Data transmission method, system and device in roaming handover process and storage medium

Abstract

The application discloses a data transmission method, system and device in a roaming switching process and a storage medium, relates to the technical field of wireless communication, and discloses a data transmission method in a roaming switching process, which is applied to a first access point device and comprises the following steps: obtaining first downlink data to be sent to a non-access point device; wherein the first access point device is an access point device to which the non-access point device is switched from a second access point device during roaming switching; after receiving second information, the first downlink data is sent to the non-access point device; wherein the second information is used for notifying the first access point device that second downlink data on the second access point device has been sent to the non-access point device, and allowing the first access point device to send the first downlink data to the non-access point device. The application realizes the data sequence preserving transmission of the non-access point device in the roaming switching process, that is, the downlink data of the second access point device is received first and then the downlink data of the first access point device is received.

Description

Technical Field

[0001] This application relates to the field of wireless communication technology, and in particular to data transmission methods, systems, devices and storage media during roaming handover. Background Technology

[0002] With the rapid development of wireless network technology, users have placed higher demands on the coverage and connection quality of wireless networks. Especially during roaming handover, when a user equipment (station: STA) is within the coverage area of ​​multiple wireless access points (APs), it can exchange data with network-side devices through one AP to establish a network connection. When moving from the coverage area of ​​one AP to the coverage area of ​​another AP, it is necessary to switch from the currently serving AP (also known as the current AP) to an AP with a stronger signal (also known as the target AP) to ensure the quality and stability of the network connection.

[0003] Among the related technologies, a seamless roaming technical solution has been proposed, which enables users to maintain network connectivity and uninterrupted services when moving between different access points in a wireless network.

[0004] However, during seamless roaming handover, non-access point devices can establish associations with both the current access point (AP) and the target AP simultaneously. This may lead to the following problems: while the current AP is sending cached downlink "old data" to the non-access point device, the target AP can also send downlink "new data" to the non-access point device. This may cause the non-access point device to have difficulty transmitting downlink data in the correct order, such as "current AP first, then target AP," which could result in communication users experiencing packet loss, call interruptions, or video stream stuttering.

[0005] The above content is only used to help understand the technical solution of this application and does not represent an admission that the above content is prior art. Summary of the Invention

[0006] The main purpose of this application is to provide a data transmission method, system, device and storage medium during roaming handover, which aims to solve the technical problem that non-access point devices have difficulty transmitting downlink data in the order of "current AP first, then target AP" during seamless roaming, which leads to packet loss, call interruption or video stream stuttering for communication users.

[0007] To achieve the above objectives, this application proposes a data transmission method during roaming handover, applied to a first access point device, the method comprising:

[0008] Acquire the first downlink data to be sent to the non-access point device; wherein, the first access point device is the access point device that the non-access point device switches to from the second access point device during roaming handover;

[0009] The first downlink data is sent to the non-access point device only after receiving the second information; wherein, the second information is used to notify the first access point device that the second downlink data on the second access point device has been sent to the non-access point device, and to allow the first access point device to send the first downlink data to the non-access point device.

[0010] Furthermore, to achieve the above objectives, this application proposes a data transmission method during roaming handover, applied to a non-access point device, the method comprising:

[0011] Receive third information from the second access point device, the third information being used to notify the non-access point device that all or part of the second downlink data on the second access point device has been sent to the non-access point device;

[0012] In response to the third information, a second information is sent to the first access point device, the second information being used to notify the first access point device that all or part of the second downlink data on the second access point device has been sent to the non-access point device, and to allow the first access point device to send all or part of the first downlink data on the first access point device to the non-access point device;

[0013] Wherein, the first access point device is the access point device that the non-access point device switches to from the second access point device during roaming handover.

[0014] Furthermore, to achieve the above objectives, this application proposes a data transmission method during roaming handover, applied to a second access point device, the method comprising:

[0015] Send a second message to a first access point device; wherein the first access point device is the access point device that the non-access point device switches to from the second access point device during roaming handover, and the second message is used to notify the first access point device that the second downlink data on the second access point device has been sent to the non-access point device, and to allow the first access point device to send the first downlink data to the non-access point device;

[0016] Alternatively, a third message may be sent to the non-access point device; wherein the third message is used to notify the non-access point device that all or part of the second downlink data on the second access point device has been sent to the non-access point device.

[0017] Furthermore, to achieve the above objectives, this application also proposes a data transmission device during roaming handover, applied to a first access point device, the device comprising:

[0018] The acquisition module is used to acquire the first downlink data to be sent to the non-access point device; wherein the first access point device is the access point device that the non-access point device switches to from the second access point device during roaming handover;

[0019] The first sending module is configured to send the first downlink data to the non-access point device only after receiving the second information; wherein the second information is used to notify the first access point device that the second downlink data on the second access point device has been sent to the non-access point device, and to allow the first access point device to send the first downlink data to the non-access point device.

[0020] Furthermore, to achieve the above objectives, this application also proposes a data transmission device during roaming handover, applied to a non-access point device, the device comprising:

[0021] A receiving module is configured to receive third information from a second access point device, the third information being used to notify the non-access point device that all or part of the second downlink data on the second access point device has been sent to the non-access point device.

[0022] The second sending module is configured to send second information to the first access point device in response to the third information. The second information is used to notify the first access point device that all or part of the second downlink data on the second access point device has been sent to the non-access point device, and to allow the first access point device to send all or part of the first downlink data on the first access point device to the non-access point device.

[0023] Wherein, the first access point device is the access point device that the non-access point device switches to from the second access point device during roaming handover.

[0024] Furthermore, to achieve the above objectives, this application also proposes a data transmission device during roaming handover, applied to a second access point device, the device comprising:

[0025] The third sending module is used for:

[0026] Send a second message to a first access point device; wherein the first access point device is the access point device that the non-access point device switches to from the second access point device during roaming handover, and the second message is used to notify the first access point device that the second downlink data on the second access point device has been sent to the non-access point device, and to allow the first access point device to send the first downlink data to the non-access point device;

[0027] Alternatively, a third message may be sent to the non-access point device; wherein the third message is used to notify the non-access point device that all or part of the second downlink data on the second access point device has been sent to the non-access point device.

[0028] Furthermore, to achieve the above objectives, this application also proposes a data transmission system during roaming handover, the system comprising a first access point device, a second access point device, and a non-access point device; wherein the first access point device is used to perform the following steps:

[0029] Acquire the first downlink data to be sent to the non-access point device; wherein, the first access point device is the access point device that the non-access point device switches to from the second access point device during roaming handover;

[0030] The first downlink data is sent to the non-access point device only after receiving the second information; wherein, the second information is used to notify the first access point device that the second downlink data on the second access point device has been sent to the non-access point device, and to allow the first access point device to send the first downlink data to the non-access point device.

[0031] In addition, to achieve the above objectives, this application also proposes a data transmission device, the device comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, the computer program being configured to implement the steps of the data transmission method during the roaming handover process as described above.

[0032] In addition, to achieve the above objectives, this application also proposes a storage medium, which is a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, it implements the steps of the data transmission method during the roaming handover process as described above.

[0033] In addition, to achieve the above objectives, this application also provides a computer program product, which includes a computer program that, when executed by a processor, implements the steps of the data transmission method during the roaming handover process as described above.

[0034] One or more technical solutions proposed in the embodiments of this application have at least the following technical effects:

[0035] During roaming handover, the access device between the non-access point device and the network-side device is switched from the second access point device (i.e., the current AP) to the first access point device (i.e., the target AP). To ensure that the access point device can transmit downlink data to the non-access point device in order during roaming handover, in this application, after the first access point device obtains the first downlink data to be sent to the non-access point device, it does not immediately send it to the non-access point device. Instead, it sends the first downlink data to the non-access point device only after receiving the second information. Receiving the second information means that the second downlink data (i.e., the "old data") on the second access point device has been sent to the non-access point device. At this time, the first access point device is allowed to send the first downlink data (i.e., the "new data") to the non-access point device. This ensures that during the roaming handover of the non-access point device, downlink data is transmitted in order of "current AP first, then target AP," thereby effectively solving problems such as packet loss, call interruption, or video stream stuttering encountered by communication users during roaming handover. Attached Figure Description

[0036] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0037] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 This is a schematic diagram of a non-AP MLD during the roaming handover process in related technologies;

[0039] Figure 2 This is one of the flowcharts illustrating a data transmission method during roaming handover proposed in an embodiment of this application;

[0040] Figure 3 This is a second flowchart illustrating a data transmission method during roaming handover proposed in an embodiment of this application;

[0041] Figure 4 This is the third flowchart illustrating a data transmission method during roaming handover proposed in this application embodiment;

[0042] Figure 5 This is the fourth flowchart illustrating a data transmission method during roaming handover proposed in this application embodiment;

[0043] Figure 6This is the fifth flowchart illustrating a data transmission method during roaming handover proposed in this application embodiment;

[0044] Figure 7 This is a sixth flowchart illustrating a data transmission method during roaming handover proposed in an embodiment of this application;

[0045] Figure 8 This is the seventh flowchart illustrating a data transmission method during roaming handover proposed in this application embodiment;

[0046] Figure 9 This is the eighth flowchart illustrating a data transmission method during roaming handover proposed in this application embodiment;

[0047] Figure 10 This is the ninth flowchart illustrating a data transmission method during roaming handover proposed in an embodiment of this application;

[0048] Figure 11 This is a schematic diagram illustrating the format of a roaming request confirmation message in a data transmission method during roaming handover, as proposed in an embodiment of this application.

[0049] Figure 12 This is a schematic diagram illustrating the format of a fast roaming notification message in a data transmission method during roaming handover proposed in an embodiment of this application;

[0050] Figure 13 This is a schematic diagram of the FT request frame body of the fast roaming notification message in a data transmission method during roaming handover proposed in an embodiment of this application;

[0051] Figure 14 This is the tenth flowchart illustrating a data transmission method during roaming handover proposed in this application embodiment;

[0052] Figure 15 This is eleventh of a flowchart illustrating a data transmission method during roaming handover proposed in an embodiment of this application;

[0053] Figure 16 This is the twelfth flowchart illustrating a data transmission method during roaming handover as proposed in this application embodiment;

[0054] Figure 17 This is one of the structural schematic diagrams of a data transmission device during roaming handover proposed in an embodiment of this application;

[0055] Figure 18 This is a second schematic diagram of the structure of a data transmission device during roaming handover, as proposed in an embodiment of this application.

[0056] Figure 19This is the third schematic diagram of a data transmission device in the roaming handover process proposed in the embodiments of this application;

[0057] Figure 20 This is a schematic diagram of the structure of a data transmission device proposed in an embodiment of this application.

[0058] The purpose, features, and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0059] It should be understood that the specific embodiments described herein are merely illustrative of the technical solutions of this application and are not intended to limit this application.

[0060] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0061] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0062] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0063] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0064] To better understand the technical solution of this application, the relevant technologies involved in this application will be explained as follows.

[0065] (a) FT (Fast Basic Service Set Transition) roaming;

[0066] The 802.11 FT protocol is designed to reduce the time gaps between a STA and its DS (distribution system) during BSS (Basic Service Set) transitions. The FT protocol is part of the reassociation service and applies only to STA roaming between APs within the same mobility domain and within the same ESS (Extended Service Set). The FT protocol requires the exchange of information during the initial association (or subsequent reassociation) between the STA (called the FT Initiator (FTO)) and the AP.

[0067] The initial exchange is called the FT initial mobility domain association. When the FT establishes the initial RSN (Robust Security Network) connection in the mobility domain, the STA will sequentially go through authentication, association, and the establishment of RSNA (robust security network association).

[0068] During FT execution, the STA's state changes from State 1 to State 4, and its 802.1X controlled port is eventually unlocked. Consequently, the STA upgrades from only being able to send and receive Type 1 frames to being able to send and receive Type 1, 2, and 3 frames. When the STA roams, due to the need to reassociate with the target AP, its state drops from State 4 to State 2, and it can only send and receive Type 1 and 2 frames. Therefore, within the FT protocol framework, STA roaming will cause its service interruption. The length of the transition time from State 2 to State 4 during roaming and the restoration of Type 3 frame transmission and reception capabilities determines the STA's user experience.

[0069] (ii) Block Ack process;

[0070] The 802.11 baseline Block Ack procedure is as follows:

[0071] The MAC layer processing architecture of Block Ack is shown in the figure below. After completing Deaggregation Control, the front-end of the receiver requires subsequent processing to implement Receive Reordering Buffer Control. That is, the received MPDU (Medium Protocol Data Unit) is sorted according to the sequence number using TA (transmitter address or transmitting station address) / TID (traffic identifier) ​​as the granularity. This ensures that the MSDU (Medium Service Data Unit) or A-MSDU (aggregate MAC service data unit) received downstream of MAC (Media Access Control) are arranged in the order of the sequence number when output.

[0072] (iii) Link management of Multi-Link Device (MLD);

[0073] 1) Link (connection) state management in TID-to-link Mapping (TTLM negotiation);

[0074] The TID-to-link mapping mechanism allows non-AP MLDs (non-access point devices) and AP MLDs (access point devices) to allocate how data frames are transmitted on the setup link (connection establishment) in both the uplink and downlink directions on a per-TID basis; by default, all TIDs should be mapped to all uplink and downlink setup links.

[0075] When both AP MLD and non-AP MLD support TID-to-link Mapping negotiation, the mapping flexibility varies depending on the value of the TID-to-linkMapping Negotiation Support subfield.

[0076] <1> When TID-to-link Mapping Negotiation Support subfield = 1, all TIDs are mapped to the same set of links;

[0077] <2> When TID-to-link Mapping Negotiation Support subfield=3, TIDs can be mapped to the same or different sets of links.

[0078] For a non-AP MLD's TID, if one TID is mapped to a setup link, then that link is called an enabled link of the non-AP MLD; if no TID is mapped to a setup link, then that link is called a disabled link of the non-AP MLD.

[0079] Non-AP MLDs cannot transmit data frames on disabled links, but they can transmit Type 1 and Type 2 management frames, Type 1 control frames, and TID-to-link Mapping request (TTLM request), resp (TTLM response), and teardown (TTLM cancellation) frames.

[0080] 2) Power state management;

[0081] Once a TID-to-link mapping is successfully negotiated through a link and the corresponding link is updated to the enabled state, the non-AP STA is in the Active state.

[0082] After successfully negotiating TID-to-link mapping with another link for the target link, the target link is updated to the enabled state, but the non-AP STA remains in the doze state of power saving mode.

[0083] The following is a detailed description in conjunction with the accompanying drawings and specific implementation methods.

[0084] When discussing seamless roaming under the 802.11 protocol framework, the AP MLD associated with a non-AP MLD before roaming is usually referred to as the current AP MLD, also known as the serving AP MLD, while the newly associated AP MLD during roaming is usually referred to as the target AP MLD.

[0085] Non-AP MLDs typically pre-select a set of candidate AP MLDs. When certain triggering conditions are met, the target AP MLD is selected from several candidate AP MLDs, and then the roaming process is initiated.

[0086] Figure 1 This is a schematic diagram of a non-AP MLD during the roaming handover process in related technologies, such as... Figure 1 As shown, a non-APMLD will select a target AP MLD from several candidate AP MLDs and initiate roaming. During this process, it will establish an association with both the current AP MLD and the target AP MLD. The DS mapping will also change from the current AP MLD to the target AP MLD. Accordingly, the DS will transfer the new DL (DownLink) data to the target AP MLD. This will result in a transition situation where the downlink "old data" cached by the current AP MLD and the downlink "new data" cached by the target AP MLD coexist.

[0087] It should be noted that, as Figure 1 As shown, the current AP MLD can include multiple APs, such as AP1 and AP2 in the figure. The target AP MLD can include multiple APs, such as AP3 and AP4 in the figure. The non-AP MLD can include multiple STAs, such as STA1 and STA2 in the figure. For example, the STA associated between the non-AP MLD and the current AP MLD in the figure is STA1, and the STA associated between the non-AP MLD and the target AP MLD is STA2. AP1 can send downlink data from the DS to STA1, and AP4 can send downlink data from the DS to STA2.

[0088] To achieve seamless roaming with zero packet loss, the MAC layer, in addition to synchronizing the necessary MAC context information, should also ensure that new and old data are sequentially transmitted to the upper-layer application according to the DS distribution order. Improper handling can lead to problems such as packet loss and service interruption in downlink services.

[0089] When the two AP MLDs before and after roaming, namely the current AP MLD and the target AP MLD, negotiate to send the downlink data of the current AP MLD first (via... Figure 1 Path ①), then send to target AP MLD (via Figure 1By determining the order of downlink TID cached data on path ②), the ordered transmission of data between AP MLDs can be achieved with a small context synchronization cost, thus reducing communication overhead.

[0090] To address the aforementioned application scenarios, this application proposes a data transmission method during roaming handover, aiming to achieve serial sequential transmission of downlink TID buffered data between different AP MLDs. This method enables the orderly transmission of downlink buffered data between AP MLDs without performing dynamic real-time context synchronization. This approach is highly compatible with cost-sensitive terminal devices and effectively reduces communication overhead.

[0091] It should be noted that the executing entity of the embodiments of this application can be a computing service device with data processing, network communication, and program execution functions, such as a tablet computer, personal computer, or mobile phone, or an electronic device or terminal system capable of realizing the above functions. The following uses a data transmission device as an example to describe the embodiments of this application and the following embodiments.

[0092] The data transmission method, system, device, and storage medium during the roaming handover process provided in the embodiments of this application will be described in detail below.

[0093] According to one aspect, embodiments of this application provide a data transmission method during roaming handover, applied to a first access point device (e.g., a target AP MLD). Figure 2 This is one of the flowcharts illustrating a data transmission method during roaming handover proposed in an embodiment of this application, as shown below. Figure 2 As shown, the data transmission method during the roaming handover process includes steps S201 to S202:

[0094] Step S201: Obtain the first downlink data to be sent to the non-access point device;

[0095] Wherein, the first access point device is the access point device that the non-access point device switches to from the second access point device during roaming handover.

[0096] It should be noted that during the roaming handover process of a non-access point device, the non-access point device and the network-side device (such as DS) will be associated with the original second access point device and the newly roaming first access point device at the same time. At this time, the original second access point device will obtain the second downlink data to be sent to the non-access point device from the network-side device, and the newly roaming first access point device will obtain the first downlink data to be sent to the non-access point device from the network-side device.

[0097] It should also be noted that non-access point devices are, for example, non-AP MLDs, first access point devices are, for example, target AP MLDs, and second access point devices are, for example, current AP MLDs.

[0098] Step S202: After receiving the second information, the first downlink data is sent to the non-access point device.

[0099] The second information is used to notify the first access point device that the second downlink data on the second access point device has been sent to the non-access point device, and to allow the first access point device to send the first downlink data to the non-access point device.

[0100] Specifically, in order to ensure that the original second access point device sends the second downlink data to the non-access point device first, and then the newly roaming first access point device sends the acquired first downlink data to the non-access point device, the newly roaming first access point device can cache the first downlink data in the first access point device after acquiring it and not send it temporarily. After receiving the second information, it is considered that the second downlink data on the second access point device has been sent to the non-access point device, and then the cached first downlink data is sent to the non-access point device. This ensures that the downlink data is transmitted in the correct order according to the order of "second access point device first, then first access point device".

[0101] In some embodiments, during the roaming handover process of a non-access point device, although the non-access point device and the network-side device are simultaneously associated with the original second access point device and the newly roaming first access point device, there may be a situation where the network-side device does not temporarily send the first downlink data to the first access point device. That is, the first access point device may not have temporarily obtained the first downlink data that needs to be sent to the non-access point device. In this case, the first access point device may also receive the second information first, indicating that the first access point device can support sending the first downlink data. After the first access point device obtains the first downlink data, it can send the first downlink data to the non-access point device.

[0102] In this embodiment, to enable the access point device to transmit downlink data to the non-access point device in the correct order during roaming handover, the first access point device, after acquiring the first downlink data to be sent to the non-access point device, does not immediately send it to the non-access point device. Instead, it sends the first downlink data to the non-access point device only after receiving the second information. Receiving the second information means that the second downlink data (i.e., the aforementioned "old data") on the second access point device has already been sent to the non-access point device. At this time, the first access point device is allowed to send the first downlink data (i.e., the aforementioned "new data") to the non-access point device. This ensures that during the roaming handover of the non-access point device, downlink data is transmitted in the correct order according to the sequence of "current AP first, then target AP," thereby effectively solving problems such as packet loss, call interruption, or video stream stuttering encountered by communication users during roaming handover.

[0103] In some embodiments, Figure 3 This is a second flowchart illustrating a data transmission method during roaming handover proposed in an embodiment of this application, as shown below. Figure 3 As shown, in Figure 2 Based on step S202, steps S203 to S204 are also included before step S202:

[0104] Step S203: Receive the first information;

[0105] The first information is used to prohibit the first access point device from sending the first downlink data to the non-access point device.

[0106] Step S204: In response to the first information, the transmission of the first downlink data to the non-access point device is prohibited.

[0107] Specifically, before receiving the second information, the first access point device can first receive the first information to prohibit the first access point device from sending the first downlink data to the non-access point device. In response to the first information, the first access point device will stop sending the first downlink data to the non-access point device and wait for the second access point device to send the second downlink data to the non-access point device first. After confirming through the received second information that the second access point device has completed the downlink data transmission, the first access point device will then send the first downlink data to the non-access point device. This ensures that the downlink data is transmitted in the correct order, "second access point device first, then first access point device," thereby effectively solving problems such as packet loss, call interruption, or video stream stuttering encountered by communication users during roaming handover.

[0108] In some embodiments, a specific implementation is provided in which a non-access point device instructs a first access point device to prohibit the transmission of first downlink data via first information. Figure 4This is the third flowchart illustrating a data transmission method during roaming handover proposed in this application embodiment, as shown below. Figure 4 As shown, in Figure 3 Based on this, step S203 specifically includes step S203-1:

[0109] Step S203-1: Receive first information from the non-access point device;

[0110] The first information is used to notify the first access point device that the power management status of the non-access point device is in power-saving mode.

[0111] Specifically, the first information received by the first access point device can come from a non-access point device. That is, the non-access point device instructs the first access point device to prohibit the transmission of first downlink data via the first information. Specifically, the first information can be used to notify the first access point device that the power management state of the non-access point device is in power-saving mode, i.e., PowerSave mode. After receiving such first information, even if the first access point device receives new first downlink data destined for the non-access point device from the network side device, it will not transmit it to the non-access point device. It should be noted that in this embodiment, the first access point device setting the TID to a link disabled or enabled state applies only to the link between the first access point device and the non-access point device, excluding links between other access point devices and non-access point devices.

[0112] It should be noted that although the non-access point device indicates to the first access point device that the power management state of the non-access point device is in power-saving mode by sending the first information, this application does not limit whether the non-access point device is actually in PowerSave mode at this time. That is, the non-access point device only announces to the first access point device that the non-access point device is in PowerSave mode by sending the first information, thereby prohibiting the first access point device from sending downlink data to the non-access point device, without considering whether the non-access point device is actually in PowerSave mode at this time.

[0113] In some embodiments, a specific implementation is provided in which a non-access point device instructs a first access point device to send first downlink data via second information. For example... Figure 4 As shown, step S202 specifically includes steps S202-11 and S202-12:

[0114] Step S202-11: Receive second information from the non-access point device;

[0115] The second information is used to notify the first access point device that the power management status of the non-access point device has been switched to active mode.

[0116] In step S202-12, the first downlink data is sent to the non-access point device only in response to the second information.

[0117] Specifically, the second information received by the first access point device can come from the non-access point device. That is, the non-access point device instructs the first access point device to allow the transmission of the first downlink data through the second information. Specifically, the second information can be used to notify the first access point device that the power management state of the non-access point device has been switched to active mode. After receiving such second information, the first access point device can send the newly received downlink data to the non-access point device, thus ensuring the ordered transmission of data between access point devices.

[0118] It should be noted that although the non-access point device indicates to the first access point device that the power management state of the non-access point device is active mode by sending the second information, this application does not limit whether the non-access point device is actually in active mode at this time. That is, the non-access point device only announces to the first access point device that the non-access point device is in active mode by sending the second information, thereby allowing the first access point device to send downlink data to the non-access point device, without considering whether the non-access point device is actually in active mode at this time.

[0119] In some embodiments, the second information may be sent by the non-access point device in response to the fact that all the second downlink data on the second access point device has been sent to the non-access point device.

[0120] Specifically, the second downlink data may include multiple data streams. After determining that all the second downlink data on the second access point device has been sent to the non-access point device, that is, after determining that all the data streams of the second downlink data have been sent, the non-access point device may send the second information to the first access point device to instruct the first access point device to allow the first downlink data to be sent to the non-access point device.

[0121] In some embodiments, the specific implementation of prohibiting the transmission of the first downlink data to the non-access point device in response to the first information may include:

[0122] In response to the first information, the transmission of downlink data corresponding to all TIDs in the first downlink data to the non-access point device is prohibited.

[0123] It should be noted that the second downlink data may include multiple data streams, which can be identified by TIDs. TIDs are usually used to identify and distinguish different types of data streams to ensure data priority and service quality.

[0124] Specifically, in response to first information used to indicate that the power management state of the non-access point device is in power-saving mode, the first access point device prohibits sending downlink data corresponding to all TIDs in the first downlink data to the non-access point device.

[0125] In some embodiments, the specific implementation of sending the first downlink data to the non-access point device in response to the second information may include:

[0126] In response to the second information, downlink data corresponding to all TIDs in the first downlink data is sent to the non-access point device.

[0127] Specifically, in response to the second information used to notify the non-access point device that the power management state has been switched to active mode, the first access point device sends downlink data corresponding to all TIDs in the first downlink data to the non-access point device. This can also be understood as the first access point device supporting the sending of downlink data corresponding to any TID to the non-access point device at this time. As for the order in which the first access point device sends downlink data corresponding to different TIDs, this application does not impose any restrictions.

[0128] The following example illustrates the method (link-level control) for controlling the downlink transmission of the first access point device from the non-access point device:

[0129] When a non-AP MLD initiates a roaming request to the current AP MLD, the current AP MLD can determine the specific cooperation method among the current AP MLD, the target AP MLD, and the non-AP MLD by combining a series of conditions. The specific process is as follows:

[0130] 1) When the current AP MLD receives a roaming request, if the current AP MLD and the target AP MLD negotiate to send the cached DL TID data (i.e., the aforementioned downlink data) serially, and the non-AP MLD and the target AP MLD do not simultaneously support TTLM negotiation per TID (mode is not equal to 3), then the current AP MLD can instruct the non-AP MLD to perform the following link-level control from the user side:

[0131] 1-a) When a non-AP MLD receives a notification from the current AP MLD, it establishes an initial association with the target AP MLD. The STA on the non-AP MLD will announce to the target AP MLD that it has entered PowerSave mode. After the DS Mapping changes during roaming, even if the target AP MLD receives new downlink data from the DS that is to be sent to the non-AP MLD, it will not send it to the non-AP MLD.

[0132] 1-b) After the current AP MLD finishes sending the data for a DL TID, it will set the MoreData subfield carried by the Frame Control field in the MAC frame header of the last message to 0 (i.e., MD=0) to notify the non-AP MLD that the data for that DL TID has been sent.

[0133] 1-c) When the non-AP MLD confirms through the above mechanism that all buffered data of DLTIDs in the current AP MLD has been sent, it can notify the target AP MLD that the non-AP MLD has entered Active mode when sending data or management frames (e.g., PM=0) to the target AP MLD. At this time, the target AP MLD can send the buffered data of the newly received DLTIDs to the non-AP MLD, ensuring the ordered transmission of data between AP MLDs.

[0134] It should be noted that the above-mentioned mode represents the TID-to-link Mapping Negotiation Support subfield. When mode=3, it means that TIDs can be mapped to the same or different link sets; when mode is not equal to 3, for example, when mode=1, it means that all TIDs are mapped to the same link set. The mode of both non-AP MLD and target AP MLD is equal to 3, which is a prerequisite for non-AP MLD and target AP MLD to support TTLM negotiation, but does not directly indicate whether non-AP MLD and target AP MLD support TTLM negotiation.

[0135] It should also be noted that sending the first message announcing entry into PowerSave mode does not only occur when there is no TTLM negotiation between the non-AP and the target AP. The fact that the non-AP and the target AP do not conduct TTLM negotiation is not a prerequisite for sending the first message announcing entry into PowerSave mode; it is merely an example.

[0136] In some embodiments, when sending the first message announcing entry into PowerSave mode, non-APs can also perform TTLM negotiation with the target AP, such as negotiating to the enabled Link state, which means TTLM is disabled and completely controlled by PowerSave mode.

[0137] In some embodiments, another specific implementation is provided in which a non-access point device instructs a first access point device to prohibit the transmission of first downlink data via first information. Figure 5 This is the fourth flowchart illustrating a data transmission method during roaming handover proposed in this application embodiment, as shown below. Figure 5 As shown, in Figure 3 Based on this, step S203 specifically includes step S203-2, and step S204 specifically includes step S204-1:

[0138] Step S203-2: Receive first information from the non-access point device;

[0139] The first information indicates one or more TIDs corresponding to the second downlink data and is used to notify the first access point device to set the one or more TIDs to a link disabled state so as to prohibit the transmission of downlink data in the first downlink data corresponding to the one or more TIDs.

[0140] Step S204-1: In response to the first information, set one or more TIDs to a link disabled state.

[0141] Specifically, the first information received by the first access point device may come from a non-access point device. That is, the non-access point device instructs the first access point device to prohibit the transmission of the first downlink data through the first information. Specifically, the first information can be used to indicate one or more TIDs corresponding to the second downlink data and notify the first access point device to set the above one or more TIDs to a link disabled state so as to prohibit the transmission of downlink data corresponding to one or more TIDs in the first downlink data.

[0142] For example, if the second access point device has cached the second downlink data TID1 to TID3, the non-access point device can instruct the first access point device to set the links corresponding to TID1 to TID3 in its downlink to a disabled state, i.e., a "disabled link" state, through the first information. In this way, the first access point device cannot send the downlink data corresponding to TID1 to TID3 in the first downlink data, so as to ensure that the second access point device sends the second downlink data TID1 to TID3 first, and then the first access point device sends the first downlink data corresponding to TID1 to TID3.

[0143] It should be noted that the first information does not indicate that the first access point device is prohibited from sending downlink data other than TID1 to TID3. For example, the first access point device can support sending the first downlink data corresponding to TID5 to non-access point devices. This is because the second access point device does not cache the second downlink data corresponding to TID5. Therefore, even if the first access point device sends the first downlink data corresponding to TID5, it will not affect the ordered transmission of the downlink data corresponding to TID5.

[0144] In some embodiments, another specific implementation is provided in which a non-access point device instructs a first access point device to send first downlink data via second information. For example... Figure 5 As shown, step S202 specifically includes steps S202-21 to S202-23:

[0145] Step S202-21: Receive second information from the non-access point device;

[0146] The second information indicates one or more TIDs corresponding to all downlink data that have been sent to the non-access point device in the second downlink data, and is used to notify the first access point device to set the one or more TIDs to the link enabled state.

[0147] Step S202-22: In response to the second information, the one or more TIDs indicated by the second information are set to the link enabled state.

[0148] Step S202-23: Send the downlink data in the first downlink data corresponding to the one or more TIDs indicated by the second information to the non-access point device.

[0149] Specifically, the second information received by the first access point device can come from the non-access point device. That is, the non-access point device instructs the first access point device to allow the transmission of the first downlink data through the second information. Specifically, the second information can be used to indicate one or more TIDs corresponding to all downlink data that have been sent to the non-access point device in the second downlink data, and to notify the first access point device to set the above one or more TIDs to the link enabled state. Thus, in response to the second information, the first access point device can set the one or more TIDs indicated by the second information to the link enabled state, and then send the downlink data in the first downlink data corresponding to the one or more TIDs indicated by the second information to the non-access point device.

[0150] For example, if the second access point device has already sent the second downlink data corresponding to TID1 to the non-access point device, the non-access point device can instruct the first access point device to set the link corresponding to TID1 in its downlink to the "enabled Link" state through the second information. In this way, the first access point device can send the downlink data corresponding to TID1 in the first downlink data, so as to ensure that the second access point device sends the second downlink data of TID1 first, and then the first access point device sends the first downlink data corresponding to TID1.

[0151] In some embodiments, the above Figure 4 , 5 In a corresponding embodiment, the first information and the second information can be carried in the TTLM negotiation message between the non-access point device and the first access point device.

[0152] Specifically, the aforementioned first and second information can be carried through TTLM negotiation messages between the non-access point device and the first access point device. The TTLM negotiation messages may include TTLM request messages and TTLM response messages.

[0153] For example, the TTLM negotiation message includes the mapping relationship between each TID and the link status of the first access point device, such as the following mapping relationship:

[0154] TID1→enabled Link; TID2→enabled Link; TID3→enabled Link.

[0155] If the second access point device has cached downlink data corresponding to TID1 and TID3 at this time, the non-access point device can modify the mapping relationship using the first information:

[0156] TID1→disabled Link; TID2→enabled Link; TID3→disabled Link.

[0157] After the second access point device sends the downlink data corresponding to TID1 to the non-access point device, the non-access point device can then modify the mapping relationship using the first information:

[0158] TID1→enabled Link; TID2→enabled Link; TID3→disabled Link.

[0159] After the second access point device sends the downlink data corresponding to TID3 to the non-access point device, the non-access point device can modify the mapping relationship again using the first information:

[0160] TID1→enabled Link; TID2→enabled Link; TID3→enabled Link, which means that downlink data transmission is supported on the links TID1 to TID3 of the first access point device.

[0161] The following example illustrates the method of independently disabling and activating TIDs (TID-level control) for the downlink transmission of the first access point device controlled by the non-access point device:

[0162] 2) When the current AP MLD receives a roaming request, if the current AP MLD and the target AP MLD negotiate to send these DL TID cached data serially, and the non-AP MLD and the target AP MLD both support per-TID TTLM negotiation (mode is equal to 3), then the current AP MLD can notify the non-AP MLD to perform TID-level control:

[0163] 2-a) When the non-AP MLD receives a notification from the current AP MLD, it establishes an initial association with the target AP MLD. The STA on the non-AP MLD will negotiate TTLM with the target AP MLD, so that the TIDs with downlink data cached on the current AP MLD enter the "disabled Link" state on the new association link. After the DS Mapping changes during roaming, even if the target AP MLD receives new data from the DS for these DL TIDs sent to the non-AP MLD, it will not send them to the non-AP MLD from the new association link.

[0164] 2-b) After the current AP MLD finishes sending the data for a DL TID, it will set the MoreData subfield carried by the Frame Control field in the MAC frame header of the last packet to 0, in order to notify the non-AP MLD that the data for that DL TID has been sent.

[0165] 2-c) Whenever the non-AP MLD receives a DL TID buffered data transmission completed by the current AP MLD, it can re-negotiate TTLM with the target AP MLD to make this DL TID enter the "enabled Link" state on the new associated link. At this time, the target AP MLD sends the newly received DL TID buffered data to the non-AP MLD, which can ensure the ordered transmission of data between AP MLDs.

[0166] The above 2-b) and 2-c) cyclic operations are repeated until all DL TIDs enter the "enabled Link" state on the new associated link of the target AP MLD, thus enabling the orderly transmission of downlink data during roaming handover.

[0167] In some embodiments, a specific implementation is provided in which the second access point device instructs the first access point device to prohibit the transmission of the first downlink data through first information. Figure 6 This is the fifth flowchart illustrating a data transmission method during roaming handover proposed in this application embodiment, as shown below. Figure 6 As shown, in Figure 3 Based on this, step S203 specifically includes step S203-3:

[0168] Step S203-3: Receive first information from the second access point device;

[0169] The first information indicates one or more TIDs corresponding to the second downlink data.

[0170] Specifically, the first information received by the first access point device can also come from the second access point device. That is, the second access point device instructs the first access point device to prohibit the transmission of the first downlink data through the first information. Specifically, the first information can be used to instruct the first access point device to prohibit the transmission of the downlink data corresponding to the second downlink data cached by the second access point device. In this way, the first access point device is instructed to prohibit the transmission of downlink data corresponding to the one or more TIDs, so as to ensure the orderly transmission of downlink data.

[0171] In some embodiments, a specific implementation is provided in which a second access point device instructs a first access point device to send first downlink data via second information. For example... Figure 6 As shown, step S202 specifically includes steps S202-31 and S202-32:

[0172] Step S202-31: Receive second information from the second access point device;

[0173] The second information indicates the TID corresponding to the downlink data that has been sent to the non-access point device in the second downlink data.

[0174] In step S202-32, in response to the second information, the downlink data corresponding to the TID indicated by the second information in the first downlink data is sent to the non-access point device.

[0175] Specifically, the second information received by the first access point device can also come from the second access point device. That is, the second access point device instructs the first access point device to allow the transmission of the first downlink data through the second information. Specifically, the second information can be used to indicate the TID corresponding to the downlink data in the second downlink data that has been sent to the non-access point device. In response to the second information, the first access point device can send the downlink data in the first downlink data corresponding to the TID indicated by the second information to the non-access point device to ensure the ordered transmission of the downlink data.

[0176] In some embodiments, the TID mentioned in any of the above embodiments can be a downlink TID, which can be understood as identifying different data streams in the downlink data.

[0177] In some embodiments, the above Figure 6 In a corresponding embodiment, the first information and the second information can be carried in the context transmission interaction message between the first access point device and the second access point device.

[0178] Specifically, for a scheme in which the second access point device controls the first access point device to prohibit or allow the transmission of downlink data through the first information and the second information, the first information and the second information can be carried in the context transfer interaction message (i.e., the context transfer message) between the first access point device and the second access point device, or they can be carried in other interaction messages between the first access point device and the second access point device. This application is only an example and does not impose any limitations.

[0179] The following example illustrates how the second access point device controls the independent disabling and activation of the downlink TID transmitted by the first access point device:

[0180] 3) When the current AP MLD receives a roaming request, if the current AP MLD and the target AP MLD negotiate to send these DL TID cached data serially, the current AP MLD can negotiate with the target AP MLD to have the target AP MLD perform DL TID-level control:

[0181] 3-a) When the target AP MLD receives a notification from the current AP MLD, the target AP MLD records the TIDs that have downlink data on the current AP MLD and suspends the transmission of these TIDs on the new associated link. After the DS Mapping changes during roaming, even if the target AP MLD receives new data of these DL TIDs sent to the non-AP MLD from the DS, it will not send them to the non-AP MLD from the new associated link.

[0182] 3-b) Each time the current AP MLD finishes sending data for a DL TID, it will notify the target AP MLD that it has finished sending data for a DL TID.

[0183] 3-c) Once the target AP MLD receives a notification that the current AP MLD has completed the transmission of a DL TID data, it can continue to transmit the data corresponding to that DL TID on the new associated link, which can also ensure the ordered transmission of data between AP MLDs.

[0184] The above 3-b) and 3-c) cyclic operations are repeated until all DL TIDs are restored to a transmittable state on the new associated link of the target AP MLD, thus achieving ordered transmission of downlink data during roaming handover.

[0185] According to another aspect, embodiments of this application provide a data transmission method during roaming handover, applicable to non-access point devices (e.g., non-AP MLDs). Figure 7 This is the sixth flowchart illustrating a data transmission method during roaming handover proposed in this application embodiment, as shown below. Figure 7 As shown, the data transmission method during the roaming handover process includes steps S701 to S702:

[0186] Step S701: Receive third information from the second access point device;

[0187] The third information is used to notify the non-access point device that all or part of the second downlink data on the second access point device has been sent to the non-access point device.

[0188] Step S702: In response to the third information, send the second information to the first access point device;

[0189] The second information is used to notify the first access point device that all or part of the second downlink data on the second access point device has been sent to the non-access point device, and to allow the first access point device to send all or part of the first downlink data on the first access point device to the non-access point device.

[0190] Wherein, the first access point device is the access point device that the non-access point device switches to from the second access point device during roaming handover.

[0191] Specifically, the non-access point device can receive third information from the second access point device, which is used to notify the non-access point device that all or part of the second downlink data on the second access point device has been sent to the non-access point device. In response to the third information, the non-access point device can send second information to the first access point device to notify the first access point device that all or part of the second downlink data on the second access point device has been sent to the non-access point device, and allow the first access point device to send all or part of the first downlink data on the first access point device to the non-access point device.

[0192] It should be noted that the second information indicating the first downlink data that the first access point device is allowed to send must correspond to the second downlink data that has been sent by the second access point device. For example, the two must have the same TID to ensure that the downlink data is transmitted in order at the TID level, thereby effectively solving problems such as packet loss, call interruption or video stream stuttering encountered by communication users during roaming handover.

[0193] In some embodiments, Figure 8 This is the seventh flowchart illustrating a data transmission method during roaming handover proposed in this application embodiment, as shown below. Figure 8 As shown, in Figure 7 Based on this, steps S703 to S704 are included before step S701:

[0194] Step S703: Receive fourth information from the second access point device;

[0195] The fourth information is used to notify the non-access point device that the second access point device stores second downlink data to be sent to the non-access point device.

[0196] Step S704: In response to the fourth information, send the first information to the first access point device;

[0197] The first information is used to prohibit the first access point device from sending the first downlink data to the non-access point device.

[0198] Specifically, before receiving the third information from the second access point device, the non-access point device can first receive the fourth information from the second access point device. The fourth information is used to notify the non-access point device that the second access point device has stored the second downlink data to be sent to the non-access point device. In response to the fourth information, the non-access point device will send the first information to the first access point device to prevent the first access point device from sending the first downlink data to the non-access point device. After the second access point device sends all or part of the second downlink data, the first access point device will then send the corresponding all or part of the first downlink data to the non-access point device to ensure that the downlink data is transmitted in order according to the sequence of "second access point device first, then first access point device".

[0199] It should be noted that the aforementioned fourth information can either indirectly instruct the first access point device to prohibit the first access point device from sending all of the first downlink data to the non-access point device, or it can only indirectly instruct the first access point device to prohibit the first downlink device from sending the portion of the first downlink data that has the same TID as the second downlink data to the non-access point device. This application does not impose any restrictions on this.

[0200] In some embodiments, the fourth information may include information for indicating the TID corresponding to the second downlink data.

[0201] Specifically, the fourth information may include information indicating the TID corresponding to the second downlink data, so that the non-access point device can determine which TIDs in the first access point device need to be blocked from sending downlink data, and then control through the first information to ensure the ordered transmission of downlink data.

[0202] In some embodiments, the fourth information may further include information for instructing the non-access point device not to perform TTLM negotiation with the first access point device.

[0203] Specifically, the fourth information may include information for instructing the non-access point device not to perform TTLM negotiation with the first access point device. In response to the fourth information, the non-access point device may adopt a link-level control strategy to disable or enable downlink data transmission of the first access point device.

[0204] In some embodiments, a specific implementation is provided in which a non-access point device instructs a first access point device to prohibit the transmission of first downlink data via first information. The first information is used to notify the first access point device that the power management state of the non-access point device is in power-saving mode, thereby prohibiting the first access point device from transmitting the first downlink data to the non-access point device.

[0205] Specifically, the non-access point device sends a first message to the first access point device, which can be used to notify the non-access point device that its power management state is in power-saving mode, thereby prohibiting the first access point device from sending the first downlink data to the non-access point device.

[0206] In some embodiments, a specific implementation is provided whereby a non-access point device instructs a first access point device to send first downlink data via second information. The specific implementation of sending the second information to the first access point device in response to the third information may include:

[0207] In response to the third information indicating that all of the second downlink data on the second access point device has been sent to the non-access point device, a second information is sent to the first access point device, wherein the second information is used to notify the first access point device that the power management state of the non-access point device has been switched to active mode, thereby allowing the first access point device to send the first downlink data to the non-access point device.

[0208] Specifically, in response to the third information indicating that all the second downlink data on the second access point device has been sent to the non-access point device, the non-access point device can send a second information to the first access point device to notify the first access point device that the power management state of the non-access point device has been switched to active mode, thereby allowing the first access point device to send the first downlink data to the non-access point device, ensuring the ordered transmission of downlink data.

[0209] In some embodiments, the fourth information may further include information for instructing the non-access point device to perform TTLM negotiation with the first access point device.

[0210] Specifically, the fourth information may include information for instructing the non-access point device to perform TTLM negotiation with the first access point device. In response to the fourth information, the non-access point device may adopt a TID-level control strategy to disable or enable downlink data transmission of the first access point device.

[0211] In some embodiments, a non-access point device is provided to instruct a first access point device to prohibit the transmission of first downlink data via first information. The first information indicates one or more TIDs corresponding to the second downlink data and is used to notify the first access point device to set the one or more TIDs to a link-disabled state, thereby prohibiting the transmission of downlink data in the first downlink data corresponding to the one or more TIDs.

[0212] Specifically, the non-access point device sends first information to the first access point device. This first information can be used to indicate one or more TIDs corresponding to the second downlink data and to notify the first access point device to set the one or more TIDs to a link disabled state so as to prohibit the transmission of downlink data in the first downlink data corresponding to the one or more TIDs.

[0213] In some embodiments, another specific implementation is provided whereby a non-access point device instructs a first access point device to send first downlink data via second information. The specific implementation of sending the second information to the first access point device in response to the third information may include:

[0214] In response to the third information indicating that all downlink data corresponding to one or more TIDs of the TIDs corresponding to the second downlink data has been sent to the non-access point device, the second information is sent to the first access point device;

[0215] The second information indicates the one or more TIDs and notifies the first access point device to set the one or more TIDs to a link-enabled state, so that the first access point device can send downlink data corresponding to the one or more TIDs in the first downlink data to the non-access point device.

[0216] Specifically, in response to the third information indicating that all downlink data corresponding to one or more TIDs in the TIDs corresponding to the second downlink data has been sent to the non-access point device, the non-access point device can send the second information to the first access point device to indicate the one or more TIDs and notify the first access point device to set the one or more TIDs to the link enabled state, so that the first access point device can send the downlink data corresponding to the one or more TIDs in the first downlink data to the non-access point device, thus ensuring the ordered transmission of downlink data.

[0217] In some embodiments, the first information and the second information described above are carried in the TTLM negotiation message between the non-access point device and the first access point device.

[0218] In some embodiments, Figure 9 This is the eighth flowchart illustrating a data transmission method during roaming handover proposed in this application embodiment, as shown below. Figure 9 As shown, in Figure 8 Based on step S703, step S705 is included before step S703:

[0219] Step S705: Send a roaming request message to the second access point device;

[0220] The roaming request message requests that the non-access point device be switched from the second access point device to the first access point device during roaming handover.

[0221] Specifically, the non-access point device can first send a roaming request message to the second access point device to request that the non-access point device be switched from the second access point device to the first access point device during roaming handover. Then, the second access point device combines a series of conditions to determine the specific cooperation method between the second access point device, the first access point device, and the non-access point device.

[0222] In some embodiments, the TID can be a downlink TID.

[0223] In some embodiments, the fourth information may be carried in a roaming request confirmation message or a quick roaming notification message.

[0224] Specifically, the aforementioned fourth piece of information may be carried in a roaming request confirmation message (Roaming Ack message) or a quick roaming notification message (FT notify request / resp message). This application is merely an example and does not impose any limitations.

[0225] According to another aspect, embodiments of this application provide a data transmission method during roaming handover, applied to a second access point device (e.g., a current AP MLD). Figure 10 This is the ninth flowchart illustrating a data transmission method during roaming handover proposed in this application embodiment, as shown below. Figure 10 As shown, the data transmission method during the roaming handover process includes step S1001:

[0226] Step S1001: Send the second information to the first access point device; or, send the third information to the non-access point device.

[0227] Wherein, the first access point device is the access point device that the non-access point device switches to from the second access point device during roaming handover, and the second information is used to notify the first access point device that the second downlink data on the second access point device has been sent to the non-access point device, so as to allow the first access point device to send the first downlink data to the non-access point device;

[0228] The third information is used to notify the non-access point device that all or part of the second downlink data on the second access point device has been sent to the non-access point device.

[0229] For the second access point device, the first access point device can be controlled to prohibit or allow the transmission of downlink data in the following two ways:

[0230] 1) Direct control: The second access point device directly controls the first access point device;

[0231] Specifically, the second access point device sends a second message to the first access point device to notify that the second downlink data on the second access point device has been sent to the non-access point device, and to allow the first access point device to send the first downlink data to the non-access point device.

[0232] 2) Indirect control: The second access point device indirectly controls the first access point device through a non-access point device.

[0233] Specifically, the second access point device sends a third message to the non-access point device to notify that all or part of the second downlink data on the second access point device has been sent to the non-access point device, thereby indirectly allowing the first access point device to send the first downlink data to the non-access point device.

[0234] In the embodiments of this application, both of the above control directions can achieve downlink data transmission in the order of "current AP first, then target AP", thereby effectively solving problems such as packet loss, call interruption or video stream stuttering encountered by communication users during roaming handover.

[0235] In some embodiments, prior to the step of sending the second information to the first access point device, the method may further include the following steps:

[0236] Send a first message to the first access point device, the first message being used to prohibit the first access point device from sending the first downlink data stored on the first access point device to the non-access point device;

[0237] Send the second downlink data stored on the second access point device to the non-access point device.

[0238] It should be noted that the process of the second access point device sending its buffered second downlink data to the non-access point device is actually continuous. That is, the action of the second access point device sending the first information to the first access point device should not be interpreted as a trigger condition for sending the second downlink data. The above embodiments only represent the order of their execution. For direct control methods, in some embodiments, the second access point device can be configured to send the first information to the first access point device before the DS Mapping change during roaming handover. This ensures that the first downlink data sent by the first access point device is not sent to the non-access point device before the second downlink data, thus guaranteeing the ordered transmission of downlink data.

[0239] In some embodiments, the first information may indicate the TID corresponding to the second downlink data to prevent the first access point device from sending downlink data in the first downlink data that corresponds to the TID.

[0240] In some embodiments, the second information may indicate one or more TIDs in the TIDs corresponding to the second downlink data to notify the first access point device that all downlink data in the second downlink data corresponding to the one or more TIDs has been sent to the non-access point device, allowing the first access point device to send downlink data in the first downlink data corresponding to the one or more TIDs to the non-access point device.

[0241] Specifically, the first information can indicate the TID corresponding to the second downlink data to prohibit the first access point device from sending downlink data in the first downlink data that corresponds to the aforementioned TID. After the second access point device completes the transmission of part or all of the second downlink data, it can indicate one or more TIDs in the TIDs corresponding to the second downlink data through the second information to notify the first access point device that all downlink data in the second downlink data that corresponds to these one or more TIDs has been sent to the non-access point device. At this time, the first access point device is allowed to send downlink data in the first downlink data that corresponds to these one or more TIDs to the non-access point device, thus ensuring the ordered transmission of downlink data.

[0242] In some embodiments, a specific implementation of sending third information to a non-access point device may include the following steps:

[0243] Send all or part of the second downlink data to the non-access point device;

[0244] The third information is sent to the non-access point device simultaneously with or after all or part of the second downlink data is sent.

[0245] Specifically, regarding the indirect control method, on the one hand, the second access point device sends all or part of the second downlink data to the non-access point device. On the other hand, while sending all or part of the second downlink data, or after sending all or part of the second downlink data, a third message may also be sent to the non-access point device to notify that all or part of the second downlink data on the second access point device has been sent to the non-access point device, thereby indirectly allowing the first access point device to send the first downlink data to the non-access point device.

[0246] In some embodiments, the third information may be carried in the last message of each TID of the second downlink data, wherein the third information is characterized by setting the MoreData subfield carried by the Frame Control field of the MAC frame header of the last message to 0 (also referred to as MD=0).

[0247] In some embodiments, the third information may indicate that all downlink data of one or more TIDs in the TID corresponding to the second downlink data has been sent to the non-access point device.

[0248] Specifically, the aforementioned third information can indicate that all downlink data of one or more TIDs in the TID corresponding to the second downlink data has been sent to the non-access point device. Then, the non-access point device can further allow the first access point device to send the first downlink data corresponding to the aforementioned one or more TIDs to the non-access point device, thus ensuring the ordered transmission of downlink data.

[0249] In some embodiments, the first information and the second information are carried in the context transmission interaction message between the first access point device and the second access point device.

[0250] In some embodiments, prior to the step of sending all or part of the second downlink data to the non-access point device, the method may further include the following steps:

[0251] A fourth message is sent to the non-access point device, the fourth message being used to notify the non-access point device that the second access point device stores second downlink data to be sent to the non-access point device.

[0252] It should be noted that the process of the second access point device sending its cached second downlink data to the non-access point device is actually continuous. That is, the execution action of the second access point device sending the fourth information to the non-access point device should not be understood as a triggering condition. The above embodiment only represents the order of execution of the two.

[0253] In some embodiments, since a non-access point device cannot receive the first downlink data before establishing a new association with the first access point device, as long as the non-access point device establishes an association with the new link according to the fourth information it obtains from the RoamingAck or FT notify Request with the second access point device (including whether it is initially in a power-saving state or some TIDs are in a disabled link state on the new link), it can be guaranteed that the first downlink data sent by the first access point device will not be sent to the non-access point device before the second downlink data, thereby ensuring the ordered transmission of downlink data.

[0254] In some embodiments, the fourth information may further include information for indicating whether the non-access point device performs TTLM negotiation with the first access point device.

[0255] Specifically, the fourth information may include information used to indicate whether the non-access point device should perform TTLM negotiation with the first access point device, which can be divided into the following two cases:

[0256] Case 1: The fourth information includes information used to indicate that the non-access point device supports TTLM negotiation with the first access point device. In this case, the non-access point device can perform TID-level control or link-level control through TTLM negotiation with the first access point device.

[0257] It should be noted that whether a non-access point device supports TTLM negotiation with the first access point device should not be construed as a prerequisite for implementing TID-level or link-level control policies. The above is merely illustrative and is not intended to limit the scope of the application. In other embodiments, even if a non-access point device supports TTLM negotiation with the first access point device, link-level control can still be chosen to leverage the advantage of low overhead.

[0258] Scenario 2: The fourth information includes information indicating that the non-access point device does not support TTLM negotiation with the first access point device. In this case, the non-access point device can perform link-level control over the first access point device.

[0259] In some embodiments, the specific implementation of sending third information to the non-access point device may include:

[0260] After all downlink data corresponding to a TID in the second downlink data has been sent, a third message is sent to the non-access point device, the third message notifying the non-access point device that all downlink data corresponding to the TID has been sent to the non-access point device.

[0261] Specifically, after the second access point device finishes sending all downlink data corresponding to a TID in the second downlink data, it will send a third message to the non-access point device to notify the non-access point device that all downlink data corresponding to a TID has been sent to the non-access point device, so that the non-access point device can perform link-level control or TID-level control on the first access point device based on the information.

[0262] In some embodiments, the fourth information is carried in a roaming request confirmation message or a quick roaming notification message.

[0263] It should be noted that the roaming request confirmation message can be an Ack frame of the roaming request, or it can be called a roaming Ack frame.

[0264] It should also be noted that fast roaming notification messages include, for example, FT notification Request / Response frames.

[0265] In some embodiments, the roaming request confirmation message or quick roaming notification message may include a first field and a second field;

[0266] The first field characterizes the TIDs that the second access point device supports for transmitting downlink data and whether each TID corresponds to downlink data to be sent. The second field is used to indicate whether the non-access point device performs TTLM negotiation with the first access point device.

[0267] It should be noted that each bit in the first field is defined as representing the downlink data buffering status of the specified TID. For example, a bit value of 1 indicates that the corresponding TID has buffered downlink data on the second access point device, and a bit value of 0 indicates that the corresponding TID does not have buffered downlink data on the second access point device. The second field can be set to be represented by 1 bit. For example, a bit value of 1 indicates that the non-access point device should perform TTLM negotiation with the first access point device, and a bit value of 0 indicates that the non-access point device does not perform TTLM negotiation with the first access point device.

[0268] In some embodiments, the fourth information can be carried in the roaming request confirmation message, specifically in the RoamingAck frame. The Roaming Ack frame is a response message returned by the current AP MLD after receiving a roaming request from the non-AP MLD. The information carried in the Roaming Ack frame can be extended to inform the non-AP MLD what cooperation strategy should be adopted during roaming. Specifically, the first and second fields in the aforementioned fourth information can be set by extending the reserved fields included in the subtype field of the RoamingAck frame.

[0269] It should be noted that setting the first and second fields by extending the reserved fields included in the subtype field of the Roaming Ack frame is only one implementation method. The first and second fields can also be added to the frame structure of the original roaming request confirmation message. This application does not limit this.

[0270] Figure 11This is a schematic diagram illustrating the format of a roaming request confirmation message in a data transmission method during roaming handover, as proposed in an embodiment of this application. Figure 11 As shown, the reserved fields of subtype in the dashed box below need to be expanded first.

[0271] The specific format of the Roaming Ack frame can be as follows: Figure 11 As shown, the specific format and meaning of TTLM info are illustrated below. <1> and <2> This can be considered a representation of the first field. <3> and <4> This can be considered a representation of the second field:

[0272] <1> TID_0~TID_7=1 indicates that there is cached data on the current AP MLD corresponding to the DL TID;

[0273] <2> TID_0~TID_7=0 indicates that there is no cached data for the corresponding DL TID on the current AP MLD;

[0274] <3> TTLM negotiation = 1 indicates that when a non-AP MLD establishes an initial link with a target AP MLD, it should perform TTLM negotiation. This can be preset so that TIDs with TID_x = 1 should be negotiated as "disabled Link" and TIDs with TID_x = 0 should be negotiated as "enabled Link".

[0275] <4> TTLM negotiation = 0 indicates that when a non-AP MLD establishes an initial link with a target AP MLD, it should notify the peer that it is in Power Save mode.

[0276] Furthermore, it should be noted that in step 2-a) above, when the non-AP MLD establishes an initial link with the target AP MLD, it needs to negotiate the TTLM state of the corresponding DL TID on the new link according to the DL TID cache state provided by the current AP MLD. When all 8 TIDs have downlink cached data, they need to be negotiated to the "disabled Link" state on the new link. However, there are the following restrictions on the existing TTLM negotiation: when negotiating TTLM, TIDs must not be mapped to a set of links with all zeros, that is, they must be mapped to at least one setup link.

[0277] To address this, in order to support negotiating all DLTIDs to a "disabledLink" state on the new link during roaming handover, an extension is needed to support operational requirements during roaming. Specifically, during roaming handover, it is permissible to temporarily map DLTIDs to a set of links with all zeros, without mapping any setup links.

[0278] In other embodiments, the fourth information may be carried in a fast roaming notification message, specifically in an FT nofity Request frame, which is sent by the current AP MLD to the non-AP MLD. This message can be extended to inform the non-AP MLD what cooperative strategy should be adopted during roaming. Figure 12 This is a schematic diagram illustrating the format of the fast roaming notification message in a data transmission method during roaming handover proposed in an embodiment of this application, as shown below. Figure 12 As shown, the first and second fields in the fourth information above can be set by extending the FT notifyrequest frame body field in the message.

[0279] It should be noted that setting the first and second fields by extending the FT notify request frame body field in the message is only one implementation method. The first and second fields can also be added to the frame structure of the original fast roaming notification message. This application does not limit this.

[0280] Figure 13 This is a schematic diagram of the FT request frame body of the fast roaming notification message in a data transmission method during roaming handover proposed in an embodiment of this application. Figure 13 As shown, the specific format and meaning are illustrated in the following examples. <1> and <2> This can be considered a representation of the first field. <3> and <4> This can be considered a representation of the second field:

[0281] <1> TID_0~TID_7=1 indicates that there is cached data on the current AP MLD corresponding to the DL TID;

[0282] <2> TID_0~TID_7=0 indicates that there is no cached data for the corresponding DL TID on the current AP MLD;

[0283] <3> TTLM negotiation = 1 indicates that when a non-AP MLD establishes an initial link with a target AP MLD, it should perform TTLM negotiation. This can be preset so that TIDs with TID_x = 1 should be negotiated as "disabled Link" and TIDs with TID_x = 0 should be negotiated as "enabled Link".

[0284] <4> TTLM negotiation = 0 indicates that when a non-AP MLD establishes an initial link with a target AP MLD, it should notify the peer that it is in Power Save mode.

[0285] In other embodiments, such as Figure 12 As shown, two FTAction (FT Action) field values ​​can be extended from the reserved values ​​of 5 to 255 to support the FT nofity Request operation of the current AP MLD and the FT nofity Response operation returned by the non-AP MLD, respectively, so as to complete the notification of the current AP MLD to the non-AP MLD control policy and the remaining cache status of DL TID. It should be noted that the specific notification information of the current AP MLD to the non-AP MLD (such as the first and second fields mentioned above) needs to be carried in the FT nofity Request frame for transmission. The FT nofity Response frame is only the response frame of the non-AP MLD to the current AP MLD.

[0286] The following example illustrates the data transmission method during the roaming handover process provided in the embodiments of this application.

[0287] The following problems exist in the related technologies:

[0288] Question 1: How to control the ordered transmission of DL TID data at the link level using a non-AP MLD. This is the main problem that this application needs to solve. The non-AP MLD will only start downlink data transmission to the target AP MLD after receiving all buffered DL TID data from the current AP MLD.

[0289] Question 2: How does the non-AP MLD determine the status of the cached data within the DL TID of the current AP MLD and the transmission strategy? To perform this control, the non-AP MLD needs to know the specific cache status of the current AP MLD's DL TID and the cooperation strategy of the two AP MLDs for each DL TID in order to complete the corresponding operations.

[0290] Question 3: How to achieve ordered transmission at the per-DL TID level? This application can also achieve ordered transmission at the per-DL TID level to meet specific requirements.

[0291] To address the aforementioned problems, this application provides a data transmission method during roaming handover. The following examples illustrate the method provided by this application.

[0292] (I) Example 1: Overall shutdown and activation (link level) of STA downlink transmission in roaming non-AP MLD.

[0293] Figure 14 This is the tenth flowchart illustrating a data transmission method during roaming handover as proposed in this application embodiment. Figure 14 As shown, the specific steps include:

[0294] ① When a non-AP MLD (i.e., the non-AP MLD in the diagram) sends a roaming request message to the current AP MLD (i.e., the current AP MLD in the diagram), the current AP MLD, when establishing an initial new link between the non-AP MLD and the target AP MLD (i.e., the target AP MLD in the diagram), notifies whether TTLM negotiation should be performed and which DL TIDs correspond to cached downlink data. The specific notification method can be through Roaming Ack frames or through FT nofity Request / Response frame sequence exchange.

[0295] ② When the current AP MLD notifies the non-AP MLD not to perform TTLM negotiation, the non-AP MLD can send a reassociation request message to the target AP MLD through non-APSTA2 (i.e., non-AP STA2 in the diagram). The non-AP MLD can then notify the target AP MLD that the non-AP STA2 has entered Power Save mode (i.e., node mode in the diagram) by using the subfield Power Management=1 (i.e., PM=1) carried in the Frame Control field of the frame header. In this way, the target AP MLD will not send downlink TID data of the non-AP MLD through this link.

[0296] ③When the current AP MLD finishes sending the remaining downlink data for a TID, it will notify the non-AP MLD that a DLTID has been sent by setting More Data=0 (i.e., MD=0 in the figure) in the FrameControl field of the data frame header.

[0297] ④ When the non-AP MLD confirms that all the DL TIDs of the downlink data buffered on the current AP MLD have been sent, it will notify the target AP MLD that the non-AP STA2 has entered Active mode (i.e., active mode in the figure) on the new link by sending uplink data or the Power Management field carried in the Frame Control frame header of the management frame with the uplink data sent by the non-AP STA2 being equal to 0; then, the target AP MLD can send new downlink data to the non-AP MLD.

[0298] (II) Example 2: Independent shutdown and activation of downlink TID initiated by STA in roaming non-AP MLD (identifying TID level).

[0299] Figure 15 This is eleventh of the flowcharts illustrating a data transmission method during roaming handover proposed in this application embodiment, as shown below. Figure 15 As shown, the specific steps include:

[0300] ①When a non-AP MLD sends a roaming request message to the current AP MLD, the current AP MLD notifies whether TTLM negotiation should be performed and which DL TIDs have cached downlink data when establishing an initial new link between the non-AP MLD and the target AP MLD. The specific notification method can be through Roaming Ack frames or through FT nofityRequest / Response frames to exchange sequences.

[0301] ② When the current AP MLD notifies the non-AP MLD to perform TTLM negotiation with the target AP MLD, the non-AP MLD will negotiate the DL TID that the current AP MLD has notified and still has downlink cached data to the "disabled Link" state when initially associating with the target AP MLD, through the TID-to-Link Mapping element (i.e., the TTLM element in the figure). The other DL TIDs will be in the "enabled Link" state.

[0302] ③When the current AP MLD finishes sending downlink data for a TID, it will notify the non-AP MLD that a DL TID has been sent by setting More Data=0 in the FrameControl field of the data frame header.

[0303] ④ Whenever the non-AP MLD receives a notification from the current AP MLD that a DL TID has been sent, it will initiate a TTLM renegotiation to put that DL TID into the "enabled Link" state on the new link.

[0304] Steps ③ and ④ above continue until all DL TIDs on the new link in the non-AP MLD enter the "enabled Link" state.

[0305] (III) Example 3: Independent shutdown and activation of downlink TID initiated by target AP MLD.

[0306] Figure 16 This is the twelfth flowchart illustrating a data transmission method during roaming handover as proposed in this application embodiment. Figure 16 As shown, the specific steps include:

[0307] ①After the non-AP MLD sends a roaming request message to the current AP MLD, the current AP MLD and the target AP MLD negotiate to complete the DL TID level control through the target AP MLD. The current AP MLD will notify the target AP MLD which DL TIDs have buffered data to be sent through the context transfer exchange sequence. Correspondingly, if the target AP MLD has new received data, the target AP MLD will first suspend sending new received data to the non-AP MLD.

[0308] ②The remaining downlink data on the current AP MLD is transmitted via the original non-AP STA1.

[0309] ③After the current AP MLD completes the transmission of downlink data for a TID, it will carry a notification that the transmission of DL TID buffer data for a non-AP MLD has been completed in the context transfer information sent to the target AP MLD.

[0310] ④Whenever the target AP MLD receives a notification of the TID status in step ③, it will restart the transmission operation of the corresponding DL TID on the roaming link.

[0311] Steps ③ and ④ above continue until all DL TIDs on the new link in the non-AP MLD enter the "enabled Link" state.

[0312] In this embodiment of the application, a method for determining and implementing different levels of ordered data transmission is given when a non-AP MLD roams between two AP MLDs;

[0313] 1) A method is proposed in which, during roaming, the non-AP MLD notifies the target AP MLD that the roaming non-AP MLD has entered different Power Save states by controlling the Power Management sub-field carried in the Frame Control field of the data frame or management frame sent to the target AP MLD, so as to realize the ordered transmission of DL data at the entire link level and solve the aforementioned problem 1.

[0314] 2) A method is proposed that during roaming, the current AP MLD and the non-AP MLD communicate with each DL TID of the current AP MLD through Roaming Ack or FT notify Request / Response to notify each DL TID of the current AP MLD whether there is cached data to be sent and the corresponding cooperative sending strategy, which solves the aforementioned problem 2.

[0315] 3) A method for ensuring data order transmission at the DL TID level is proposed during roaming by negotiating downlink TID-to-Link Mapping between the non-AP MLD and the target AP MLD, thus solving the aforementioned problem 3.

[0316] 4) A method is proposed in which the target AP MLD synchronizes the completion status of its cached DL TID transmission with the current AP MLD during roaming, and then starts downlink transmission of the corresponding TID accordingly, thereby realizing the order-preserving transmission of DL data at the TID level, which also solves the aforementioned problem 3.

[0317] It should be noted that the above examples are only for understanding this application and do not constitute a limitation on the data transmission method in the roaming handover process of this application. Any simple modifications based on this technical concept are within the protection scope of this application.

[0318] This application also provides a data transmission device during roaming handover, applied to a first access point device. Figure 17 This is one of the structural schematic diagrams of a data transmission device during roaming handover proposed in an embodiment of this application, such as... Figure 17 As shown, the data transmission device during the roaming handover process includes:

[0319] The acquisition module 1701 is used to acquire first downlink data to be sent to a non-access point device; wherein the first access point device is the access point device that the non-access point device switches to from the second access point device during roaming handover.

[0320] The first sending module 1702 is configured to send the first downlink data to the non-access point device only after receiving the second information; wherein the second information is used to notify the first access point device that the second downlink data on the second access point device has been sent to the non-access point device, and to allow the first access point device to send the first downlink data to the non-access point device.

[0321] The data transmission device for roaming handover provided in this application adopts the data transmission method for roaming handover on the first access point device side in the above embodiments. The implementation details of any of the above embodiments can be referenced to solve the corresponding technical problems. Compared with the prior art, the beneficial effects of the data transmission device for roaming handover provided in this application are the same as those of the data transmission method for roaming handover provided in the above embodiments, and other technical features in the data transmission device for roaming handover are the same as those disclosed in the methods of the above embodiments, and will not be repeated here.

[0322] This application also provides a data transmission device during roaming handover, applicable to non-access point equipment. Figure 18 This is a second schematic diagram of a data transmission device during roaming handover, as proposed in an embodiment of this application. Figure 18 As shown, the data transmission device during the roaming handover process includes:

[0323] The receiving module 1801 is configured to receive third information from the second access point device, the third information being used to notify the non-access point device that all or part of the second downlink data on the second access point device has been sent to the non-access point device.

[0324] The second sending module 1802 is configured to send second information to the first access point device in response to the third information. The second information is used to notify the first access point device that all or part of the second downlink data on the second access point device has been sent to the non-access point device, and to allow the first access point device to send all or part of the first downlink data on the first access point device to the non-access point device.

[0325] Wherein, the first access point device is the access point device that the non-access point device switches to from the second access point device during roaming handover.

[0326] The data transmission device for roaming handover provided in this application adopts the data transmission method for roaming handover on the non-access point device side in the above embodiments. The implementation details of any of the above embodiments can be referenced to solve the corresponding technical problems. Compared with the prior art, the beneficial effects of the data transmission device for roaming handover provided in this application are the same as those of the data transmission method for roaming handover provided in the above embodiments, and other technical features in the data transmission device for roaming handover are the same as those disclosed in the methods of the above embodiments, and will not be repeated here.

[0327] This application also provides a data transmission device during roaming handover, applied to a second access point device. Figure 19 This is the third schematic diagram of a data transmission device during roaming handover, as proposed in the embodiments of this application. Figure 19 As shown, the data transmission device during the roaming handover process includes:

[0328] The third transmitting module 1901 is used for:

[0329] Send a second message to a first access point device; wherein the first access point device is the access point device that the non-access point device switches to from the second access point device during roaming handover, and the second message is used to notify the first access point device that the second downlink data on the second access point device has been sent to the non-access point device, and to allow the first access point device to send the first downlink data to the non-access point device;

[0330] Alternatively, a third message may be sent to the non-access point device; wherein the third message is used to notify the non-access point device that all or part of the second downlink data on the second access point device has been sent to the non-access point device.

[0331] The data transmission device for roaming handover provided in this application adopts the data transmission method for roaming handover on the second access point device side in the above embodiments. The implementation details of any of the above embodiments can be referenced to solve the corresponding technical problems. Compared with the prior art, the beneficial effects of the data transmission device for roaming handover provided in this application are the same as those of the data transmission method for roaming handover provided in the above embodiments, and other technical features in the data transmission device for roaming handover are the same as those disclosed in the methods of the above embodiments, and will not be repeated here.

[0332] This application provides a data transmission device, which includes: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, which are executed by the at least one processor to enable the at least one processor to perform the data transmission method in the roaming handover process described in the above embodiments.

[0333] The following is for reference. Figure 20 , Figure 20 This is a schematic diagram of a data transmission device according to an embodiment of this application, illustrating a structure suitable for implementing the data transmission device of this application. The data transmission device in this application may include, but is not limited to, mobile terminals such as mobile phones, laptops, digital broadcast receivers, PDAs (Personal Digital Assistants), PADs (Portable Application Description), PMPs (Portable Media Players), in-vehicle terminals (e.g., in-vehicle navigation terminals), and fixed terminals such as digital TVs and desktop computers. Figure 20 The data transmission device shown is merely an example and should not impose any limitations on the functionality and scope of use of the embodiments of this application.

[0334] like Figure 20As shown, the data transmission device may include a processing unit 2001 (e.g., a central processing unit, a graphics processing unit, etc.), which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 2002 or a program loaded from a storage device 2003 into a random access memory (RAM) 2004. The RAM 2004 also stores various programs and data required for the operation of the data transmission device. The processing unit 2001, ROM 2002, and RAM 2004 are interconnected via a bus 2005. An input / output (I / O) interface 2006 is also connected to the bus. Typically, the following systems can be connected to the I / O interface 2006: input devices 2007 including, for example, touchscreens, touchpads, keyboards, mice, image sensors, microphones, accelerometers, gyroscopes, etc.; output devices 2008 including, for example, liquid crystal displays (LCDs), speakers, vibrators, etc.; storage devices 2003 including, for example, magnetic tapes, hard disks, etc.; and communication devices 2009. Communication device 2009 allows data transmission equipment to communicate wirelessly or wiredly with other devices to exchange data. Although data transmission equipment with various systems is shown in the figure, it should be understood that implementation or possession of all the systems shown is not required. More or fewer systems may be implemented alternatively.

[0335] Specifically, according to the embodiments disclosed in this application, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments disclosed in this application include a computer program product comprising a computer program carried on a computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via a communication device, or installed from storage device 2003, or installed from ROM 2002. When the computer program is executed by processing device 2001, it performs the functions defined in the methods of the embodiments disclosed in this application.

[0336] The data transmission device provided in this application, employing the data transmission method during the roaming handover process described in the above embodiments, can solve the corresponding technical problems. Compared with the prior art, the beneficial effects of the data transmission device provided in this application are the same as those of the data transmission method during the roaming handover process provided in the above embodiments, and other technical features of this data transmission device are the same as those disclosed in the method of the previous embodiment, and will not be repeated here.

[0337] It should be understood that the various parts disclosed in this application can be implemented using hardware, software, firmware, or a combination thereof. In the description of the above embodiments, specific features, structures, materials, or characteristics can be combined in any suitable manner in one or more embodiments or examples.

[0338] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

[0339] This application provides a computer-readable storage medium having computer-readable program instructions (i.e., a computer program) stored thereon, the computer-readable program instructions being used to execute the data transmission method during the roaming handover process in the above embodiments.

[0340] The computer-readable storage medium provided in this application may be, for example, a USB flash drive, but is not limited to, electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices, or any combination thereof. More specific examples of computer-readable storage media may include, but are not limited to: electrical connections having one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof. In this embodiment, the computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, system, or device. The program code contained on the computer-readable storage medium may be transmitted using any suitable medium, including but not limited to: wires, optical cables, RF (Radio Frequency), etc., or any suitable combination thereof.

[0341] According to one embodiment, the computer-readable storage medium is non-volatile or non-transient.

[0342] The aforementioned computer-readable storage medium may be included in a data transmission device or may exist independently without being assembled into a data transmission device.

[0343] The aforementioned computer-readable storage medium carries one or more programs, which, when executed by a data transmission device, cause the data transmission device to perform the following steps:

[0344] Acquire the first downlink data to be sent to the non-access point device; wherein, the first access point device is the access point device that the non-access point device switches to from the second access point device during roaming handover;

[0345] The first downlink data is sent to the non-access point device only after receiving the second information; wherein, the second information is used to notify the first access point device that the second downlink data on the second access point device has been sent to the non-access point device, and to allow the first access point device to send the first downlink data to the non-access point device.

[0346] Computer program code for performing the operations of this application can be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, and C++, and conventional procedural programming languages ​​such as the "C" language or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving remote computers, the remote computer can be connected to the user's computer via any type of network—including a Local Area Network (LAN) or a Wide Area Network (WAN)—or can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0347] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of this application. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0348] The modules described in the embodiments of this application can be implemented in software or hardware. The names of the modules do not necessarily limit the functionality of the unit itself.

[0349] The readable storage medium provided in this application is a computer-readable storage medium that stores computer-readable program instructions (i.e., a computer program) for executing the data transmission method during the roaming handover process described above, thereby solving the corresponding technical problem. Compared with the prior art, the beneficial effects of the computer-readable storage medium provided in this application are the same as the beneficial effects of the data transmission method during the roaming handover process provided in the above embodiments, and will not be repeated here.

[0350] This application also provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the data transmission method during the roaming handover process as described above.

[0351] The computer program product provided in this application can solve the technical problems corresponding to the data transmission method in the roaming handover process described above. Compared with the prior art, the beneficial effects of the computer program product provided in this application are the same as the beneficial effects of the data transmission method in the roaming handover process provided in the above embodiments, and will not be repeated here.

[0352] The above description is only a part of the embodiments of this application and does not limit the patent scope of this application. All equivalent structural transformations made under the technical concept of this application and using the contents of the specification and drawings of this application, or direct / indirect applications in other related technical fields, are included in the patent protection scope of this application.

Claims

1. A data transmission method during roaming handover, characterized in that, Applied to a first access point device, the method includes: Acquire the first downlink data to be sent to the non-access point device; wherein, the first access point device is the access point device that the non-access point device switches to from the second access point device during roaming handover; The first downlink data is sent to the non-access point device only after receiving the second information; wherein, the second information is used to notify the first access point device that the second downlink data on the second access point device has been sent to the non-access point device, and to allow the first access point device to send the first downlink data to the non-access point device.

2. The data transmission method as described in claim 1, characterized in that, Before receiving the second information, the method further includes: Receive first information, the first information being used to prohibit the first access point device from sending the first downlink data to the non-access point device; In response to the first information, the transmission of the first downlink data to the non-access point device is prohibited.

3. The data transmission method as described in claim 2, characterized in that, The receiving of the first information includes: Receive first information from the non-access point device; wherein the first information is used to notify the first access point device that the power management state of the non-access point device is in power-saving mode.

4. The data transmission method as described in claim 1 or 3, characterized in that, The step of sending the first downlink data to the non-access point device only after receiving the second information includes: Receive second information from the non-access point device; wherein the second information is used to notify the first access point device that the power management state of the non-access point device has been switched to active mode; The first downlink data is sent to the non-access point device only in response to the second information.

5. The data transmission method as described in claim 4, characterized in that, The second information is sent by the non-access point device in response to the fact that all the second downlink data on the second access point device has been sent to the non-access point device.

6. The data transmission method as described in claim 3, characterized in that, The step of prohibiting the transmission of the first downlink data to the non-access point device in response to the first information includes: In response to the first information, the transmission of downlink data corresponding to all TIDs in the first downlink data to the non-access point device is prohibited.

7. The data transmission method as described in claim 4, characterized in that, The response to the second information to send the first downlink data to the non-access point device includes: In response to the second information, downlink data corresponding to all TIDs in the first downlink data is sent to the non-access point device.

8. The data transmission method as described in claim 2, characterized in that, The receiving of the first information includes: Receive first information from the non-access point device; wherein the first information indicates one or more TIDs corresponding to the second downlink data, and is used to notify the first access point device to set the one or more TIDs to a link disabled state, so as to prohibit the transmission of downlink data in the first downlink data corresponding to the one or more TIDs; The step of prohibiting the transmission of the first downlink data to the non-access point device in response to the first information includes: In response to the first information, the one or more TIDs are set to a link disabled state.

9. The data transmission method as described in claim 1 or 8, characterized in that, The step of sending the first downlink data to the non-access point device only after receiving the second information includes: Receive second information from the non-access point device; wherein the second information indicates one or more TIDs corresponding to the downlink data that has been sent to the non-access point device in the second downlink data, and is used to notify the first access point device to set the one or more TIDs to the link enabled state; In response to the second information, the one or more TIDs indicated by the second information are set to the link enabled state; The downlink data in the first downlink data corresponding to the one or more TIDs indicated by the second information is sent to the non-access point device.

10. The data transmission method as described in claim 9, characterized in that, The first information and the second information are carried in the TTLM negotiation message between the non-access point device and the first access point device.

11. The data transmission method as described in claim 2, characterized in that, The receiving of the first information includes: Receive first information from the second access point device; wherein the first information indicates one or more TIDs corresponding to the second downlink data.

12. The data transmission method as described in claim 1 or 11, characterized in that, Only after receiving the second information is the first downlink data sent to the non-access point device, including: Receive second information from the second access point device; wherein the second information indicates the TID corresponding to the downlink data in the second downlink data that has been sent to the non-access point device; In response to the second information, the downlink data corresponding to the TID indicated by the second information in the first downlink data is sent to the non-access point device.

13. The data transmission method as described in claim 12, characterized in that, The first information and the second information are carried in the context transmission interaction message between the first access point device and the second access point device.

14. The data transmission method according to any one of claims 6 to 8, characterized in that, The TID is the downlink TID.

15. A data transmission method during roaming handover, characterized in that, Applied to non-access point devices, the method includes: Receive third information from the second access point device, the third information being used to notify the non-access point device that all or part of the second downlink data on the second access point device has been sent to the non-access point device; In response to the third information, a second information is sent to the first access point device, the second information being used to notify the first access point device that all or part of the second downlink data on the second access point device has been sent to the non-access point device, and to allow the first access point device to send all or part of the first downlink data on the first access point device to the non-access point device; Wherein, the first access point device is the access point device that the non-access point device switches to from the second access point device during roaming handover.

16. The data transmission method as described in claim 15, characterized in that, Before receiving the third information from the second access point device, the method further includes: The device receives fourth information from the second access point device, the fourth information being used to notify the non-access point device that the second access point device holds second downlink data to be sent to the non-access point device; In response to the fourth information, a first information is sent to the first access point device, the first information being used to prohibit the first access point device from sending the first downlink data to the non-access point device.

17. The data transmission method as described in claim 16, characterized in that, The first information is used to notify the first access point device that the power management state of the non-access point device is in power-saving mode, thereby prohibiting the first access point device from sending the first downlink data to the non-access point device.

18. The data transmission method as described in claim 15 or 17, characterized in that, The step of sending second information to the first access point device in response to the third information includes: In response to the third information indicating that all of the second downlink data on the second access point device has been sent to the non-access point device, a second information is sent to the first access point device, wherein the second information is used to notify the first access point device that the power management state of the non-access point device has been switched to active mode, thereby allowing the first access point device to send the first downlink data to the non-access point device.

19. The data transmission method as described in claim 16, characterized in that, The fourth information also includes information for instructing the non-access point device not to perform TTLM negotiation with the first access point device.

20. The data transmission method as described in claim 16, characterized in that, The fourth information also includes information for indicating the TID corresponding to the second downlink data.

21. The data transmission method as described in claim 16, characterized in that, The first information indicates one or more TIDs corresponding to the second downlink data and is used to notify the first access point device to set the one or more TIDs to a link disabled state so as to prohibit the transmission of downlink data in the first downlink data corresponding to the one or more TIDs.

22. The data transmission method as described in claim 15 or 21, characterized in that, The step of sending second information to the first access point device in response to the third information includes: In response to the third information indicating that all downlink data corresponding to one or more TIDs of the TIDs corresponding to the second downlink data has been sent to the non-access point device, the second information is sent to the first access point device; The second information indicates the one or more TIDs and notifies the first access point device to set the one or more TIDs to a link-enabled state, so that the first access point device can send downlink data corresponding to the one or more TIDs in the first downlink data to the non-access point device.

23. The data transmission method as described in claim 22, characterized in that, The first information and the second information are carried in the TTLM negotiation message between the non-access point device and the first access point device.

24. The data transmission method as described in claim 16, characterized in that, Before receiving the fourth information from the second access point device, the method further includes: Send a roaming request message to the second access point device; wherein the roaming request message requests that the non-access point device be switched from the second access point device to the first access point device during roaming handover.

25. The data transmission method as described in claim 16, characterized in that, The fourth information also includes information for instructing the non-access point device to perform TTLM negotiation with the first access point device.

26. The data transmission method as described in claim 20 or 21, characterized in that, The TID is the downlink TID.

27. The data transmission method according to any one of claims 16, 17, 19 to 21, 25, characterized in that, The fourth piece of information is carried in the roaming request confirmation message or the quick roaming notification message.

28. A data transmission method during roaming handover, characterized in that, Applied to a second access point device, the method includes: Send a second message to a first access point device; wherein the first access point device is the access point device that the non-access point device switches to from the second access point device during roaming handover, and the second message is used to notify the first access point device that the second downlink data on the second access point device has been sent to the non-access point device, so as to allow the first access point device to send the first downlink data to the non-access point device; Alternatively, a third message may be sent to the non-access point device; wherein the third message is used to notify the non-access point device that all or part of the second downlink data on the second access point device has been sent to the non-access point device.

29. The data transmission method as described in claim 28, characterized in that, Before sending the second information to the first access point device, the method further includes: Send a first message to the first access point device, the first message being used to prohibit the first access point device from sending the first downlink data stored on the first access point device to the non-access point device; Send the second downlink data stored on the second access point device to the non-access point device.

30. The data transmission method as described in claim 29, characterized in that, The first information indicates the TID corresponding to the second downlink data, so as to prevent the first access point device from sending downlink data in the first downlink data that corresponds to the TID.

31. The data transmission method as described in claim 28 or 30, characterized in that, The second information indicates one or more TIDs in the TIDs corresponding to the second downlink data, to notify the first access point device that all downlink data in the second downlink data corresponding to the one or more TIDs has been sent to the non-access point device, allowing the first access point device to send downlink data in the first downlink data corresponding to the one or more TIDs to the non-access point device.

32. The data transmission method as described in claim 28, characterized in that, Sending third information to non-access point devices includes: Send all or part of the second downlink data to the non-access point device; The third information is sent to the non-access point device simultaneously with or after all or part of the second downlink data is sent.

33. The data transmission method as described in claim 32, characterized in that, The third information is carried in the last message of each TID of the second downlink data, wherein the third information is represented by setting the MoreData subfield carried in the control frame field of the MAC frame header of the last message to 0.

34. The data transmission method as described in claim 28 or 32, characterized in that, The third information indicates that all downlink data of one or more TIDs corresponding to the second downlink data has been sent to the non-access point device.

35. The data transmission method as described in claim 28, characterized in that, The first information and the second information are carried in the context transmission interaction message between the first access point device and the second access point device.

36. The data transmission method as described in claim 32, characterized in that, Before sending all or part of the second downlink data to the non-access point device, the method further includes: A fourth message is sent to the non-access point device, the fourth message being used to notify the non-access point device that the second access point device stores second downlink data to be sent to the non-access point device.

37. The data transmission method as described in claim 36, characterized in that, The fourth information also includes information for indicating whether the non-access point device performs TTLM negotiation with the first access point device.

38. The data transmission method as described in claim 28, characterized in that, Sending third information to non-access point devices includes: After all downlink data corresponding to a TID in the second downlink data has been sent, a third message is sent to the non-access point device, the third message notifying the non-access point device that all downlink data corresponding to the TID has been sent to the non-access point device.

39. The data transmission method as described in claim 36 or 37, characterized in that, The fourth piece of information is carried in the roaming request confirmation message or the quick roaming notification message.

40. The data transmission method as described in claim 39, characterized in that, The roaming request confirmation message or quick roaming notification message includes a first field and a second field; The first field characterizes the TIDs that the second access point device supports for transmitting downlink data and whether each TID corresponds to downlink data to be sent. The second field is used to indicate whether the non-access point device performs TTLM negotiation with the first access point device.

41. A data transmission device, characterized in that, The device includes: a memory, a processor, and a computer program stored in the memory and executable on the processor, the computer program being configured to implement the steps of the data transmission method as described in any one of claims 1 to 14, or the data transmission method as described in any one of claims 15 to 27, or the data transmission method as described in any one of claims 28 to 40.

42. A storage medium, characterized in that, The storage medium is a computer-readable storage medium, and a computer program is stored on the storage medium. When the computer program is executed by a processor, it implements the steps of the data transmission method as described in any one of claims 1 to 14, or the data transmission method as described in any one of claims 15 to 27, or the data transmission method as described in any one of claims 28 to 40.

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