0196] In some embodiments, the candidate AP MLD adjusts the transmit power to a fourth power value based on the power control information, and uses the fourth power value to send the power information of the candidate AP MLD.

[0197] It should be understood that the link switching method shown in FIG. 7 may also be executed by a candidate AP MLD, to which the target AP belongs.

[0198] In summary, the method provided in the embodiments of the present application supports the candidate AP MLD to adjust the transmit power based on power control information during the link switching process, thereby ensuring that the first target link established between the STA MLD and the target AP MLD in the candidate AP MLD has high reliability. Furthermore, while the first source link is switched to the first target link, maintaining the connection between the STA MLD and the source AP MLD can avoid data transmission interruptions during the link switching process, reduce the possibility of users perceiving data transmission interruptions, and improve the user experience.

[0199] FIG8 is a flow chart showing a link switching method provided by some exemplary embodiments of the present application. Taking the method executed by the target AP MLD as an example, the method includes at least some of the following steps:

[0200] Step 810: Receive power control information during the process of switching from the first source link to the first target link;

[0201] In some embodiments, the power control information includes first power indication information, which is used to adjust or control the transmit power of the candidate AP MLD.

[0202] In some embodiments, the candidate AP MLD receives the first power indication information sent by the STA MLD. That is, the STA MLD sends the first power indication information to the candidate AP MLD in an active scanning manner.

[0203] In some embodiments, the first power indication information is carried in a first frame for transmission; the first frame includes at least one of an element identification field, a length field, an element identification extension field, a transmit power field, and a target receive power field. The transmit power field indicates the current (i.e., first frame transmitted) transmit power value of the STA MLD; and the target receive power field indicates the receive power that the STA MLD expects to measure when receiving a signal sent by a sender (e.g., a candidate AP MLD).

[0204] In some embodiments, the candidate AP MLD receives the first power indication information sent by the source AP MLD. That is, the STA MLD indirectly sends the first power indication information to the candidate AP MLD through the source AP MLD in a passive scanning manner.

[0205] In some embodiments, the first power indication information is carried in a fourth frame for transmission, wherein the fourth frame includes at least one of a trigger type field, an uplink length field, a common information field determined by the trigger type, and a reserved field.

[0206] In some embodiments, the common information field determined by the trigger type includes at least one of a link identification field, a power field, and a holding time field. The link identification field indicates the identification of the first target link, the power field indicates the transmit power value to which the candidate AP MLD needs to adjust on the first target link, and the holding time field indicates the period of time during which the candidate AP MLD needs to use the transmit power value to which it needs to adjust.

[0207] Step 820: Send the power information of the candidate AP MLD;

[0208] The power information of the candidate AP MLD includes at least one of the following: a fourth power value; a fifth power value; and a third power value.

[0209] Among them, the fourth power value is the transmit power value of the candidate AP MLD on the first target link adjusted based on the power control information, that is, the fourth power value is the current transmit power of the candidate AP MLD on the first target link; the fifth power value is the target receive power value of the candidate AP MLD on the first target link, that is, the fifth power value is the receive power that the candidate AP MLD expects to be measured when receiving a signal sent by a sender (such as a STA MLD) on the first target link; the third power value is the maximum transmit power value of the candidate AP MLD on the first target link, that is, the third power value is the maximum transmit power value that the candidate AP MLD can adopt on the first target link while meeting regulatory requirements and based on its own status (such as power supply status).

[0210] In some embodiments, the power information of the candidate AP MLD is carried in a second frame for transmission, wherein the second frame includes at least one of an element identification field, a length field, an element identification extension field, a transmit power field, a target receive power field, and a maximum power field. The transmit power field indicates the fourth power value of the candidate AP MLD; the target receive power field indicates the fifth power value of the candidate AP MLD; and the maximum power field indicates the third power value of the candidate AP MLD.

[0211] In some embodiments, the candidate AP MLD calculates a second power value. The second power value is a transmit power value required by the candidate AP MLD in the first target link when the candidate AP MLD establishes the first target link with the STA MLD.

[0212] Step 830: Establish a first target link;

[0213] The target AP MLD establishes a first target link with the STA MLD.

[0214] The target AP MLD is one of the candidate AP MLDs.

[0215] In some embodiments, the STA MLD calculates the second power value. In some embodiments, the target AP MLD is an AP MLD among the candidate AP MLDs corresponding to a third power value greater than or equal to the second power value.

[0216] In some embodiments, the target AP MLD is an AP MLD with the highest priority score among the candidate AP MLDs. The priority score is determined based on the power information of the candidate AP MLD and the second power value.

[0217] In some embodiments, the priority score is the difference between a first product and a second sum. The first product is the product of the third power value corresponding to the candidate AP MLD and the first weight, the second sum is the sum of the second product and the third product, the second product is the product of the path loss and the second weight, and the third product is the product of the second power value and the third weight. The sum of the first, second, and third weights is 1 or 100%.

[0218] In some embodiments, the target AP MLD establishes a first target link with the STA MLD using the FT technology. For example, the STA MLD sends an authentication request and a reassociation request to the target AP MLD using a first power value, and the target AP MLD sends an authentication response and a reassociation response to the STA MLD using a second power value, thereby completing the establishment of the first target link. Alternatively, the STA MLD sends an authentication request to the source AP MLD, the target AP MLD sends an authentication response to the source AP MLD, the STA MLD sends a reassociation request to the target AP MLD using the first power value, and the target AP MLD sends a reassociation response to the STA MLD using the second power value, thereby completing the establishment of the first target link.

[0219] Step 840: Restore transmit power.

[0220] In some embodiments, the first power indication information indicates a holding time, that is, the effective time of the first power indication information. After the holding time ends, the candidate AP MLD automatically restores the transmission power, thereby reducing power consumption waste and reducing the negative impact of link switching on the communication system.

[0221] In some embodiments, the candidate AP MLD receives second power indication information from the source AP MLD or the STA MLD. The second power indication information is used to restore the transmit power of the candidate AP MLD, that is, to restore the transmit power of the candidate AP MLD from the fourth power value to the transmit power value before receiving the first power indication information. The candidate AP MLD restores the transmit power based on the received second power indication information.

[0222] Step 850: Establish a second target link based on the first target link;

[0223] The second target link is at least one link corresponding to the STA MLD and the target AP MLD except the first target link.

[0224] In some embodiments, the STA MLD establishes a second target link with the target AP MLD using FT technology. For example, the STA MLD sends an authentication request and a reassociation request to the target AP MLD on the first target link. The STA MLD receives an authentication response and a reassociation response sent by the target AP MLD on the first target link, thereby completing the establishment of the second target link, i.e., completing the handover from the second source link to the second target link.

[0225] It should be understood that in the embodiments of the present application, steps 830 and 840 are optional steps. Steps 810 and 820 can be combined into one step, and steps 830 and 840 can be combined into one step. The execution order of each step can be adaptively adjusted according to the specific situation. For example, step 840 can be performed before step 830, and step 850 can be performed before step 840.

[0226] It should be understood that some or all of the steps in the link switching method shown in FIG8 may also be performed by a candidate AP MLD, and the target AP MLD is a candidate AP MLD. For example, the candidate AP MLD may perform steps 810, 820, and 850, and may also participate in steps 830 and 840.

[0227] In summary, the method provided in the embodiment of the present application supports the candidate AP MLD to adjust the transmit power based on power control information during the link switching process, and supports the STA MLD to establish a connection with the target AP MLD in the candidate AP MLD through active scanning or passive scanning. The link switching method has high flexibility and improves the reliability of the first target link between the STA MLD and the target AP MLD. In addition, during the switching of the first source link to the first target link, maintaining the connection between the STA MLD and the source AP MLD can avoid data transmission interruption problems during the link switching process, reduce the possibility of users perceiving data transmission interruption, and improve user experience.

[0228] FIG9 is a flow chart showing a link switching method provided by some exemplary embodiments of the present application. Taking the method executed by the source AP MLD as an example, the method includes at least some of the following steps:

[0229] Step 920: Transmit power control information during the process of switching the first source link to the first target link.

[0230] In the embodiments of the present application, transmission can be understood as reception, or as sending, or as both reception and sending.

[0231] The first source link is at least one link corresponding to the STA MLD and the source AP MLD, that is, at least one link between the STA MLD and the source AP MLD. The source AP MLD is also called the current AP MLD; therefore, the first source link can also be called the first current link. The source AP MLD is the AP MLD currently associated with the STA MLD, that is, the AP MLD that has established a connection with the STA MLD, and that is, the AP MLD with which the STA MLD was associated before roaming.

[0232] The first target link is at least one link corresponding to a STA MLD and a target AP MLD, that is, at least one link between the STA MLD and the target AP MLD. The target AP MLD is the AP MLD with which the STA MLD wishes to associate, that is, the AP MLD with which the STA MLD wishes to establish a connection, that is, the AP MLD with which the STA MLD will associate, that is, the AP MLD with which the STA MLD will establish a connection, and that is, the AP MLD with which the STA MLD will associate after roaming.

[0233] Switching the first source link to the first target link may also be understood as the STA MLD roaming from the source AP MLD corresponding to the first source link to the target AP MLD corresponding to the first target link.

[0234] The power control information is used to control the transmit power of the candidate AP MLD or the target AP MLD, or to adjust the transmit power of the candidate AP MLD or the target AP MLD. The target AP MLD is one of the candidate AP MLDs.

[0235] In some embodiments, the STA MLD uses a soft handover-based link switching method. Soft handover is link switching implemented using seamless roaming technology. During roaming from a source AP MLD to a target AP MLD, the STA MLD maintains a connection with the source AP MLD, i.e., maintains at least one link between the STA MLD and the source AP MLD in an operational state. Simultaneously, the STA MLD establishes a connection with the target AP MLD, i.e., establishes at least one new link with the target AP MLD.

[0236] In summary, the method provided in the embodiments of the present application supports the source AP MLD transmitting power control information during the link switching process to control the transmit power of the candidate AP MLD, thereby ensuring that the first target link between the STA MLD and the target AP MLD has high reliability. Furthermore, while the first source link is switched to the first target link, maintaining the connection between the STA MLD and the source AP MLD can avoid data transmission interruptions during the link switching process, reduce the possibility of users perceiving data transmission interruptions, and improve the user experience.

[0237] FIG10 is a flow chart showing a link switching method provided by some exemplary embodiments of the present application. Taking the method executed by the source AP MLD as an example, the method includes at least some of the following steps:

[0238] Step 1010: Transmitting power control information during the process of switching the first source link to the first target link;

[0239] In some embodiments, step 1010 may be implemented as step 1010a and step 1010b.

[0240] Step 1010a: Receive first power control trigger information sent by STA MLD;

[0241] In some embodiments, the power control information includes first power control trigger information, which is used to trigger the source AP MLD to send first power indication information to the candidate AP MLD, and the first power indication information is used to adjust or control the transmit power of the candidate AP MLD.

[0242] In some embodiments, the first power control trigger information is transmitted on a second source link, where the second source link is at least one link corresponding to the STA MLD and the source AP MLD except the first source link.

[0243] In some embodiments, the first power control trigger information is carried in a third frame for transmission; wherein the third frame includes at least one of a category field, an action field, a link identification field, a dialogue token field, an element identification field, a length field, an element identification extension field, an AP MLD information field, etc.

[0244] In some embodiments, the AP MLD information field includes at least one of an AP MLD address field and a power field.

[0245] In some embodiments, the value of the action field includes at least one of the following:

[0246] The first value indicates that the third frame is used to indicate the first power control trigger information;

[0247] The second value indicates that the third frame includes a power upload indication;

[0248] The third value indicates that the third frame includes the target AP MLD confirmation indication;

[0249] The fourth value indicates that the third frame includes a target AP MLD association completion indication.

[0250] Step 1010b: Send first power indication information to the candidate AP MLD.

[0251] In some embodiments, the first power indication information is carried in a fourth frame for transmission, wherein the fourth frame includes at least one of a trigger type field, an uplink length field, a common information field determined by the trigger type, and a reserved field.

[0252] In some embodiments, the common information field determined by the trigger type includes at least one of a link identification field, a power field, and a holding time field. The link identification field indicates the identification of the first target link, the power field indicates the transmit power value to which the candidate AP MLD needs to adjust on the first target link, and the holding time field indicates the period of time during which the candidate AP MLD needs to use the transmit power value to which it needs to adjust.

[0253] Step 1020: Determine a first power value;

[0254] The first power value is a transmit power value required by the STA MLD in the first target link when the STA MLD establishes a first target link with the target AP MLD.

[0255] In some embodiments, the power information of the candidate AP MLD includes at least one of a fourth power value, a fifth power value, and a third power value; the source AP MLD receives the power information of the candidate AP MLD, a sixth power value, and a seventh power value sent by the STA MLD, where the sixth power value is an expected receive power value of the STA MLD on the first target link; the source AP MLD calculates the first power value and the second power value based on the power information of the candidate AP MLD, the sixth power value, and the seventh power value; and the source AP MLD sends the first power value and the second power value to the STA MLD.

[0256] Among them, the third power value is the maximum transmit power value of the candidate AP MLD on the first target link, that is, the third power value is the maximum transmit power value that the candidate AP MLD can use on the first target link while meeting regulatory requirements and based on its own status (for example, power supply status); the fourth power value is the transmit power value adjusted by the candidate AP MLD based on the power control information, that is, the fourth power value is the transmit power value adjusted by the candidate AP MLD on the first target link based on the power control information, that is, the current transmit power of the candidate AP MLD on the first target link; the fifth power value is the target receive power value of the candidate AP MLD on the first target link, that is, the fifth power value is the receive power that the candidate AP MLD expects to be measured when the first target link receives a signal sent by a sender (for example, a STA MLD); the sixth power value is the expected receive power value of the STA MLD on the first target link; and the seventh power value is the receive power value measured when the STA MLD receives a signal sent by the sender (for example, the candidate AP MLD) on the first target link.

[0257] In some embodiments, the source AP MLD receives the first power value and the second power value sent by the STA MLD.

[0258] Step 1030: Send third power indication information to the candidate AP MLD;

[0259] The third power indication information is used to instruct the candidate AP MLD to maintain the transmit power adjusted based on the first power indication information.

[0260] Step 1040: Receive second power control trigger information sent by the STA MLD;

[0261] The second power control triggering information is used to trigger the source AP MLD to send second power indication information to other candidate AP MLDs.

[0262] Step 1050: Send second power indication information to the candidate AP MLD;

[0263] The candidate AP MLDs include the target AP MLD and other candidate AP MLDs, where the other candidate AP MLDs are AP MLDs other than the target AP MLD.

[0264] In some embodiments, the STA MLD sends the second power indication information to other candidate AP MLDs; or, the STA MLD sends the second power indication information to other candidate AP MLDs and the target AP MLD.

[0265] The second power indication information is used to restore the transmit power of the candidate AP MLD. In other words, it is used to restore the transmit power of the candidate AP MLD from the fourth power value to the transmit power value before receiving the first power indication information. This step enables other candidate AP MLDs to restore their original transmit power, reducing power consumption of other candidate AP MLDs and thus minimizing the negative impact of link switching on the communication system.

[0266] Step 1060: Receive the authentication request sent by the STA MLD;

[0267] The authentication request is used to perform authentication between the STA MLD and the target AP MLD, thereby establishing a first target link.

[0268] Step 1070: Send an authentication request to the target AP MLD;

[0269] The source AP MLD synchronizes the authentication request from the STA MLD to the target AP MLD.

[0270] Step 1080: Receive an authentication response sent by the target AP MLD;

[0271] The authentication response is used to indicate the response of the target AP MLD to the authentication request from the STA MLD.

[0272] Step 1090: Send an authentication response to the STA MLD.

[0273] The source AP MLD synchronizes the authentication response from the target AP MLD to the STA MLD.

[0274] It should be understood that in the embodiment of the present application, steps 1030 to 1090 are optional steps. Steps 1040 and 1050 can be combined into one step, steps 1060 and 1070 can be combined into one step, and steps 1080 and 1090 can be combined into one step. The execution order of each step can be adaptively adjusted according to the specific situation. For example, step 1030 can be performed before step 1020, and steps 1040 and 1050 can be performed after step 1090.

[0275] In summary, the method provided in the embodiments of the present application supports the source AP MLD controlling the transmit power of the candidate AP MLD by transmitting power control information during the link switching process, thereby ensuring a high reliability of the first target link between the STA MLD and the target AP MLD. Furthermore, while the first source link is switched to the first target link, maintaining the connection between the STA MLD and the source AP MLD can avoid data transmission interruptions during the link switching process, reduce the likelihood of users perceiving data transmission interruptions, and improve the user experience.

[0276] Figure 11 shows a schematic diagram of a link switching method provided by some exemplary embodiments of the present application. Assume that two links are established between the STA MLD and the source AP MLD 1101, namely the first source link 1102 and the second source link 1103. The embodiment of the present application takes the first source link 1102 as a link operating at 5 GHz and the second source link 1103 as a link operating at 2.4 GHz as an example for illustration, but does not mean to limit the operating frequency bands of the first source link 1102 and the second source link 1103. The first source link 1102 and the second source link 1103 can operate in frequency bands other than 2.4 GHz and 5 GHz, such as millimeter wave bands and 6 GHz bands, or they can operate in the same frequency band.

[0277] When a STA 1104 in a STA MLD moves, the link corresponding to STA 1104 may need to be switched to ensure communication quality. For example, when STA 1104 reaches the signal overlap area between candidate AP MLD 1105 and source AP MLD 1101, STA 1104 maintains its connection to source AP MLD 1101 on second source link 1103 while simultaneously establishing first target link 1106 with candidate AP MLD 1105. During the switching process from first source link 1102 to first target link 1106, STA 1104 adjusts the transmit power of candidate AP MLD 1105 by sending power control information, for example, increasing the transmit power of candidate AP MLD 1105. Sending power control information can significantly improve the reliability of first target link 1106 between STA 1104 and candidate AP MLD 1105, compared to not sending power control information.

[0278] FIG12 is a flowchart illustrating a link switching method provided by some exemplary embodiments of the present application. Taking the method performed by the STA MLD, the source AP MLD, and the candidate AP MLD as an example, the method includes at least some of the following steps:

[0279] Step 1201: A connection is established between the STA MLD and the source AP MLD.

[0280] The STA MLD is associated with the source AP MLD. The STA MLD and the source AP MLD can transmit signaling, data, and frames.

[0281] Step 1202: disconnect the first source link between the STA MLD and the source AP MLD;

[0282] In the embodiment of the present application, an example is provided in which at least a first source link and a second source link are included between the STA MLD and the source AP MLD, where the first source link is at least one link between the STA MLD and the source AP MLD, and the second source link is at least another link between the STA MLD and the source AP MLD.

[0283] In some embodiments, the STA MLD autonomously disconnects the first source link between the STA MLD and the source AP MLD; or, when the communication quality of the first source link is lower than a first threshold, the STA MLD disconnects the first source link; or, when the communication quality of the first source link is lower than a second threshold, the first source link is automatically disconnected.

[0284] The communication quality may be represented by at least one of a received signal strength indicator (RSSI) value, a packet loss rate, a retransmission rate, a number of packet losses, a number of retransmissions, a number of transmission failures, and the like.

[0285] Step 1203: The STA MLD sends first power indication information to the candidate AP MLD;

[0286] The candidate AP MLD is an AP MLD different from the source AP MLD. The candidate AP MLD includes at least one of the following: an AP MLD located on the same physical device as the source AP MLD, an AP MLD located within the signal coverage of the source AP MLD, an AP MLD located within the wireless medium coverage of the source AP MLD, an AP MLD located within the signal coverage of an STA MLD, an AP MLD located within the wireless medium coverage of a STA MLD, and a pre-configured candidate AP MLD.

[0287] The first power indication information is used to adjust or control the transmit power of the candidate AP MLD.

[0288] Adjusting or controlling the transmit power of the candidate AP MLD includes at least one of increasing the transmit power of the candidate AP MLD, decreasing the transmit power of the candidate AP MLD, maintaining the transmit power of the candidate AP MLD, etc. In the embodiment of the present application, the first power indication information is used to increase the transmit power of the candidate AP MLD as an example for schematic description.

[0289] In some embodiments, the STA MLD starts active scanning of the first target link when executing step 1203; or, the STA MLD starts active scanning of the first target link after executing step 1203; or, the STA MLD executing step 1203 means that the STA MLD starts active scanning of the first target link.

[0290] In some embodiments, the first power indication information further indicates the transmit power of the STA MLD.

[0291] In some embodiments, the first power indication information is carried in a first frame for transmission.

[0292] Figure 13 shows a schematic diagram of the format of a first frame provided by some exemplary embodiments of the present application. The number below a field indicates the number of bytes or bits of the field. The first frame includes at least one of an Element Identity (Element ID) field, a Length (Length) field, an Element ID Extension (Element ID Extension) field, a Transmit Power (TX Power) field, and a Target Receive Power (Target Receive Power) field.

[0293] In some embodiments, when the value of the element identification field is a value A, and / or the value of the element identification extension field is a value B, it indicates that the frame to which the element identification field and / or the element identification extension field belongs is the first frame. Exemplarily, the value A is 255 or other reserved values, and the value B is 98 or other reserved values.

[0294] In some embodiments, the target received power field in the first frame is used to indicate the expected received power Target of the STA MLD. pwr , which is calculated as follows: Target pwr =-110+F val (1)

[0295] Among them, F val Indicates the value of the target receiving power field, F val The value range is [0,90], and values ​​greater than 90 can be used as reserved values.

[0296] In some embodiments, the first frame includes a Probe Request frame.

[0297] It should be understood that the frame format shown in FIG13 is merely an example and not a limitation. The first frame may also carry fewer or more fields, such as only the transmit power field and the target receive power field, or only the element identifier field, the length field, the transmit power field, and the target receive power field, or a reserved field in addition to the five fields shown in FIG13 . The order of the fields shown in FIG13 may be adjusted based on actual circumstances, such as the target receive power field preceding the transmit power field, the element identifier extension field preceding the length field, or the length field following the target receive power field, etc. The number of bytes of the fields shown in FIG13 is variable, such as the transmit power field occupying 2 bytes, the target receive power field occupying 2 bytes, the element identifier field occupying 0 bytes, etc. The names of the fields shown in FIG13 are variable, such as the transmit power field or the power field, the target receive power field or the expected receive power field, the power field, etc.

[0298] In some embodiments, step 1203 is performed by the first STA. The first STA is the STA corresponding to the first source link in the STA MLD, that is, the STA corresponding to the first target link in the STA MLD.

[0299] Step 1204: The candidate AP MLD adjusts transmit power;

[0300] The candidate AP MLD increases its own transmit power to a fourth power value based on the received first power indication information.

[0301] In some embodiments, the candidate AP MLD calculates its own maximum transmit power value according to the current network status, that is, calculates the third power value.

[0302] In some embodiments, the candidate AP MLD calculates a second power value based on the value of the transmit power field and the target receive power field in the received first frame, and RSSI information corresponding to the first frame. The second power value is the transmit power value required by the candidate AP MLD when establishing a link with the STA MLD.

[0303] Step 1205: The candidate AP MLD sends the power information of the candidate AP MLD;

[0304] The power information of the candidate AP MLD includes at least one of a fourth power value, a fifth power value, a third power value, and a second power value. The fourth power value is the transmit power value adjusted by the candidate AP MLD on the first target link based on the power control information, that is, the current transmit power of the candidate AP MLD on the first target link; the fifth power value is the target receive power value of the candidate AP MLD on the first target link, that is, the fifth power value is the receive power that the candidate AP MLD expects to measure when receiving a signal sent by a sender (such as a STA MLD) on the first target link; and the third power value is the maximum transmit power value of the candidate AP MLD on the first target link, that is, the third power value is the maximum transmit power value that the candidate AP MLD can use on the first target link while meeting regulatory requirements and based on its own status (such as power supply status).

[0305] The candidate AP MLD uses the fourth power value to send the power information of the candidate AP MLD.

[0306] In some embodiments, the power information of the candidate AP MLD is carried in the second frame for transmission.

[0307] Figure 14 shows a schematic diagram of the format of a second frame provided by some exemplary embodiments of the present application. The number below a field indicates the number of bytes or bits in that field. The second frame includes at least one of an element identification field, a length field, an element identification extension field, a transmit power field, a target receive power field, and a maximum power field.

[0308] In some embodiments, when the value of the element identification field is a value A, and / or the value of the element identification extension field is a value C, it indicates that the frame to which the element identification field and / or the element identification extension field belongs is the second frame. Exemplarily, the value A is 255 or other reserved values, and the value C is 99 or other reserved values.

[0309] In some embodiments, the target received power field in the second frame is used to indicate the expected received power of the candidate AP MLD, and the calculation formula is referred to the aforementioned formula (1).

[0310] In some embodiments, the maximum power field in the second frame is used to indicate the maximum transmit power of the candidate AP MLD.

[0311] In some embodiments, the second frame includes a Probe Response frame.

[0312] It should be understood that the frame format shown in FIG14 is merely an example and not limiting. The second frame may also carry fewer or more fields, such as only the transmit power field and the target receive power field; or only the transmit power field, the target receive power field, and the maximum power field; or only the element identifier field, the length field, the transmit power field, the target receive power field, and the maximum receive power field; or a reserved field in addition to the six fields shown in FIG14 . The order of the fields shown in FIG14 may be adjusted based on actual circumstances, such as the target receive power field preceding the transmit power field, the element identifier extension field preceding the length field, the length field following the target receive power field, or the maximum power field preceding the transmit power field. The number of bytes of the fields shown in FIG14 is variable, such as the transmit power field occupying 2 bytes, the target receive power field occupying 2 bytes, the maximum power field occupying 0 bytes, the element identifier field occupying 0 bytes, etc. The names of the various fields shown in Figure 14 are variable, such as the transmit power field or the power field, the target receive power field or the expected receive power field, the power field, the maximum power field or the acceptable power threshold field, the acceptable maximum power field, and so on.

[0313] In some embodiments, step 1205 is performed by a first AP. The first AP is an AP corresponding to the first target link in the candidate AP MLD.

[0314] Step 1206: The STA MLD determines a first power value based on the power information of the candidate AP MLD.

[0315] The STA MLD scans the power information of the candidate AP MLD, or in other words, the STA MLD scans the second frame.

[0316] The first power value is a transmit power value required by the STA MLD in the first target link when the STA MLD establishes a first target link with the target AP MLD.

[0317] In some embodiments, the power information of the candidate AP MLD includes at least one of a fifth power value, a third power value, and a second power value; the STA MLD calculates the first power value based on at least one of the fifth power value, the third power value, and the second power value.

[0318] Assuming that the first power value is Ps and the second power value is Pa, the calculation formulas for the first power value and the second power value are as follows:

[0319] Where PL represents the path loss, Indicates the expected receive power of the candidate AP MLD when establishing the first target link; Indicates the expected receive power of the STA MLD when establishing the first target link; Indicates the transmit power of the second frame, that is, the transmit power used by the candidate AP MLD to send the second frame; Rx pwr Indicates the received power of the second frame, that is, the received power corresponding to the STA MLD receiving the second frame.

[0320] Step 1207: Determine the target AP MLD;

[0321] In some embodiments, a target AP MLD is determined based on the second power value and the third power value.

[0322] In some embodiments, a target AP MLD is determined from the candidate AP MLDs based on a magnitude relationship between the second power value and the third power value.

[0323] Exemplarily, when the second power value is less than or equal to the third power value, that is, Pa≤Pmax, the candidate AP MLD corresponding to the third power value greater than or equal to the second power value is the target AP MLD, and the STA MLD can establish a first target link with the target AP MLD.

[0324] In some embodiments, a target AP MLD is determined from the candidate AP MLDs based on the priority scores. The target AP MLD is the AP MLD with the highest priority score among the candidate AP MLDs. The priority score is determined based on the power information of the candidate AP MLD and the second power value.

[0325] In some embodiments, the priority score is the difference between a first product and a second sum. The first product is the product of the third power value corresponding to the candidate AP MLD and the first weight, the second sum is the sum of the second product and the third product, the second product is the product of the path loss and the second weight, and the third product is the product of the second power value and the third weight. The sum of the first, second, and third weights is 1 or 100%.

[0326] Assuming that the first weight is α, the second weight is β, the third weight is γ, the third power value is Pmax, the path loss is PL, and the second power value is Pa, then the priority score Score is calculated as follows: Score = α·Pmax-β·PL-γ·Pa (5)

[0327] Here, α+β+γ=1, or α+β+γ=100%. Moreover, the value of α belongs to [0,1], the value of β belongs to [0,1], and the value of γ belongs to [0,1].

[0328] In some embodiments, the STA MLD may further send third power indication information to the candidate AP MLD; the third power indication information is used to instruct the candidate AP MLD to maintain the transmit power adjusted based on the first power indication information.

[0329] In some embodiments, the STA MLD sends the third power indication information to the candidate AP MLD before executing step 1207, or sends the third power indication information to the candidate AP MLD before executing step 1206, or sends the third power indication information to the candidate AP MLD after executing step 1206, or repeats step 1206 and sending the third power indication information to the candidate AP MLD before executing step 1207.

[0330] Step 1208: Establish a first target link;

[0331] A first target link is established between the STA MLD and the target AP MLD based on the first power value and the second power value.

[0332] Illustratively, step 1208 includes step 1208a, step 1208b, step 1208c, and step 1208d.

[0333] Step 1208a: STA MLD sends an authentication request;

[0334] In some embodiments, the STA MLD sends an authentication request to the source AP MLD, and the source AP MLD sends an authentication request to the target AP MLD; or, the STA MLD sends an authentication request to the target AP MLD.

[0335] In some embodiments, the STA MLD sends an authentication request to the target AP MLD using a first power value.

[0336] Step 1208b: The target AP MLD sends an authentication response.

[0337] In some embodiments, the target AP MLD sends an authentication response to the source AP MLD, and the source AP MLD sends an authentication response to the STA MLD; or, the target AP MLD sends an authentication response to the STA MLD.

[0338] In some embodiments, the target AP MLD sends an authentication response to the STA MLD using a second power value.

[0339] Step 1208c: The STA MLD sends a reassociation request to the target AP MLD;

[0340] In some embodiments, the STA MLD sends a reassociation request to the target AP MLD using a first power value.

[0341] Step 1208d: The target AP MLD sends a reassociation response to the STA MLD.

[0342] In some embodiments, the target AP MLD sends a reassociation response to the STA MLD using a second power value.

[0343] For details about authentication requests, authentication responses, reassociation requests, and reassociation responses, refer to the IEEE (Institute of Electrical and Electronics Engineers) 802.11r protocol.

[0344] Step 1209: Establish a second target link based on the first target link.

[0345] In some embodiments, the STA MLD autonomously disconnects the second source link between the STA MLD and the source AP MLD; or, when the communication quality of the second source link is lower than a third threshold, the STA MLD disconnects the second source link; or, when the communication quality of the second source link is lower than a fourth threshold, the second source link is automatically disconnected.

[0346] In some embodiments, the STA MLD sends a disassociation indication to the source AP MLD, where the disassociation indication is used to disassociate the STA MLD from the source AP MLD and / or disconnect the second source link.

[0347] In some embodiments, with the assistance of the first target link, the STA MLD establishes a second target link with the target AP MLD.

[0348] In some embodiments, the STA MLD establishes a second target link with the target AP MLD using the FT technology. For example, the STA MLD sends an authentication request to the target AP MLD on the first target link, the target AP MLD sends an authentication response to the STA MLD on the first target link, the STA MLD sends a reassociation request to the target AP MLD on the first target link, and the target AP MLD sends a reassociation response to the STA MLD on the first target link, thereby completing the establishment of the second target link, i.e., completing the handover from the second source link to the second target link.

[0349] It should be understood that in this embodiment of the present application, step 1209 is optional. Steps 1202 and 1203 can be combined into one step, and steps 1204 and 1205 can be combined into one step. The execution order of each step can be adaptively adjusted based on specific circumstances. Step 1206 can be executed repeatedly. That is, before determining the target AP MLD, the STA MLD can scan the power information of the candidate AP MLDs in real time and calculate the first power value multiple times until the target AP MLD is determined.

[0350] It should be understood that some or all of the steps in the link switching method shown in Figure 12 may also be performed by the target AP MLD, which is a candidate AP MLD. For example, the target AP MLD may perform steps 1204, 1205, 1208, and 1209, and may also participate in steps 1206, 1207, and so on.

[0351] In summary, the method provided by the embodiment of the present application supports STA MLD to control the transmit power of the candidate AP MLD by sending power control information during the link switching process, determines the target AP MLD among the candidate AP MLDs by active scanning, and establishes a first target link by controlling the transmit power of the target AP MLD and the transmit power of the STA MLD. The first target link established on this basis has high reliability. Moreover, during the period of switching the first source link to the first target link, maintaining the connection between the STA MLD and the source AP MLD can avoid the problem of data transmission interruption during the link switching process, reduce the possibility of users perceiving data transmission interruption, and improve user experience. In addition, STA MLD can also establish a second target link based on the established first target link, so that roaming from the source AP MLD to the target AP MLD has high reliability and high simplicity, greatly improving the efficiency and stability of the communication system and ensuring the communication quality.

[0352] FIG15 is a flowchart illustrating a link switching method provided by some exemplary embodiments of the present application. Taking the method performed by the STA MLD, the source AP MLD, and the candidate AP MLD as an example, the method includes at least some of the following steps:

[0353] Step 1501: A connection is established between the STA MLD and the source AP MLD.

[0354] The STA MLD is associated with the source AP MLD. The STA MLD and the source AP MLD can transmit signaling, data, and frames.

[0355] Step 1502: disconnect the first source link between the STA MLD and the source AP MLD;

[0356] In the embodiment of the present application, an example is provided in which at least a first source link and a second source link are included between the STA MLD and the source AP MLD, where the first source link is at least one link between the STA MLD and the source AP MLD, and the second source link is at least another link between the STA MLD and the source AP MLD.

[0357] In some embodiments, the STA MLD autonomously disconnects the first source link between the STA MLD and the source AP MLD; or, when the communication quality of the first source link is lower than a first threshold, the STA MLD disconnects the first source link; or, when the communication quality of the first source link is lower than a second threshold, the first source link is automatically disconnected.

[0358] The communication quality may be represented by at least one of an RSSI value, a packet loss rate, a retransmission rate, a number of packet losses, a number of retransmissions, a number of transmission failures, and the like.

[0359] Step 1503: The STA MLD sends first power control trigger information to the source AP MLD;

[0360] The first power control trigger information is used to trigger the source AP MLD to send first power indication information to the candidate AP MLD. The first power indication information is used to adjust or control the transmit power of the candidate AP MLD.

[0361] Adjusting or controlling the transmit power of the candidate AP MLD includes at least one of increasing the transmit power of the candidate AP MLD, decreasing the transmit power of the candidate AP MLD, maintaining the transmit power of the candidate AP MLD, etc. In the embodiment of the present application, the first power indication information is used to increase the transmit power of the candidate AP MLD as an example for schematic description.

[0362] In some embodiments, the STA MLD starts passive scanning of the first target link when executing step 1503; or, the STA MLD starts passive scanning of the first target link after executing step 1503; or, the STA MLD executing step 1503 means that the STA MLD starts passive scanning of the first target link.

[0363] In some embodiments, the STA MLD sends first power control trigger information to the source AP MLD via the second source link.

[0364] In some embodiments, the first power control trigger information is carried in the third frame for transmission.

[0365] Figure 16 shows a schematic diagram of the format of a third frame provided by some exemplary embodiments of the present application. The number below a field indicates the number of bytes or bits in that field. The third frame includes at least one of a Category field, an Action field, a Link ID field, a Dialog Token field, an Element ID field, a Length field, an Element ID extension field, and an AP MLD information field. The length of the AP MLD information field is variable.

[0366] In some embodiments, when the value of the category field is a numerical value D, it indicates that the frame to which the category field belongs is the third frame. Exemplarily, the value range of the numerical value D is [30, 125].

[0367] In some embodiments, the link identification field is used to indicate information of the first target link, such as at least one of the frequency band of the first target link, the link identification of the first target link, and the link index of the first target link.

[0368] In some embodiments, the value of the action field is the first value, indicating that the third frame is used to indicate the first power control trigger information. In this case, the length of the AP MLD information field is 0.

[0369] In some embodiments, the action field takes the second value, indicating that the third frame includes a power upload indication. In this case, the AP MLD information field is used to indicate information of candidate AP MLDs scanned by at least one STA MLD.

[0370] In some embodiments, the AP MLD information field includes an AP MLD address field and a power field. The AP MLD address field is used to indicate the MAC address of the candidate AP MLD scanned by at least one STA MLD, and the power field is used to indicate the target transmit power value adjusted by the candidate AP MLD scanned by at least one STA MLD, that is, the transmit power value that the candidate AP MLD scanned by at least one STA MLD should adopt, that is, the transmit power value of the candidate AP MLD scanned by at least one STA MLD that the STA MLD expects.

[0371] In some embodiments, the unit of the target transmit power value adjusted by the candidate AP MLD scanned by at least one STA MLD is dBm / 20 MHz, and the calculation formula is: P = -20 + F val ′ (6)

[0372] Among them, F val ′ represents the value of the power field, F valThe value range of ′ is [0,60]. Values ​​greater than 60 can be used as reserved values.

[0373] In some embodiments, the action field has a third value, indicating that the third frame includes a target AP MLD confirmation indication. In this case, the AP MLD information field includes information about the target AP MLD. For example, the AP MLD address field included in the AP MLD information field indicates the MAC address of the target AP MLD, and the power field included in the AP MLD information field indicates the transmit power value of the target AP MLD.

[0374] In some embodiments, the action field has the fourth value, indicating that the third frame includes a target AP MLD association completion indication. In this case, the AP MLD information field includes information about the target AP MLD. For example, the AP MLD address field included in the AP MLD information field indicates the MAC address of the target AP MLD; the power field included in the AP MLD information field indicates the transmit power value of the target AP MLD; or the AP MLD information field is a reserved field.

[0375] It should be understood that the frame format shown in FIG16 is merely an example and not limiting. The third frame may also carry fewer or more fields, such as only the category field, action field, and link identifier field; or only the category field, action field, and AP MLD information field; or only the element identifier field, length field, link identifier field, and AP MLD information field; or, in addition to all the fields shown in FIG16 , a reserved field. The order of the fields shown in FIG16 may be adjusted based on actual circumstances, such as the AP MLD information field preceding the link identifier field, the element identifier extension field preceding the length field, the length field following the AP MLD information field, or the AP MLD information field preceding the element identifier field, etc. The number of bytes of the fields shown in FIG16 is variable, such as the power field occupying 2 bytes, the AP MLD information field occupying 8 bytes, the element identifier extension field occupying 0 bytes, etc. The names of the various fields shown in Figure 16 are variable, such as the power field or the transmit power field, the target receive power field, the expected receive power field, the maximum power field, and the link identification field or the target link field, etc.

[0376] Step 1504: The source AP MLD sends first power indication information to the candidate AP MLD;

[0377] The candidate AP MLD is an AP MLD different from the source AP MLD. The candidate AP MLD includes at least one of the following: an AP MLD located on the same physical device as the source AP MLD, an AP MLD located within the signal coverage of the source AP MLD, an AP MLD located within the wireless medium coverage of the source AP MLD, an AP MLD located within the signal coverage of an STA MLD, an AP MLD located within the wireless medium coverage of a STA MLD, and a pre-configured candidate AP MLD.

[0378] In some embodiments, the first power indication information is carried in the fourth frame for transmission.

[0379] Figure 17 shows a schematic diagram of the format of a fourth frame provided by some exemplary embodiments of the present application. The number below a field indicates the number of bytes or bits in that field. The fourth frame includes at least one of a trigger type field, an uplink length field, common information determined by the trigger type field, and a reserved field.

[0380] In some embodiments, the value of the trigger type field is E, indicating that the frame to which the trigger type field belongs is used to indicate power boosting, that is, the fourth frame is used to boost the transmit power of the candidate AP MLD. Exemplary values ​​of E include 8, or 9, 10, 11, or other reserved values.

[0381] In some embodiments, the value of the trigger type field is F, indicating that the frame to which the trigger type field belongs is used to indicate power maintenance, that is, the fourth frame is used to maintain the transmit power of the candidate AP MLD. Exemplary values ​​of F include 9, or 8, 10, 11, or other reserved values.

[0382] In some embodiments, the value of the trigger type field is G, indicating that the frame to which the trigger type field belongs is used to indicate power confirmation, that is, the fourth frame is used to confirm the transmit power of the candidate AP MLD. Exemplary values ​​of G include 10, or 8, 9, 11, or other reserved values.

[0383] In some embodiments, the value of the trigger type field is H, indicating that the frame to which the trigger type field belongs is used to indicate power restoration. That is, the fourth frame is used to restore or recover the transmit power of the candidate AP MLD. Exemplary values ​​for H include 11, or 8, 9, 10, or other reserved values.

[0384] In some embodiments, the common information field determined by the trigger type includes at least one of a link identification field, a power field, and a holding time field.

[0385] In some embodiments, the value of the link identification field is used to indicate the first target link. Exemplarily, the value range of the link identification field is [0, 15]. When the value of the link identification field is 1, it indicates that the link with the link identification of 1 is the first target link. When the value of the link identification field is 12, it indicates that the link with the link identification of 12 is the first target link, and so on. It should be understood that the value range of the link identification field can also be other numerical ranges, such as [1, 16], [0, 10], [2, 18], etc., and each numerical value in the value range can indicate a link one-to-one.

[0386] In some embodiments, the power field is used to instruct the candidate AP MLD to adjust power. The meaning, value or calculation method can refer to the relevant content in the third frame.

[0387] In some embodiments, the hold time field is used to indicate the effective time of the fourth frame, that is, the maintenance time of the power adjustment information indicated by the fourth frame. In some embodiments, the value range of the hold time field is [0, 127], and the unit of the effective time of the fourth frame is milliseconds. It should be understood that the value range of the hold time field can also be other numerical ranges, such as [1, 128], [0, 107], [2, 129], etc., and each value in the value range can correspond to a valid time.

[0388] It should be understood that the frame format shown in FIG17 is merely an example and not limiting. The fourth frame may also carry fewer or more fields, such as carrying only the trigger type field and the common information field determined by the trigger type; or carrying only the trigger type field, the common information field determined by the trigger type, and the reserved field; or carrying only the trigger type field, the link identification field, and the power field; or carrying only the hold time field, the link identification field, the power field, and the reserved field; or carrying a transmit power field in addition to all the fields shown in FIG17 . The order of the fields shown in FIG17 may be adjusted based on actual circumstances, such as the hold time field preceding the link identification field, the power field preceding the link identification field, the common information field determined by the trigger type preceding the reserved field, or the common information field determined by the trigger type preceding the uplink length field, etc. The number of bytes of the fields shown in FIG17 is variable, such as the power field occupying 6 bytes, the hold time field occupying 4 bytes, the link identification field occupying 1 byte, or the reserved field occupying 0 bytes, etc. The names of the various fields shown in Figure 17 are variable, such as the power field or the transmit power field, the target receive power field, the expected receive power field, the maximum power field, the link identification field or the target link field, the hold time field or the valid time field, the effective time field, the timing field, etc.

[0389] Step 1505: The candidate AP MLD adjusts the transmit power;

[0390] The candidate AP MLD increases its own transmit power to a fourth power value based on the received first power indication information.

[0391] In some embodiments, the candidate AP MLD calculates its own maximum transmit power value according to the current network status, that is, calculates the third power value.

[0392] Step 1506: The candidate AP MLD sends the power information of the candidate AP MLD;

[0393] The power information of the candidate AP MLD includes at least one of a fourth power value, a fifth power value, and a third power value, wherein the fifth power value is an expected receive power value of the candidate AP MLD.

[0394] The candidate AP MLD uses the fourth power value to send the power information of the candidate AP MLD.

[0395] In some embodiments, the power information of the candidate AP MLD is carried in the fifth frame.

[0396] Figure 18 shows a schematic diagram of the format of a fifth frame provided by some exemplary embodiments of the present application. The number below a field indicates the number of bytes or bits in that field. The fifth frame includes at least one of an element identification field, a length field, an element identification extension field, a transmit power field, a target receive power field, and a maximum power field.

[0397] In some embodiments, when the value of the element identification field is the value J, and / or the value of the element identification extension field is the value K, it indicates that the frame to which the element identification field and / or the element identification extension field belongs is the fifth frame.

[0398] In some embodiments, the target received power field in the fifth frame is used to indicate the expected received power of the candidate AP MLD, and the calculation formula is referred to the aforementioned formula (1).

[0399] In some embodiments, the maximum power field in the fifth frame is used to indicate the maximum transmit power of the candidate AP MLD.

[0400] In some embodiments, the fifth frame is a beacon frame.

[0401] It should be understood that the frame format shown in FIG18 is merely an example and not limiting. The fifth frame may also carry fewer or more fields, such as carrying only the transmit power field and the target receive power field, or only the transmit power field, the target receive power field, and the maximum power field, or only the element identifier field, the length field, the transmit power field, the target receive power field, and the maximum receive power field, or carrying a reserved field in addition to the six fields shown in FIG18 . The order of the fields shown in FIG18 may be adjusted based on actual circumstances, such as the target receive power field preceding the transmit power field, the element identifier extension field preceding the length field, the length field following the target receive power field, or the maximum power field preceding the transmit power field, etc. The number of bytes of the fields shown in FIG18 is variable, such as the transmit power field occupying 2 bytes, the target receive power field occupying 2 bytes, the maximum power field occupying 0 bytes, the element identifier field occupying 0 bytes, etc. The names of the various fields shown in Figure 18 are variable, such as the transmit power field or the power field, the target receive power field or the expected receive power field, the power field, the maximum power field or the acceptable power threshold field, the acceptable maximum power field, and so on.

[0402] Step 1507: The STA MLD determines a first power value based on the power information of the candidate AP MLD.

[0403] The STA MLD scans the power information of the candidate AP MLD. In other words, the STA MLD scan reaches the fifth frame.

[0404] The first power value is the transmit power value required by the STA MLD when establishing the first target link with the target AP MLD. The second power value is the transmit power value required by the candidate AP MLD when establishing the first target link with the STA MLD.

[0405] In some embodiments, the first power value is calculated by the STA MLD, or is calculated by the source AP MLD and sent to the STA MLD.

[0406] In some embodiments, the power information of the candidate AP MLD includes at least one of a fourth power value, a fifth power value, and a third power value; the STA MLD calculates the first power value and the second power value based on at least one of the fourth power value, the fifth power value, and the third power value.

[0407] In some embodiments, the STA MLD sends the calculated first power value and second power value to the source AP MLD.

[0408] In some embodiments, the STA MLD sends the first power value and the second power value to the source AP MLD on the second source link.

[0409] In some embodiments, the power information of the candidate AP MLD includes at least one of a fourth power value, a fifth power value, and a third power value; the STA MLD sends the power information of the candidate AP MLD, a sixth power value, and a seventh power value to the source AP MLD, where the sixth power value is the expected received power value of the STA MLD on the first target link; and the STA MLD receives the first power value and the second power value sent by the source AP MLD.

[0410] Among them, the third power value is the maximum transmit power value of the candidate AP MLD on the first target link, that is, the third power value is the maximum transmit power value that the candidate AP MLD can use on the first target link while meeting regulatory requirements and based on its own status (for example, power supply status); the fourth power value is the transmit power value adjusted by the candidate AP MLD based on the power control information, that is, the fourth power value is the transmit power value adjusted by the candidate AP MLD on the first target link based on the power control information, that is, the current transmit power of the candidate AP MLD on the first target link; the fifth power value is the target receive power value of the candidate AP MLD on the first target link, that is, the fifth power value is the receive power that the candidate AP MLD expects to be measured when the first target link receives a signal sent by a sender (for example, a STA MLD); the sixth power value is the expected receive power value of the STA MLD on the first target link; and the seventh power value is the receive power value measured when the STA MLD receives a signal sent by the sender (for example, the candidate AP MLD) on the first target link.

[0411] In some embodiments, the STA MLD sends the power information of the candidate AP MLD, the sixth power value, and the seventh power value to the source AP MLD in the second source link.

[0412] Assuming that the first power value is Ps and the second power value is Pa, the calculation formulas for the first power value and the second power value are as follows:

[0413] Where PL represents the path loss, Indicates the expected receive power of the candidate AP MLD when establishing the first target link; Indicates the expected receive power of the STA MLD when establishing the first target link; Indicates the transmit power of the second frame, that is, the transmit power used by the candidate AP MLD to send the second frame; Rx pwr Indicates the receive power of the fifth frame, that is, the receive power corresponding to the fifth frame received by the STA MLD.

[0414] Step 1508: The source AP MLD sends third power indication information to the candidate AP MLD;

[0415] The third power indication information is used to instruct the candidate AP MLD to maintain the transmit power adjusted based on the first power indication information.

[0416] Step 1509: Determine the target AP MLD;

[0417] In some embodiments, a target AP MLD is determined based on the second power value and the third power value.

[0418] In some embodiments, a target AP MLD is determined from the candidate AP MLDs based on a magnitude relationship between the second power value and the third power value.

[0419] Exemplarily, when the second power value is less than or equal to the third power value, that is, Pa≤Pmax, the candidate AP MLD corresponding to the third power value greater than or equal to the second power value is the target AP MLD, and the STA MLD can establish a first target link with the target AP MLD.

[0420] In some embodiments, a target AP MLD is determined from the candidate AP MLDs based on the priority scores. The target AP MLD is the AP MLD with the highest priority score among the candidate AP MLDs. The priority score is determined based on the power information of the candidate AP MLD and the second power value.

[0421] In some embodiments, the priority score is the difference between a first product and a second sum. The first product is the product of the third power value corresponding to the candidate AP MLD and the first weight, the second sum is the sum of the second product and the third product, the second product is the product of the path loss and the second weight, and the third product is the product of the second power value and the third weight. The sum of the first, second, and third weights is 1 or 100%.

[0422] Assuming that the first weight is α, the second weight is β, the third weight is γ, the third power value is Pmax, the path loss is PL, and the second power value is Pa, then the priority score Score is calculated as follows: Score = α·Pmax-β·PL-γ·Pa (5)

[0423] Here, α+β+γ=1, or α+β+γ=100%. Moreover, the value of α belongs to [0,1], the value of β belongs to [0,1], and the value of γ belongs to [0,1].

[0424] In some embodiments, the target AP MLD is determined by the STA MLD and sent to the source AP MLD; or, the target AP MLD is determined by the source AP MLD and sent to the STA MLD; or, the target AP MLD is determined by both the STA MLD and the source AP MLD. In other words, the relationship between the second power value and the third power value can be determined by the source AP MLD, the STA MLD, or both the source AP MLD and the STA MLD; and the priority score can be calculated based on the source AP MLD, the STA MLD, or both the source AP MLD and the STA MLD.

[0425] In some embodiments, the priority score is calculated by the STA MLD, that is, the target AP MLD is determined by the STA MLD, and the STA MLD sends a target AP MLD confirmation indication to the source AP MLD to inform the source AP MLD of the target AP MLD. In some embodiments, the target AP MLD confirmation indication also includes a second power value corresponding to the target AP MLD.

[0426] In some embodiments, the priority score is calculated by the source AP MLD, that is, the target AP MLD is determined by the source AP MLD. The source AP MLD sends a target AP MLD confirmation indication to the STA MLD to inform the STA MLD of the target AP MLD. In some embodiments, the target AP MLD confirmation indication also includes a fourth power value corresponding to the target AP MLD.

[0427] Step 1510: The STA MLD sends power confirmation indication information to the source AP MLD;

[0428] The power confirmation indication information is used to instruct the target AP MLD to set the transmit power to the second power value.

[0429] In some embodiments, the STA MLD sends a power confirmation indication to the source AP MLD over the second source link.

[0430] Step 1511: The source AP MLD sends power confirmation indication information to the target AP MLD;

[0431] In some embodiments, the target AP MLD maintains the second power value as the transmit power until receiving second power indication information from the source AP MLD. The second power indication information is used to restore the transmit power of the candidate AP MLD, that is, to restore the transmit power of the candidate AP MLD from the fourth power value to the transmit power value before receiving the first power indication information.

[0432] In some embodiments, the first power indication information indicates a holding time, that is, the validity time of the first power indication information. After the holding time expires, the candidate AP MLD automatically restores the transmit power.

[0433] In some embodiments, the power confirmation indication information indicates a holding time, that is, the effective time of the power confirmation indication. After the holding time expires, the candidate AP MLD automatically restores the transmit power.

[0434] The candidate AP MLD restores transmit power, which can reduce power consumption and mitigate the negative impact of link switching on the communication system, such as signal interference.

[0435] Step 1512: Establish a first target link;

[0436] A first target link is established between the STA MLD and the target AP MLD based on the first power value and the second power value.

[0437] Illustratively, step 1512 includes step 1512a, step 1512b, step 1512c, and step 1512d.

[0438] Step 1512a: STA MLD sends an authentication request;

[0439] In some embodiments, the STA MLD sends an authentication request to the source AP MLD, and the source AP MLD sends an authentication request to the target AP MLD; or, the STA MLD sends an authentication request to the target AP MLD.

[0440] In some embodiments, the STA MLD sends an authentication request to the target AP MLD using a first power value.

[0441] Step 1512b: The target AP MLD sends an authentication response.

[0442] In some embodiments, the target AP MLD sends an authentication response to the source AP MLD, and the source AP MLD sends an authentication response to the STA MLD; or, the target AP MLD sends an authentication response to the STA MLD.

[0443] In some embodiments, the target AP MLD sends an authentication response to the STA MLD using a second power value.

[0444] Step 1512c: The STA MLD sends a reassociation request to the target AP MLD.

[0445] In some embodiments, the STA MLD sends a reassociation request to the target AP MLD using a first power value.

[0446] Step 1512d: The target AP MLD sends a reassociation response to the STA MLD.

[0447] In some embodiments, the target AP MLD sends a reassociation response to the STA MLD using a second power value.

[0448] For details about authentication requests, authentication responses, reassociation requests, and reassociation responses, refer to the relevant contents in the IEEE 802.11r protocol.

[0449] Step 1513: The STA MLD sends an association success indication to the source AP MLD;

[0450] The association success indication is used to indicate to the source AP MLD that the first target link is successfully established, that is, the association between the STA MLD and the target AP MLD is successful.

[0451] In some embodiments, the association success indication is further used to trigger the source AP MLD to send second power indication information. The second power indication information is used to restore the transmit power of the candidate AP MLD, that is, to restore the transmit power of the candidate AP MLD from the fourth power value to the transmit power value before receiving the first power indication information.

[0452] Step 1514: Establish a second target link based on the first target link.

[0453] In some embodiments, the STA MLD autonomously disconnects the second source link between the STA MLD and the source AP MLD; or, when the communication quality of the second source link is lower than a third threshold, the STA MLD disconnects the second source link; or, when the communication quality of the second source link is lower than a fourth threshold, the second source link is automatically disconnected.

[0454] In some embodiments, the STA MLD sends a disassociation indication to the source AP MLD, where the disassociation indication is used to disassociate the STA MLD from the source AP MLD and / or disconnect the second source link.

[0455] In some embodiments, with the assistance of the first target link, the STA MLD establishes a second target link with the target AP MLD.

[0456] In some embodiments, the STA MLD establishes a second target link with the target AP MLD using the FT technology. For example, the STA MLD sends an authentication request to the target AP MLD on the first target link, the target AP MLD sends an authentication response to the STA MLD on the first target link, the STA MLD sends a reassociation request to the target AP MLD on the first target link, and the target AP MLD sends a reassociation response to the STA MLD on the first target link, thereby completing the establishment of the second target link, i.e., completing the handover from the second source link to the second target link.

[0457] It should be understood that in the embodiments of the present application, steps 1508, 1510, 1511, 1513, and 1514 are optional steps. Steps 1503 and 1504 can be combined into one step, and steps 1510 and 1511 can be combined into one step. Step 1513 can be split into two steps: the STA MLD sends an association success indication, and the source AP MLD sends a second power indication. The execution order of each step can be adaptively adjusted based on the specific situation. For example, step 1514 can precede step 1513, step 1508 can follow step 1509, and so on.

[0458] In some embodiments, steps 1504 to 1506 are repeated before step 1507 is performed, or steps 1504 to 1508 are repeated before step 1509 is performed. That is, before determining the target AP MLD, the STA MLD may scan the power information of the candidate AP MLDs in real time and calculate the first power value multiple times until the target AP MLD is determined.

[0459] It should be understood that some or all of the steps in the link switching method shown in FIG15 may also be performed by the target AP MLD, which is a candidate AP MLD. For example, the target AP MLD may perform steps 1505, 1506, 1512, 1514, and 1511, and may also participate in steps 1507, 1508, and so on.

[0460] In summary, the method provided by the embodiment of the present application supports STA MLD to control the transmission power of the candidate AP MLD by sending power control information during the link switching process, determines the target AP MLD in the candidate AP MLD by passive scanning, and establishes a first target link by controlling the transmission power of the target AP MLD and the transmission power of the STA MLD. The first target link established on this basis has high reliability. Moreover, during the period of switching the first source link to the first target link, maintaining the connection between the STA MLD and the source AP MLD can avoid the problem of data transmission interruption during the link switching process, reduce the possibility of users perceiving data transmission interruption, and improve user experience. In addition, STA MLD can also establish a second target link based on the established first target link, so that roaming from the source AP MLD to the target AP MLD has high reliability and high simplicity, greatly improving the efficiency and stability of the communication system and ensuring the communication quality.

[0461] It should be understood that the formats, names, and values ​​of the frames / elements / fields involved in the various embodiments of the present application are merely examples and are not intended to limit the formats, names, and values ​​of the frames / elements / fields. In different embodiments or designs, at least one of the names of the aforementioned elements / fields, their positions in the frame, their order with other elements / fields, the number of bytes occupied, or the number of bits occupied may be changed.

[0462] Figure 19 illustrates the relationship between communication quality and link handover, as provided in some exemplary embodiments of the present application. Taking RSSI values ​​as an example, as shown in Figure 19, if the RSSI value of the first source link is below threshold T1, the transmit power of the candidate AP MLD can be increased. In other words, the RSSI value of the first target link corresponding to the target AP MLD is also increased.

[0463] Once the target AP MLD is determined, or when the RSSI value of the first target link corresponding to the target AP MLD reaches threshold T2, the first target link can be established. This means that the first target link is established and highly reliable. At this point, the STA MLD remains associated with both the source AP MLD and the target AP MLD, maintaining the link connection.

[0464] When the RSSI value of the second source link is lower than the threshold T3, the second source link to the second target link can be switched, the STA MLD can disassociate with the source AP MLD and disconnect the second source link. Afterwards, the STA MLD can establish a second target link with the target AP MLD.

[0465] Considering that a STA's simultaneous association with both the source and target AP MLDs is only a transient state during roaming, to reduce the time a STA maintains association with both AP MLDs, thereby reducing resource and power waste while ensuring the communication quality of the second target link, you can set threshold T3 to be greater than T1.

[0466] Among them, the first target link baseline represents the RSSI value of the first target link when the link switching method provided in the embodiment of the present application is not adopted, that is, the RSSI value of the first target link established without adjusting the transmission power of the target AP MLD through power control information.

[0467] Figure 20 shows a block diagram of a link switching device provided by some exemplary embodiments of the present application. The device includes at least some of the following modules: a first sending module 2010, a first processing module 2030, and a first receiving module 2050:

[0468] A first sending module 2010 is configured to send power control information during the process of switching the first source link to the first target link;

[0469] The power control information is used to control the transmission power of the candidate AP MLD or the target AP MLD, the first source link is at least one link corresponding to the STA MLD and the source AP MLD, the first target link is at least one link corresponding to the STA MLD and the target AP MLD, and the target AP MLD is one of the candidate AP MLDs.

[0470] In some embodiments, the first sending module 2010 is further configured to execute the sending steps executed by the STA MLD in the above-mentioned various method embodiments.

[0471] The first processing module 2030 is configured to execute the determination-related steps, the processing-related steps, and the calculation-related steps executed by the STA MLD in each of the above method embodiments.

[0472] The first receiving module 2050 is configured to execute the receiving steps performed by the STA MLD in each of the above method embodiments.

[0473] In some embodiments, the apparatus provided by the embodiments of the present application includes a first sending module 2010, and the first sending module 2010 supports executing all the sending steps performed by the STA MLD in the above-mentioned various method embodiments.

[0474] In some embodiments, the apparatus provided by the embodiments of the present application includes multiple first sending modules 2010, and the multiple first sending modules 2010 respectively support executing part of the sending steps performed by the STA MLD in each of the above method embodiments.

[0475] In some embodiments, the steps performed by different first sending modules 2010 are completely the same, partially the same, or completely different.

[0476] In some embodiments, the apparatus provided by the embodiments of the present application includes a first processing module 2030, which supports the execution of all determination-related steps, processing-related steps, and calculation-related steps performed by the STA MLD in the above-mentioned various method embodiments.

[0477] In some embodiments, the device provided by the embodiments of the present application includes multiple first processing modules 2030, which respectively support the execution of some of the determination-related steps and / or processing-related steps and / or calculation-related steps performed by STA MLD in the above-mentioned method embodiments.

[0478] In some embodiments, the steps performed by different first processing modules 2030 are completely the same, partially the same, or completely different.

[0479] In some embodiments, the apparatus provided by the embodiments of the present application includes a first receiving module 2050 , which supports executing all the receiving steps performed by the STA MLD in the above-mentioned various method embodiments.

[0480] In some embodiments, the apparatus provided by the embodiments of the present application includes multiple first receiving modules 2050 , and the multiple first receiving modules 2050 respectively support executing part of the receiving steps performed by the STA MLD in each of the above method embodiments.

[0481] In some embodiments, the steps performed by different first receiving modules 2050 are completely the same, partially the same, or completely different.

[0482] In summary, the apparatus provided in this application supports controlling the transmit power of a candidate AP MLD by sending power control information during a link switching process to achieve active or passive scanning of the first target link. The link switching method is highly flexible, and the first target link established on this basis is also highly reliable. Furthermore, data transmission interruptions during the link switching process can be avoided, reducing the likelihood of users perceiving data transmission interruptions and improving the user experience. Furthermore, a second target link can be established based on the established first target link, making roaming from the source AP MLD to the target AP MLD highly reliable and simple.

[0483] Figure 21 shows a block diagram of a link switching device provided by some exemplary embodiments of the present application. The device includes at least some of the following modules: a second receiving module 2110, a second processing module 2130, and a second sending module 2150:

[0484] The second receiving module 2110 is configured to receive power control information during the process of switching the first source link to the first target link;

[0485] The power control information is used to control the transmission power of the candidate AP MLD or the target AP MLD, the first source link is at least one link corresponding to the STA MLD and the source AP MLD, the first target link is at least one link corresponding to the STA MLD and the target AP MLD, and the target AP MLD is one of the candidate AP MLDs.

[0486] In some embodiments, the second receiving module 2110 is further configured to execute the receiving step performed by the candidate AP MLD in each of the above method embodiments.

[0487] The second processing module 2130 is configured to execute the determination-related steps, processing-related steps, and calculation-related steps executed by the candidate AP MLD in each of the above method embodiments.

[0488] The second sending module 2150 is configured to execute the sending steps performed by the candidate AP MLD in each of the above method embodiments.

[0489] In some embodiments, the apparatus provided by the embodiments of the present application includes a second receiving module 2110 , which supports executing all the receiving steps performed by the candidate AP MLD in the above-mentioned various method embodiments.

[0490] In some embodiments, the apparatus provided by the embodiments of the present application includes multiple second receiving modules 2110 , which respectively support executing part of the receiving steps performed by the candidate AP MLD in each of the above method embodiments.

[0491] In some embodiments, the steps performed by different second receiving modules 2110 are completely the same, partially the same, or completely different.

[0492] In some embodiments, the apparatus provided by the embodiments of the present application includes a second processing module 2130, which supports the execution of all determination-related steps, processing-related steps, and calculation-related steps performed by the candidate AP MLD in the above-mentioned various method embodiments.

[0493] In some embodiments, the apparatus provided by the embodiments of the present application includes multiple second processing modules 2130, which respectively support the execution of some of the determination-related steps and / or processing-related steps and / or calculation-related steps performed by the candidate AP MLD in the above-mentioned various method embodiments.

[0494] In some embodiments, the steps performed by different second processing modules 2130 are completely the same, partially the same, or completely different.

[0495] In some embodiments, the apparatus provided by the embodiments of the present application includes a second sending module 2150 , which supports executing all the sending steps performed by the candidate AP MLD in the above-mentioned various method embodiments.

[0496] In some embodiments, the apparatus provided by the embodiments of the present application includes multiple second sending modules 2150, and the multiple second sending modules 2150 respectively support executing part of the sending steps performed by the candidate AP MLD in each of the above method embodiments.

[0497] In some embodiments, the steps performed by different second sending modules 2150 are completely the same, partially the same, or completely different.

[0498] In summary, the apparatus provided in this application supports adjusting transmit power based on power control information during link switching, and supports STA MLDs establishing connections with target AP MLDs through active or passive scanning. This link switching method offers high flexibility and improves the reliability of the first target link between the STA MLD and the target AP MLD. Furthermore, the link switching method can avoid data transmission interruptions during link switching, reducing the likelihood of users perceiving data transmission interruptions and improving the user experience.

[0499] Figure 22 shows a block diagram of a link switching device provided by some exemplary embodiments of the present application. The device includes at least some of the following modules: a transmission module 2210, a third processing module 2230, a third receiving module 2212, and a third sending module 2214:

[0500] The transmission module 2210 is configured to transmit power control information during the process of switching the first source link to the first target link;

[0501] The power control information is used to control the transmission power of the candidate AP MLD or the target AP MLD, the first source link is at least one link corresponding to the STA MLD and the source AP MLD, the first target link is at least one link corresponding to the STA MLD and the target AP MLD, and the target AP MLD is one of the candidate AP MLDs.

[0502] The third processing module 2230 is configured to execute the determination-related steps, processing-related steps, and calculation-related steps executed by the source AP MLD in each of the above method embodiments.

[0503] In some embodiments, the transmission module 2210 includes a third receiving module 2212 , which is configured to execute the receiving steps executed by the source AP MLD in each of the above method embodiments.

[0504] In some embodiments, the transmission module 2210 includes a third sending module 2214, which is configured to execute the sending steps executed by the source AP MLD in each of the above method embodiments.

[0505] In some embodiments, the apparatus provided by the embodiments of the present application includes a transmission module 2210 , which supports executing all transmission steps performed by the source AP MLD in the above-mentioned various method embodiments.

[0506] In some embodiments, the apparatus provided by the embodiments of the present application includes multiple transmission modules 2210 , which respectively support executing part of the transmission steps performed by the source AP MLD in each of the above method embodiments.

[0507] In some embodiments, the steps performed by different transmission modules 2210 are exactly the same, partially the same, or completely different.

[0508] In some embodiments, the apparatus provided by the embodiments of the present application includes a third processing module 2230, which supports executing all determination-related steps, processing-related steps, and calculation-related steps performed by the source AP MLD in the above-mentioned various method embodiments.

[0509] In some embodiments, the apparatus provided by the embodiments of the present application includes multiple third processing modules 2230, which respectively support the execution of some of the determination-related steps and / or processing-related steps and / or calculation-related steps performed by the source AP MLD in the above-mentioned various method embodiments.

[0510] In some embodiments, the steps performed by different third processing modules 2230 are identical, partially identical, or completely different.

[0511] In some embodiments, the apparatus provided by the embodiments of the present application includes a third sending module 2214, which supports executing all the sending steps performed by the source AP MLD in the above-mentioned various method embodiments.

[0512] In some embodiments, the apparatus provided by the embodiments of the present application includes a third receiving module 2212 , which supports executing all the receiving steps performed by the source AP MLD in the above-mentioned various method embodiments.

[0513] In some embodiments, the apparatus provided by the embodiments of the present application includes multiple third receiving modules 2212 , which respectively support executing part of the receiving steps performed by the source AP MLD in each of the above method embodiments.

[0514] In some embodiments, the steps performed by different third receiving modules 2212 are completely the same, partially the same, or completely different.

[0515] In some embodiments, the apparatus provided by the embodiments of the present application includes multiple third sending modules 2214, and the multiple third sending modules 2214 respectively support executing part of the sending steps performed by the source AP MLD in each of the above method embodiments.

[0516] In some embodiments, the steps performed by different third sending modules 2214 are completely the same, partially the same, or completely different.

[0517] In summary, the apparatus provided herein supports controlling the transmit power of a candidate AP MLD by transmitting power control information during a link switching process, thereby ensuring a highly reliable first target link between the STA MLD and the target AP MLD. Furthermore, the link switching method can avoid data transmission interruptions during the link switching process, reducing the likelihood of user-perceived data transmission interruptions and improving the user experience.

[0518] It should be noted that the device provided in the above embodiment is only illustrated by the division of the above functional modules. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0519] Regarding the device in this embodiment, the specific manner in which each module performs operations has been described in detail in the embodiment of the method and will not be elaborated here.

[0520] Figure 23 shows a schematic structural diagram of a wireless communication device (AP or STA) provided in some exemplary embodiments of the present application. The wireless communication device 2300 includes: a processor 2301, a receiver 2302, a transmitter 2303, a memory 2304 and a bus 2305.

[0521] The processor 2301 includes one or more processing cores. The processor 2301 executes various functional applications and information processing by running software programs and modules. In some embodiments, the processor 2301 can be used to implement the functions and steps of the first processing module 2030 and / or the second processing module 2130 and / or the third processing module 2230 described above.

[0522] The receiver 2302 and transmitter 2303 can be implemented as a communication component, which can be a communication chip. In some embodiments, the receiver 2302 can be used to implement the functions and steps of the first receiving module 2050 and / or the second receiving module 2110 and / or the third receiving module 2212 described above. In some embodiments, the transmitter 2303 can be used to implement the functions and steps of the first transmitting module 2010 and / or the second transmitting module 2150 and / or the third transmitting module 2214 described above.

[0523] The memory 2304 is connected to the processor 2301 via a bus 2305. The memory 2304 may be used to store at least one instruction, and the processor 2301 may be used to execute the at least one instruction to implement each step in the above method embodiment.

[0524] In addition, the memory 2304 can be implemented by any type of volatile or non-volatile storage device or a combination thereof. Volatile or non-volatile storage devices include but are not limited to: magnetic disks or optical disks, Electrically Erasable Programmable Read Only Memory (EEPROM), Erasable Programmable Read-Only Memory (EPROM), Static Random-Access Memory (SRAM), Read-Only Memory (ROM), magnetic memory, flash memory, and Programmable Read-Only Memory (PROM).

[0525] In some embodiments, the receiver 2302 receives signals / data independently, or the processor 2301 controls the receiver 2302 to receive signals / data, or the processor 2301 requests the receiver 2302 to receive signals / data, or the processor 2301 cooperates with the receiver 2302 to receive signals / data.

[0526] In some embodiments, the transmitter 2303 independently sends signals / data, or the processor 2301 controls the transmitter 2303 to send signals / data, or the processor 2301 requests the transmitter 2303 to send signals / data, or the processor 2301 cooperates with the transmitter 2303 to send signals / data.

[0527] In an exemplary embodiment of the present application, a computer-readable storage medium is also provided, in which at least one program is stored. The at least one program is loaded and executed by a processor, and the computer-readable storage medium is used to implement the link switching method provided by the above-mentioned various method embodiments.

[0528] In an exemplary embodiment of the present application, a chip is further provided, which includes a programmable logic circuit and / or program instructions. When the chip runs on a communication device, it is used to implement the link switching method provided by the above-mentioned various method embodiments.

[0529] In an exemplary embodiment of the present application, a computer program product is further provided. When the computer program product is executed on a processor of a computer device, the computer device is enabled to execute the above-mentioned link switching method.

[0530] In an exemplary embodiment of the present application, a computer program is further provided. The computer program includes computer instructions. A processor of a computer device executes the computer instructions, so that the computer device executes the above-mentioned link switching method.

[0531] Those skilled in the art will appreciate that in one or more of the above examples, the functions described in the embodiments of the present application can be implemented using hardware, software, firmware, or any combination thereof. When implemented using software, these functions can be stored in a computer-readable medium or transmitted as one or more instructions or codes on a computer-readable medium. Computer-readable media include computer storage media and communication media, wherein communication media include any media that facilitates the transmission of computer programs from one place to another. The storage medium can be any available medium that can be accessed by a general-purpose or special-purpose computer.

[0532] It should be understood that the frame format and element format shown in the embodiments of the present application are exemplary cases. In different embodiments or different designs, it is not ruled out that at least one of the positions of the fields in the frame / element, the arrangement order with other fields, the number of bytes occupied, and the number of bits occupied may be changed. The present application does not limit the specific format of each frame or each element.

[0533] The above description is merely an optional embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A link switching method, characterized in that: The method is performed by a STA MLD, and the method includes: In a process of switching the first source link to the first target link, sending power control information; The power control information is used to control the transmission power of the candidate AP MLD or the target AP MLD, the first source link is at least one link corresponding to the STA MLD and the source AP MLD, the first target link is at least one link corresponding to the STA MLD and the target AP MLD, and the target AP MLD is one of the candidate AP MLDs.

2. The method according to claim 1, characterized in that The power control information includes first power indication information; The transmission power control information includes: The first power indication information is sent to the candidate AP MLD.

3. The method according to claim 1, characterized in that The power control information includes first power control trigger information; The transmission power control information includes: The first power control trigger information is sent to the source AP MLD, where the first power control trigger information is used to trigger the source AP MLD to send first power indication information to the candidate AP MLD, where the first power indication information is used to adjust the transmit power of the candidate AP MLD.

4. The method according to any one of claims 1 to 3, characterized in that: The method further comprises: Receive power information of the candidate AP MLD.

5. The method according to any one of claims 1 to 4, characterized in that: The method further comprises: Based on the power information of the candidate AP MLD, a first power value is determined, where the first power value is a transmit power value required for the STA MLD to establish the first target link.

6. The method according to any one of claims 1 to 5, characterized in that: The method further comprises: Based on the power information of the candidate AP MLD, a second power value is determined, where the second power value is a transmission power value required for the candidate AP MLD to establish a link with the STA MLD.

7. The method according to claim 6, characterized in that The method further comprises: The first power value and the second power value are sent to the source AP MLD.

8. The method according to any one of claims 1 to 7, characterized in that: The target AP MLD is an AP MLD with the highest priority score among the candidate AP MLDs; The priority score is determined based on the power information of the candidate AP MLD and a first power value, where the first power value is a transmission power value required for the STA MLD to establish the first target link.

9. The method according to claim 8, characterized in that The power information of the candidate AP MLD includes a third power value, where the third power value is a maximum transmit power value of the candidate AP MLD; The priority score is determined based on the third power value, path loss, and the first power value of the candidate AP MLD.

10. The method according to any one of claims 1 to 9, characterized in that: The power control information includes second power indication information; The transmission power control information includes: Sending the second power indication information to other candidate AP MLDs; The other candidate AP MLDs are AP MLDs other than the target AP MLD among the candidate AP MLDs, and the second power indication information is used to restore the transmit power of the other candidate AP MLDs.

11. The method according to any one of claims 1 to 9, characterized in that: The power control information includes second power control trigger information; The transmission power control information includes: Sending the second power control trigger information to the source AP MLD, where the second power control trigger information is used to trigger the source AP MLD to send second power indication information to other candidate AP MLDs; The other candidate AP MLDs are AP MLDs other than the target AP MLD among the candidate AP MLDs, and the second power indication information is used to restore the transmit power of the other candidate AP MLDs.

12. The method according to claim 2, characterized in that: The first power indication information is carried in a first frame for transmission; The first frame includes at least one of a transmit power field and a target receive power field.

13. The method according to any one of claims 5 to 9, characterized in that: The power information of the candidate AP MLD is carried in the second frame for transmission; The second frame includes at least one of a transmit power field, a target receive power field, and a maximum power field.

14. The method according to claim 3, characterized in that The first power control trigger information is transmitted on a second source link, where the second source link is at least one link corresponding to the STA MLD and the source AP MLD except the first source link.

15. The method according to claim 3 or 14, characterized in that The first power control trigger information is carried in a third frame for transmission; The third frame includes at least one of a category field, an action field, a link identification field, a dialog token field, an element identification field, a length field, an element identification extension field, an AP MLD information field, and the like.

16. The method according to claim 15, characterized in that The AP MLD information field includes at least one of an AP MLD address field and a power field.

17. The method according to claim 15 or 16, characterized in that The value of the action field includes at least one of the following: A first value indicates that the second frame is used to indicate the first power control trigger information; The second value indicates that the second frame includes a power upload indication; The third value indicates that the second frame includes a target AP MLD confirmation indication; The fourth value indicates that the second frame includes a target AP MLD association completion indication.

18. The method according to any one of claims 3 or 14 to 17, characterized in that: The first power indication information is carried in a fourth frame for transmission; The fourth frame includes at least one of a link identification field, a power field, and a Life Time field.

19. A link switching method, characterized in that: The method is performed by a target AP MLD, and the method includes: receiving power control information during switching the first source link to the first target link; The power control information is used to control the transmission power of the candidate AP MLD or the target AP MLD, the first source link is at least one link corresponding to the STA MLD and the source AP MLD, the first target link is at least one link corresponding to the STA MLD and the target AP MLD, and the target AP MLD is one of the candidate AP MLDs.

20. The method according to claim 19, characterized in that The receiving power control information includes: The first power indication information sent by the STA MLD is received, where the first power indication information is used to adjust the transmit power of the candidate AP MLD.

21. The method according to claim 20, characterized in that The receiving power control information includes: The first power indication information sent by the source AP MLD is received, where the first power indication information is used to adjust the transmit power of the candidate AP MLD.

22. The method according to any one of claims 19 to 21, characterized in that: The method further comprises: The power information of the target AP MLD is sent to the STA MLD.

23. The method according to any one of claims 19 to 22, characterized in that: The target AP MLD is an AP MLD with the highest priority score among the candidate AP MLDs; The priority score is determined based on the power information of the target AP MLD and a first power value, where the first power value is a transmission power value required for the STA MLD to establish the first target link.

24. The method according to claim 23, characterized in that The power information of the target AP MLD includes a third power value, where the third power value is a maximum transmit power value of the target AP MLD; The priority score of the target AP MLD is determined based on the third power value, path loss, and the first power value of the target AP MLD.

25. The method according to claim 20, characterized in that The first power indication information is carried in a first frame for transmission; The first frame includes at least one of a transmit power field and a target receive power field.

26. The method according to claim 22, characterized in that The power information of the target AP MLD is carried in the second frame for transmission; The second frame includes at least one of a transmit power field, a target receive power field, and a maximum power field.

27. The method according to claim 21, characterized in that The first power indication information is carried in a fourth frame for transmission; The fourth frame includes at least one of a link identification field, a power field, and a Life Time field.

28. A link switching method, characterized in that: The method is performed by a source AP MLD, and the method includes: transmitting power control information during the process of switching the first source link to the first target link; The power control information is used to control the transmission power of the candidate AP MLD or the target AP MLD, the first source link is at least one link corresponding to the STA MLD and the source AP MLD, the first target link is at least one link corresponding to the STA MLD and the target AP MLD, and the target AP MLD is one of the candidate AP MLDs.

29. The method according to claim 28, characterized in that The transmission power control information includes: receiving first power control trigger information sent by the STA MLD, where the first power control trigger information is used to trigger the source AP MLD to send first power indication information to the candidate AP MLD; Sending the first power indication information to the candidate AP MLD; The first power indication information is used to adjust the transmit power of the candidate AP MLD.

30. The method according to claim 28 or 29, characterized in that The method further comprises: Receiving a first power value and a second power value sent by the STA MLD; The first power value is the transmit power value required by the STA MLD to establish the first target link, and the second power value is The transmit power value required for the candidate AP MLD to establish a link with the STA MLD.

31. The method according to claim 30, characterized in that The method further comprises: Sending third power indication information to the candidate AP MLD, where the third power indication information is used to instruct the candidate AP MLD to maintain the transmit power adjusted based on the first power indication information.

32. The method according to any one of claims 28 to 31, characterized in that The target AP MLD is an AP MLD with the highest priority score among the candidate AP MLDs; The priority score is determined based on the power information of the candidate AP MLD and a first power value, where the first power value is a transmission power value required for the STA MLD to establish the first target link.

33. The method according to claim 32, characterized in that The power information of the candidate AP MLD includes a third power value, where the third power value is a maximum transmit power value of the candidate AP MLD; The priority score is determined based on the third power value, path loss, and the first power value of the candidate AP MLD.

34. The method according to any one of claims 28 to 33, characterized in that The power control information includes second power indication information; The transmission power control information includes: Sending the second power indication information to other candidate AP MLDs; The other candidate AP MLDs are AP MLDs other than the target AP MLD among the candidate AP MLDs, and the second power indication information is used to restore the transmit power of the other candidate AP MLDs.

35. The method according to claim 34, characterized in that Before sending the second power indication information to other candidate AP MLDs, the method further includes: The second power control trigger information sent by the STA MLD is received, where the second power control trigger information is used to trigger the source AP MLD to send the second power indication information to other candidate AP MLDs.

36. The method according to claim 29, characterized in that The first power control trigger information is carried in a third frame for transmission; The third frame includes at least one of a category field, an action field, a link identification field, a dialog token field, an element identification field, a length field, an element identification extension field, an AP MLD information field, and the like.

37. The method according to claim 33, characterized in that The AP MLD information field includes at least one of an AP MLD address field and a power field.

38. The method according to claim 36 or 37, characterized in that The value of the action field includes at least one of the following: A first value indicates that the second frame is used to indicate the first power control trigger information; The second value indicates that the second frame includes a power upload indication; The third value indicates that the second frame includes a target AP MLD confirmation indication; The fourth value indicates that the second frame includes a target AP MLD association completion indication.

39. The method according to any one of claims 24 or 36 to 38, characterized in that: The first power indication information is carried in a fourth frame for transmission; The fourth frame includes at least one of a link identification field, a power field, and a Life Time field.

40. A link switching device, characterized in that: The device comprises: A first sending module, configured to send power control information during a process of switching the first source link to the first target link; Among them, the power control information is used to control the transmission power of the candidate AP MLD or the target AP MLD, the first source link is at least one link corresponding to the device and the source AP MLD, the first target link is at least one link corresponding to the device and the target AP MLD, and the target AP MLD is one of the candidate AP MLDs.

41. A link switching device, characterized in that: The device comprises: A second receiving module, configured to receive power control information during the process of switching the first source link to the first target link; The power control information is used to control the transmission power of the candidate AP MLD or the device, the first source link is at least one link corresponding to the STA MLD and the source AP MLD, the first target link is at least one link corresponding to the STA MLD and the device, and the device is one of the AP MLDs among the candidate AP MLDs.

42. A link switching device, characterized in that: The device comprises: A transmission module, configured to transmit power control information during the process of switching the first source link to the first target link; Among them, the power control information is used to control the transmission power of the candidate AP MLD or the target AP MLD, the first source link is at least one link corresponding to the STA MLD and the device, the first target link is at least one link corresponding to the STA MLD and the target AP MLD, and the target AP MLD is one of the candidate AP MLDs.

43. A wireless device, characterized in that: The wireless device comprises: processor; a transceiver connected to the processor; a memory for storing executable instructions for the processor; The processor is configured to load and execute the executable instructions to implement the link switching method as described in any one of claims 1 to 18, or the link switching method as described in any one of claims 19 to 27, or the link switching method as described in any one of claims 28 to 39.

44. A computer-readable storage medium, characterized in that The readable storage medium stores executable instructions, which are loaded and executed by a processor to implement the link switching method as described in any one of claims 1 to 18, or the link switching method as described in any one of claims 19 to 27, or the link switching method as described in any one of claims 28 to 39.

45. A chip, characterized in that: The chip includes a programmable logic circuit or a program, and the chip is used to implement the link switching method as described in any one of claims 1 to 18, or the link switching method as described in any one of claims 19 to 27, or the link switching method as described in any one of claims 28 to 39.

46. ​​A computer program product, characterized in that The computer program product includes computer instructions, which are stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions, so that the computer device executes the link switching method as described in any one of claims 1 to 18, or the link switching method as described in any one of claims 19 to 27, or the link switching method as described in any one of claims 28 to 39.

47. A computer program, characterized in that The computer program includes computer instructions, and the processor of the computer device executes the computer instructions, so that the computer device performs the link switching method as described in any one of claims 1 to 18, or the link switching method as described in any one of claims 19 to 27, or the link switching method as described in any one of claims 28 to 39.

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