WO2025199767A1 - Multi-link device roaming-based communication method, multi-link device roaming-based context migration method, multi-link device roaming-based information conversion method and wireless communication device - Google Patents

Abstract

Provided in the embodiments of the present application are a multi-link device roaming-based communication method, a multi-link device roaming-based context migration method, a multi-link device roaming-based information conversion method and a wireless communication device. The multi-link device roaming-based communication method is executed on a non-access point multi-link device (non-AP MLD), and comprises: a non-AP MLD establishing a multi-link connection with a first access point multi-link device (AP MLD 1); the non-AP MLD initiating a roaming request to the AP MLD 1 or a second access point multi-link device (AP MLD 2); and after roaming is completed, the non-AP MLD establishing a multi-link connection with the AP MLD 2.

Description

Communication method, context migration method, information conversion method, and wireless communication device based on multi-link device roaming Technical Field

Embodiments of the present application relate to the field of mobile communication technologies, and in particular to a communication method, a context migration method, an information conversion method, and a wireless communication device based on multi-link device roaming.

Background Art

In the Institute of Electrical and Electronics Engineers (IEEE) Wireless Fidelity 7 (Wi-Fi 7) and earlier Wi-Fi standards, a station (STA, including non-AP Multi-Link Devices (MLDs)) roaming from one access point (AP) Multi-Link Device (MLD) to another must first disconnect from the old AP MLD and then reassociate with the new one. During this process, the STA (or non-AP MLD) experiences a significant interruption, potentially impacting the efficiency and quality of wireless communications.

Summary of the Invention

Embodiments of the present application provide a communication method, a context migration method, an information conversion method, and a wireless communication device based on multi-link device roaming to improve the problems of the prior art and other problems.

An embodiment of the present application provides a communication method based on multi-link device roaming, which is executed on a non-access point multi-link device non-AP MLD, wherein the communication method includes: the non-AP MLD establishes a multi-link connection with a first access point multi-link device AP MLD 1; the non-AP MLD requests roaming from the AP MLD 1 or the second access point multi-link device AP MLD 2; and after roaming is completed, the non-AP MLD establishes a multi-link connection with the AP MLD 2.

Through the above technical solution, the non-AP MLD requests roaming from the AP MLD 1 or AP MLD 2, and after roaming is completed, the non-AP MLD establishes a multi-link connection with the AP MLD 2, thereby improving the experience of the non-AP MLD when roaming on the AP MLD 2 and achieving basically uninterrupted roaming.

An embodiment of the present application provides a communication method based on multi-link device roaming, which is executed on an access point multi-link device AP MLD, wherein the communication method includes: a first access point multi-link device AP MLD 1 sends a first link reconfiguration frame to a non-access point multi-link device non-AP MLD to initiate a roaming operation, wherein the first link reconfiguration frame is used to request the non-AP MLD to roam from the AP MLD 1 to the second access point multi-link device AP MLD 2; and the AP MLD 1 receives a second link reconfiguration frame sent by the non-AP MLD to obtain a roaming result.

Through the above technical solution, the AP MLD 1 sends a first link reconfiguration frame to the non-AP MLD to initiate roaming, and the AP MLD 1 receives a second link reconfiguration frame sent by the non-AP MLD to obtain the roaming result, thereby improving the experience of the non-AP MLD when roaming with the AP MLD 2 and achieving basically uninterrupted roaming.

An embodiment of the present application provides a communication method based on multi-link device roaming, which is executed on an access point multi-link device AP MLD, wherein the communication method includes: the second access point multi-link device AP MLD 2 sends a first link reconfiguration frame to the non-access point multi-link device non-AP MLD to initiate a roaming operation, wherein the first link reconfiguration frame is used to request the non-AP MLD to roam from the first access point multi-link device AP MLD 1 to the AP MLD 2; and the AP MLD 2 receives the second link reconfiguration frame sent by the non-AP MLD to obtain a roaming result.

Through the above technical solution, the AP MLD 2 sends a first link reconfiguration frame to the non-AP MLD to initiate roaming, and the AP MLD 2 receives a second link reconfiguration frame sent by the non-AP MLD to obtain the roaming result, thereby improving the experience of the non-AP MLD when roaming on the AP MLD 2 and achieving basically uninterrupted roaming.

An embodiment of the present application provides a context migration method based on multi-link device roaming, which is executed on an access point multi-link device AP MLD, wherein the context migration method includes: a first access point multi-link device AP MLD 1 establishes a backhaul link with a second access point multi-link device AP MLD 2; the AP MLD 1 exchanges context migration information with the AP MLD 2 through the backhaul link.

Through the above technical solution, the AP MLD 1 exchanges context migration information with the AP MLD 2 via the backhaul link. This improves the experience of the non-AP MLD when roaming to the AP MLD 2, achieving essentially uninterrupted roaming. It also allows the AP MLD 2 to reserve data and configure communications for the non-AP MLD in advance, further reducing roaming delay.

An embodiment of the present application provides an information conversion method based on multi-link device roaming, which is executed on a non-access point multi-link device non-AP MLD, wherein the information conversion method includes: when the non-AP MLD roams between a first access point multi-link device AP MLD 1 and a second access point multi-link device AP MLD 2, converting information between the non-AP MLD and the AP MLD 1 to adapt to the communication between the non-AP MLD and the AP MLD 2.

Through the above technical solution, the AP MLD 1 converts the information between the non-AP MLD and the AP MLD 1 to adapt to the communication between the non-AP MLD and the AP MLD 2, thereby improving the experience of the non-AP MLD when roaming on the AP MLD 2, achieving basically uninterrupted roaming, facilitating the non-AP MLD and the AP MLD 2 to communicate normally as soon as possible, and shortening the roaming delay.

An embodiment of the present application provides a communication method based on multi-link device roaming, which is executed on a non-access point multi-link device non-AP MLD, wherein the communication method includes: after the non-AP MLD roams from a first access point multi-link device AP MLD 1 to a second access point multi-link device AP MLD 2, the non-AP MLD confirms the roaming result.

Through the above technical solution, the non-AP MLD confirms the roaming result, thereby improving the experience of the non-AP MLD when roaming the AP MLD 2 and achieving basically uninterrupted roaming. The confirmation operation performed by the non-AP MLD after the roaming is completed can ensure that the newly established link of the non-AP MLD after roaming the AP MLD 2 works normally.

An embodiment of the present application provides a communication method based on multi-link device roaming, which is executed on an access point multi-link device AP MLD, wherein the communication method includes: after a non-access point multi-link device non-AP MLD roams from a first access point multi-link device AP MLD 1 to a second access point multi-link device AP MLD 2, the AP MLD 2 confirms the roaming result.

Through the above technical solution, the AP MLD 2 confirms the roaming result, thereby improving the experience of the non-AP MLD when roaming on the AP MLD 2 and achieving basically uninterrupted roaming. The confirmation operation performed by the AP MLD 2 after the roaming is completed can ensure that the newly established link of the non-AP MLD after roaming on the AP MLD 2 works normally.

A wireless communication device provided in an embodiment of the present application includes: a processor and a memory, the memory being used to store a computer program, the processor being used to call and run the computer program stored in the memory to execute the above-mentioned relay communication method.

The relay communication device provided in the embodiment of the present application includes a processor and a memory. The memory is used to store a computer program, and the processor is used to call and run the computer program stored in the memory to perform the above-mentioned relay communication method.

The first node provided in an embodiment of the present application includes a processor and a memory. The memory is used to store a computer program, and the processor is used to call and run the computer program stored in the memory to perform the above-mentioned relay communication method.

The chip provided in the embodiment of the present application is used to implement the above-mentioned relay communication method.

Specifically, the chip includes: a processor for calling and running a computer program from a memory, so that a device equipped with the chip executes the above-mentioned relay communication method.

The computer-readable storage medium provided in an embodiment of the present application is used to store a computer program, which enables a computer to execute the above-mentioned relay communication method.

The computer program product provided in an embodiment of the present application includes computer program instructions, which enable a computer to execute the above-mentioned relay communication method.

The computer program provided in the embodiment of the present application, when executed on a computer, enables the computer to execute the above-mentioned method for relay communication.

Through the above technical solution, the experience of the non-AP MLD roaming the AP MLD 2 is improved, and basically uninterrupted roaming is achieved.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

Figure 1A is a schematic diagram of establishing multi-links between an access point multi-link device (AP MLD) and a non-access point multi-link device (non-AP MLD) in the IEEE 802.11be standard;

Figure 1B is a schematic diagram showing non-AP MLD 1 maintaining multiple links with AP MLD 1 and AP MLD 2.

FIG1C is a schematic diagram of non-AP MLD 1 switching from AP MLD 1 to AP MLD 2 according to an embodiment of the present application;

FIG2A is a schematic flow chart of a communication method based on multi-link device roaming according to an embodiment of the present application;

FIG2B is a schematic diagram of several methods for non-AP MLD to initiate roaming according to an embodiment of the present application;

FIG2C is a schematic diagram of the format of the presence bit map subfield of a reconfigured multilink element according to an embodiment of the present application;

FIG2D is a schematic diagram of a general information field format of a reconfigured multilink element provided in an embodiment of the present application;

FIG2E is a schematic diagram of the format of a per-site summary sub-element of a reconfiguration multilink element according to an embodiment of the present application;

FIG2F is a schematic diagram of the STA control field format of the reconfiguration multilink element provided in an embodiment of the present application;

FIG2G is a schematic diagram of the STA control field format of the reconfiguration multilink element provided in an embodiment of the present application;

FIG2H is a schematic diagram of a new link ID information field in a STA information field format according to an embodiment of the present application;

FIG2I is a schematic diagram of a dual subfield format of a reconfiguration status according to an embodiment of the present application;

FIG2J is a schematic diagram of the format of the presence bitmap subfield provided in an embodiment of the present application;

FIG2K is a schematic diagram of the format of the general information field of the basic multilink element provided in an embodiment of the present application;

FIG2L is a schematic diagram of the format of a per-site summary sub-element provided in an embodiment of the present application;

FIG2M is a schematic diagram of the format of the STA Control field of the Basic Multilink Element provided in an embodiment of the present application;

FIG2N is a schematic diagram of the format of the STA Control field of the Basic Multilink Element provided in an embodiment of the present application;

FIG3A is a flow chart of a communication method based on multi-link device roaming according to an embodiment of the present application;

FIG3B is a flow chart of a communication method based on multi-link device roaming according to an embodiment of the present application;

FIG4A is a flow chart of a communication method based on multi-link device roaming according to an embodiment of the present application;

FIG4B is a flow chart of a communication method based on multi-link device roaming according to an embodiment of the present application;

FIG5A is a flow chart of a communication method based on a context migration method for multi-link device roaming according to an embodiment of the present application;

FIG5B is a flow chart of a communication method based on a context migration method for multi-link device roaming according to an embodiment of the present application;

FIG5C is a flow chart of a communication method based on a context migration method for multi-link device roaming according to an embodiment of the present application;

FIG5D is a flow chart of a communication method based on a context migration method for multi-link device roaming according to an embodiment of the present application;

FIG6 is a flow chart of an information conversion method based on multi-link device roaming according to an embodiment of the present application;

FIG7A is a flow chart of a communication method based on multi-link device roaming according to an embodiment of the present application;

FIG7B is a flow chart of a communication method based on multi-link device roaming according to an embodiment of the present application;

FIG8A is a flow chart of a communication method based on multi-link device roaming according to an embodiment of the present application;

FIG8B is a flow chart of a communication method based on multi-link device roaming according to an embodiment of the present application;

FIG9A is a schematic diagram of the format of a roaming confirmation frame provided in an embodiment of the present application;

FIG9B is a schematic diagram of the format of a roaming completion frame provided in an embodiment of the present application;

FIG10 is a schematic structural diagram of a wireless communication device provided in an embodiment of the present application;

FIG11 is a schematic structural diagram of a chip according to an embodiment of the present application;

FIG12 is a schematic block diagram of a wireless communication system provided in an embodiment of the present application.

DETAILED DESCRIPTION

The following will describe the technical solutions in the embodiments of this application in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

It should be understood that the term "and/or" in this document simply describes a relationship between related objects, indicating that three possible relationships exist. For example, "A and/or B" can represent: A exists alone, A and B exist simultaneously, or B exists alone. Furthermore, the character "/" in this document generally indicates that the related objects are in an "or" relationship.

For ease of understanding, Table 1 provides the definitions of the main abbreviations involved in this application.

Table 1: Abbreviations

In the Wi-Fi 7 standard based on IEEE 802.11be, an AP can be an (EHT)AP MLD with multiple subordinate APs. As shown in Figure 1, AP MLD 1 has three subordinate APs: AP 1, AP 2, and AP 3. A STA can be a non-AP MLD with multiple subordinate non-AP STAs. As shown in Figure 1, non-AP MLD 1 has three subordinate non-AP STAs: non-AP STA 1, non-AP STA 2, and non-AP STA 3. Non-AP MLD 1 can establish multiple links with multiple subordinate APs of (EHT)AP MLD 1 through its multiple subordinate non-AP STAs, such as Link 1, Link 2, and Link 3 (see Figure 1). However, if non-AP MLD 1 wants to switch to another AP MLD, it needs to disconnect all links with the current (EHT) AP MLD 1, cancel the authentication and/or association status, and then re-authenticate and/or associate with the new AP MLD and re-establish multiple links.

During the Wi-Fi 8 standardization process, it was proposed that a non-AP MLD can maintain State 4 with the new AP MLD when switching to an AP MLD. This means that the non-AP MLD does not need to re-authenticate and/or associate with the new AP MLD. As shown in Figure 1B, during a handover from (EHT)AP MLD 1 to (EHT)AP MLD 2 in a mobile scenario, non-AP MLD 1 can establish Link 2 and Link 3 with (EHT)AP MLD 2 while maintaining its connection to Link 1 with (EHT)AP MLD 1. After the handover is complete, non-AP MLD 1 disconnects Link 1 with (EHT)AP MLD 1. Therefore, for non-AP MLD 1, there is no interruption during the entire handover process. This is the seamless roaming mechanism designed in detail in the embodiments of this application.

The embodiments of the present application propose the complete process of non-AP MLD performing hitless switching between AP MLDs, as well as the signaling interaction and frame structure design required to support hitless switching.

As shown in Figure 1C, before non-AP MLD 1 moves, it establishes Link 1, Link 2, and Link 3 with (EHT) AP MLD 1 for communication. After non-AP MLD 1 moves (or the communication environment changes), non-AP MLD 1 needs to switch to the nearby (EHT) AP MLD 2. During this process, non-AP MLD 1, (EHT) AP MLD 1, or the target (EHT) AP MLD 2 may initiate roaming. When roaming is initiated, (EHT) AP MLD 1 and the target (EHT) AP MLD 2 may need to perform context migration and information conversion. When roaming, non-AP MLD 1 can establish new links (Link 2 and Link 3) with the target (EHT) AP MLD 2) while maintaining its link with (EHT) AP MLD 1 (Link 1 in the figure). After roaming is complete, non-AP MLD 1 or (EHT)AP MLD 2 can declare the roaming complete. Non-AP MLD 1 and/or (EHT)AP MLD 2 then perform subsequent operations. If a failure occurs during the preceding process, recovery is required.

As shown in Figure 1C, non-AP MLD 1 roams or switches to AP MLD 1 because it moves away from (current) AP MLD 1, causing the link quality between it and AP MLD 1 to degrade (for example, the link quality RSSI, signal-to-noise ratio (SNR), or signal-to-interference-plus-noise ratio (SINR) falls below a certain threshold). Meanwhile, it moves closer to (target) AP MLD 2, making the link quality between it and AP MLD 2 sufficient to support normal communication (for example, the link quality RSSI, signal-to-noise ratio (SNR), or signal-to-interference-plus-noise ratio (SINR) exceeds a certain threshold). Alternatively, changes in the channel state or communication environment may cause the link quality between non-AP MLD 1 and AP MLD 1 to degrade (for example, the link quality RSSI, signal-to-noise ratio (SNR), or signal-to-interference-plus-noise ratio (SINR) falls below a certain threshold or is interrupted). Meanwhile, the link quality between non-AP MLD 1 and AP MLD 2 improves to support normal communication (for example, the link quality RSSI, signal-to-noise ratio (SNR), or signal-to-interference-plus-noise ratio (SINR) exceeds a certain threshold).

The embodiments of this application propose the following technical solutions:

1) Design of the method to initiate roaming.

a) Non-AP MLD initiates roaming.

b) The method used by the current AP MLD to initiate roaming.

c) Method for target AP MLD to initiate roaming.

d) Design of signaling and frame format for initiating roaming.

2) Design of context migration between current AP MLD and target AP MLD.

a) Signaling and frame format design for context migration.

b) A method for converting the information indicated by context migration between the current AP MLD and the target AP MLD.

3) Roaming completion determination method and subsequent operation design.

a) Confirmation method for Non-AP MLD roaming completion.

b) Confirmation method for target AP MLD roaming completion.

c) The signaling and frame structure design used when roaming is completed.

d) Design subsequent behaviors after roaming is completed.

To facilitate understanding of the technical solutions of the embodiments of the present application, the technical solutions related to the embodiments of the present application are described below.

Method design for initiating roaming:

Non-AP MLD roaming method:

Figure 2A is a flow chart of a communication method based on multi-link device roaming provided in an embodiment of the present application. As shown in Figure 2A, the communication method based on multi-link device roaming is executed on a non-access point multi-link device non-AP MLD, wherein the communication method includes at least one of the following operations: operation 201A: the non-AP MLD establishes a multi-link connection with the first access point multi-link device AP MLD 1; operation 202A: the non-AP MLD requests roaming from the AP MLD 1 or the second access point multi-link device AP MLD 2; and operation 203A: after roaming is completed, the non-AP MLD establishes a multi-link connection with the AP MLD 2.

Through the above technical solution, the non-AP MLD requests roaming from the AP MLD 1 or AP MLD 2, and after roaming is completed, the non-AP MLD establishes a multi-link connection with the AP MLD 2, thereby improving the experience of the non-AP MLD when roaming on the AP MLD 2 and achieving basically uninterrupted roaming.

As previously described, AP MLD1 is the multi-link device currently connected to the non-AP MLD, and AP MLD2 is the multi-link device to which the non-AP MLD wishes to roam. This embodiment of the application includes two scenarios: the non-AP MLD requests roaming from AP MLD1 and the non-AP MLD requests roaming from AP MLD2.

In some embodiments of the present application, after the non-AP MLD establishes a multi-link connection with AP MLD 2, the non-AP MLD disconnects the multi-link connection established with AP MLD 1. In some embodiments of the present application, after the non-AP MLD establishes a multi-link connection with AP MLD 2, the non-AP MLD still maintains the multi-link connection with AP MLD 1. In some embodiments of the present application, before the non-AP MLD requests roaming from AP MLD 1, the non-AP MLD sends a first frame to AP MLD 2 and receives a second frame sent by AP MLD 2. The non-AP MLD determines whether to request roaming from AP MLD 1 based on the second frame. In some embodiments of the present application, the first frame and the second frame include one of the following combinations: a request to send RTS frame and a clear to send CTS frame, a probe request frame and a probe response frame, a multilink probe request frame and a multilink probe response frame, or a fast basic service set handover FT request frame and a FT response frame.

In some embodiments of the present application, before the non-AP MLD requests roaming from AP MLD 1, the non-AP MLD receives a second frame sent by AP MLD 2, and the non-AP MLD determines whether to request roaming from AP MLD 1 based on the second frame. In some embodiments of the present application, the second frame comprises a beacon frame. In some embodiments of the present application, the non-AP MLD determining whether to request roaming from AP MLD 1 based on the second frame includes: the non-AP MLD confirming link status information between the non-AP MLD and AP MLD 2 using the second frame; and/or the non-AP MLD confirming status information of AP MLD 2 using the second frame.

In some embodiments of the present application, the link status information between the non-AP MLD and the AP MLD 2 includes received signal strength indication RSSI, channel state information CSI, signal-to-interference-plus-noise ratio SINR, signal-to-noise ratio SNR, reference signal received power RSRP, and/or reference signal received quality RSRQ. Through this information, the Non-AP MLD can determine whether the link status between itself and AP MLD 2 meets the requirements for establishing a connection. For example, for each of the above indications/information, a reference threshold can be set separately in the Non-AP MLD, or a weighted calculation threshold associated with the above information can be set. When the value of the received indication/information reaches a preset threshold, it is considered that the link status meets the requirements for establishing a connection.

In some embodiments of the present application, the status information of the AP MLD 2 includes a power status indication, a roaming available window, a roaming unavailable window, a basic service set BSS load, a channel load, a maximum number of supported sites STA/non-AP MLD, and/or mobile AP MLD information. Through this information, the Non-AP MLD can know whether the current status of the AP MLD2 meets the requirements for establishing a connection. For example, similarly, for each of the above indications/information, a reference threshold can be set separately in the Non-AP MLD, or a weighted calculation threshold associated with the above information can be set. When the value of the received indication/information reaches a preset threshold, it is considered that The AP MLD state 2 meets the requirements for establishing a connection.

In some embodiments of the present application, the non-AP MLD requesting roaming from the AP MLD 1 includes: the non-AP MLD sending a first link reconfiguration frame to the AP MLD 1, and receiving a second link reconfiguration frame sent by the AP MLD 1. In some embodiments of the present application, the non-AP MLD requesting roaming from the AP MLD 2 includes: the non-AP MLD sending a first link reconfiguration frame to the AP MLD 2, and receiving a second link reconfiguration frame sent by the AP MLD 2. In some embodiments of the present application, the first link reconfiguration frame includes a reconfiguration multilink element. It should be understood that the specific implementation of the first link reconfiguration frame is not limited thereto and can be adjusted according to actual needs.

In some embodiments of the present application, the existence bit map subfield of the reconfigured multi-link element includes a multi-link device MLD media access control MAC address existence field, an enhanced multi-link EML capability existence field, an MLD capability and operation existence field, and/or a roaming information existence field, wherein: the MLD MAC address existence field is used to indicate whether the general information field of the reconfigured multi-link element has an MLD MAC address field; the EML capability existence field is used to indicate whether the general information field of the reconfigured multi-link element has an EML capability field; the MLD capability and operation existence field is used to indicate whether the general information field of the reconfigured multi-link element has an MLD capability and operation field; the roaming information existence field is used to indicate whether the general information field or link information field of the reconfigured multi-link element has a roaming information field.

In some embodiments of the present application, the general information field of the reconfigured multi-link element includes an MLD MAC address field, an EML capability field, an MLD capability and operation field, and a roaming information field, wherein: the MLD MAC address field is used to indicate the MLD MAC address of the AP MLD 2; the EML capability field is used to indicate the enhanced multi-link information of the non-AP MLD; the MLD capability and operation field is used to indicate the multi-link capability information and operation parameters of the non-AP MLD; the roaming information field is used to indicate one or more of the following information: channel information, resource scheduling information, power information, maximum number of transmit/receive spatial streams, enhanced distributed channel access EDCA parameter set, emergency preparedness communication service EPCS information, buffer status report BSR information, sequence number SN, data packet number PN, block acknowledgment BA session information, multi-access point AP mode, power information, target wake-up time TWT information, target wake-up time service phase R-TWT SP information, service identifier to link TID-to-Link mapping, extended capability information, and extremely high throughput EHT capability information.

In some embodiments of the present application, the channel information is used to indicate the channel information supported by the non-AP MLD and/or the channel information corresponding to the link established by the non-AP MLD; the resource scheduling information is used to indicate the resource unit RU information used by the non-AP MLD to communicate with the AP MLD 1; the power information is used to indicate the transmission power information used by the non-AP MLD to communicate with the AP MLD 1; the maximum number of transmit/receive spatial streams is used to indicate the maximum number of transmit/receive spatial streams supported by the non-AP MLD; the enhanced distributed channel access EDCA parameter set is used to indicate the number of transmit/receive spatial streams supported by the non-AP MLD. The EDCA parameter set may be used to indicate the EDCA parameter set established between the non-AP MLD and the AP MLD 1; the emergency preparedness communication service EPCS information may be used to indicate the EPCS capability information, EPCS subscription information and EPCS activation status information supported by the non-AP MLD, and/or may be used to indicate the EDCA parameter set that the non-AP MLD requests to establish an EPCS priority access permission and EPCS priority access with the AP MLD 2; the buffer status report BSR information may be used to indicate the buffer status information of the non-AP MLD; the sequence number SN may be used to indicate the SN of the frame between the non-AP MLD and the AP MLD 1; The data packet number PN is used to indicate the PN that has been sent between the non-AP MLD and the AP MLD 1, or the PN that is about to be sent, or the PN that has not been sent; the block acknowledgment BA session information is used to indicate the block acknowledgment session information established between the non-AP MLD and the AP MLD 1; the multi-access point AP mode is used to indicate the multi-AP collaboration mode supported by the non-AP MLD; the power information is used to indicate the sleep policy information and/or the supported sleep mechanism of the non-AP MLD; the target wake-up time TWT information is used to indicate the TWT information established between the non-AP MLD and the AP MLD 1; the limited target wake-up time The service phase R-TWT SP information is used to indicate the R-TWT SP information established between the non-AP MLD and the AP MLD 1; the service identifier to link TID-to-Link mapping is used to indicate the TID-to-Link mapping scheme established between the non-AP MLD and the AP MLD 1, or used to indicate the TID-to-Link mapping scheme of the link established between the non-AP MLD request and the AP MLD 2; the extended capability information is used to indicate the extended capability information of the non-AP MLD; the extremely high throughput EHT capability information is used to indicate the EHT capability information of the non-AP MLD.

In some embodiments of the present application, the reconfiguration multi-link element includes a per-site summary sub-element for carrying summary information of the non-AP MLD that initiated roaming. In some embodiments of the present application, the per-site summary sub-element includes a STA control field, and the STA control field includes a link identifier ID field, a reconfiguration operation type field, a new link ID exists field, and/or a roaming information exists field, wherein: the link ID field is used to indicate the link ID; the new link ID exists field is used to indicate whether a new link ID information field exists in the STA information field of the reconfiguration multi-link element; and the roaming information exists field is used to indicate whether a roaming information field exists in the link information field of the reconfiguration multi-link element.

In some embodiments of the present application, when the value indicated by the reconfiguration operation type field is 5, the reconfiguration operation type field is set to the meaning/operation of switching the link. In some embodiments of the present application, when the reconfiguration operation type field indicates switching When the Link field and/or the New Link ID Present field of the STA Control field indicates "Present", the Link ID field in the STA Control field indicates the ID of the link between the non-AP MLD and AP MLD 1 being disconnected, and the New Link ID Information field indicates the ID of the link for establishing a connection between the non-AP MLD and AP MLD 2. In some embodiments of the present application, when the Reconfiguration Operation Type field indicates "Switch Link" and/or the New Link ID Present field of the STA Control field indicates "Present", the Link ID field in the STA Control field indicates the ID of the link for establishing a connection between the non-AP MLD and AP MLD 2, and the New Link ID Information field indicates the ID of the link between the non-AP MLD and AP MLD 1 being disconnected.

In some embodiments of the present application, the new link ID information field includes a link ID field, which is used to indicate an identifier of a link, wherein the new link ID information field also includes a link ID extension field, and the link ID field and the link ID extension field jointly indicate the new link ID established between the non-AP MLD and the AP MLD 2. In some embodiments of the present application, the second link reconfiguration frame includes a reconfiguration status list field. In some embodiments of the present application, the reconfiguration status list field includes one or more reconfiguration status dual subfields, and the reconfiguration status dual subfield includes a link ID information field and a status field. In some embodiments of the present application, the link ID information field includes a link ID subfield, and the link ID subfield indicates the link ID of the AP, indicating the addition or deletion of the link ID of the AP in the first link reconfiguration frame.

In some embodiments of the present application, the status field includes a first status code, a second status code, a third status code, a fourth status code, and/or a fifth status code, wherein the first status code indicates that the roaming request is rejected because the BSS load of the AP MLD 2 is greater than a first set value, the second status code indicates that the roaming request is rejected because the channel load for establishing a link is greater than a second set value, the third status code indicates that the roaming request is rejected because the time for requesting link establishment does not match the window allowed for link establishment by the AP MLD 2, the fourth status code indicates that the AP will enter a dormant state and temporarily not accept roaming requests, and the fifth status code indicates that the roaming request is rejected because the AP MLD 2 has reached the maximum number of supported STAs/non-AP MLDs. In some embodiments of the present application, the second link reconfiguration frame also includes a basic multilink element, the presence bitmap field of the basic multilink element includes a roaming information presence field, wherein the roaming information presence field indicates whether a roaming information field exists in the general information field or the link information field of the basic multilink element.

In some embodiments of the present application, the general information field of the basic multi-link element includes an MLD MAC address field, which is used to indicate the MLD MAC address of the AP MLD 2. In some embodiments of the present application, the general information field of the basic multi-link element also includes a link ID information field, a BSS parameter change count field, a media synchronization delay information field, an EML capability field, an MLD capability and operation field, an AP MLD ID field, and/or an extended MLD capability and operation field, and the contents indicated by the link ID information field, the BSS parameter change count field, the media synchronization delay information field, the EML capability field, the MLD capability and operation field, the AP MLD ID field, and/or the extended MLD capability and operation field refer to related information between the non-AP MLD and the AP MLD 2.

In some embodiments of the present application, the roaming information field is used to indicate one or more of the following information: channel information, resource scheduling information, power information, a maximum number of transmit/receive spatial streams, an EDCA parameter set, EPCS information, BSR information, SN, PN, BA session information, multi-AP mode, power information, TWT information, R-TWT SP information, TID-to-Link mapping, extended capability information, and EHT capability information, wherein: the channel information is used to indicate channel information supported by the non-AP MLD and/or channel information corresponding to the link established by the non-AP MLD; the resource scheduling information is used to indicate RU information used by the non-AP MLD to communicate with the AP MLD 1; the power information is used to indicate transmit power information used by the non-AP MLD to communicate with the AP MLD 1; the maximum number of transmit/receive spatial streams is used to indicate the maximum number of transmit/receive spatial streams supported by the non-AP MLD; the EDCA parameter set is used to indicate an EDCA parameter set supported by the non-AP MLD or to indicate the EDCA parameter set supported by the non-AP MLD or the EDCA parameter set established by the non-AP MLD. 1; the EPCS information is used to indicate the EPCS capability information, EPCS subscription information and EPCS activation status information supported by the non-AP MLD, and/or the EDCA parameter set for indicating that the non-AP MLD requests to establish an EPCS priority access permission and EPCS priority access with the AP MLD 2; the BSR information is used to indicate the cache status information of the non-AP MLD; the SN is used to indicate the SN of the frame between the non-AP MLD and the AP MLD 1; the PN is used to indicate the PN that has been sent, the PN to be sent, or the PN not sent between the non-AP MLD and the AP MLD 1; the BA session information is used to indicate the block confirmation session information established between the non-AP MLD and the AP MLD 1; the multi-AP mode is used to indicate the multi-AP cooperation mode supported by the non-AP MLD; the power information is used to indicate the sleep policy information and/or the supported sleep mechanism of the non-AP MLD; the TWT information is used to indicate the sleep policy information and/or the supported sleep mechanism of the non-AP MLD 1; the R-TWT SP information is used to indicate the R-TWT SP information established between the non-AP MLD and the AP MLD 1; the TID-to-Link mapping is used to indicate the TID-to-Link mapping scheme established between the non-AP MLD and the AP MLD 1, or is used to indicate the TID-to-Link mapping scheme of the link established between the non-AP MLD request and the AP MLD 2; the extended capability information is used to indicate the extended capability information of the non-AP MLD; the EHT capability information is used to indicate the Describes the EHT capability information of non-AP MLD.

In some embodiments of the present application, the link information field of the basic multi-link element includes a per-site summary sub-element, the per-site summary sub-element includes a STA control field, and the STA control field includes a roaming information presence field. In some embodiments of the present application, the roaming information presence field is used to indicate whether a roaming information field exists in the link information field of the basic multi-link element. In some embodiments of the present application, the communication method further includes the non-AP MLD starting a timer to determine the time interval between the non-AP MLD sending the first link reconfiguration frame and the non-AP MLD receiving the second link reconfiguration frame. In some embodiments of the present application, after the non-AP MLD sends the first link reconfiguration frame, it starts the timer. If the non-AP MLD receives the second link reconfiguration frame within the time specified by the timer, the non-AP MLD determines whether to roam based on the second link reconfiguration frame.

In some embodiments of the present application, after the non-AP MLD sends the first link reconfiguration frame, the timer is started. If the non-AP MLD does not receive the second link reconfiguration frame within the time corresponding to the timer, the non-AP MLD determines that the roaming has failed.

Specifically, in some embodiments of the present application, FIG2B illustrates several methods for a non-AP MLD to initiate roaming. As shown in FIG2B , in the initial state, the non-AP MLD establishes multiple links with AP MLD 1 (also referred to as the current AP MLD). For example, Link 1 is established between non-AP STA 1, which is affiliated with non-AP MLD 1, and AP 1, which is affiliated with AP MLD 1. Link 2 is established between non-AP STA 2, which is affiliated with non-AP MLD 1, and AP 2, which is affiliated with AP MLD 1. Link 3 is established between non-AP STA 3, which is affiliated with non-AP MLD 1, and AP 3, which is affiliated with AP MLD 1. After roaming is completed, the non-AP MLD establishes multiple links with AP MLD 2 (also called the target AP MLD). For example, link 2' is established between non-AP STA 2, which is subordinate to non-AP MLD 1, and AP 2, which is subordinate to AP MLD 1. Link 3' is established between non-AP STA 3, which is subordinate to non-AP MLD 1, and AP 3, which is subordinate to AP MLD 1. In addition, the non-AP MLD disconnects the multiple links (i.e., link 1, link 2, and link 3) established with AP MLD 1.

Example 1: (Method 1) The non-AP MLD requests roaming from the (current) AP MLD 1:

Because the non-AP MLD may not be aware of whether the target AP MLD 2 in its vicinity is suitable as a roaming target, the non-AP MLD may need to send a request frame to the target AP MLD 2 before requesting roaming from the (current) AP MLD 1 (optional, as shown by the dotted line "Request Frame 1" in Figure 2B). The non-AP MLD then uses the response frame (as shown by the dotted line "Response Frame 1" in Figure 2B) sent by the target AP MLD 2 to determine whether a roaming request can be initiated to the (current) AP MLD 1. The non-AP MLD's operation of sending a request frame to the target AP MLD 2 and receiving a response frame has one or more of the following effects:

Function 1: Confirm whether the link quality between the non-AP MLD and the target AP MLD 2 is sufficient for communication.

After the non-AP MLD sends a request frame 1 to the target AP MLD 2, the target AP MLD 2 replies with a response frame 1. The non-AP MLD determines whether to roam to the target AP MLD 2 based on the quality of the received response frame 1, such as the received signal strength indicator RSSI, channel state information CSI, signal-to-interference-plus-noise ratio SINR, signal-to-noise ratio SNR, and other indicators. The request frame 1 and response frame 1 can be one of the following combinations:

The request frame 1 is an RTS frame, and the response frame 1 is a CTS frame.

The request frame 1 is a probe request frame, and the response frame 1 is a probe response frame.

The request frame 1 is a multi-link detection request frame, and the response frame 1 is a multi-link detection response frame.

The request frame 1 is an FT request frame, and the response frame 1 is an FT response frame.

The quality of the received response frame 1, for example, RSSI is greater than or equal to the first threshold (dBm). The first threshold may be a predefined threshold. The quality of the received response frame 1, for example, the relevant index of CSI is greater than or equal to the second threshold. The second threshold may be a predefined threshold. The quality of the received response frame 1, for example, SINR is greater than or equal to the third threshold (dB). The third threshold may be a predefined threshold. The quality of the received response frame 1, for example, SNR is greater than or equal to the fourth threshold (dB). The fourth threshold may be a predefined threshold. In some embodiments, the judgment threshold may also correspond to the result of the weighted summation of some or all of the above parameters, that is, the influence weights are preconfigured for the relevant parameters, and the weighted sum is compared with the preset threshold.

In addition, if the non-AP MLD does not send a request frame 1 to the target AP MLD 2, the target AP MLD 2 can proactively send a response frame 1 to the non-AP MLD. The non-AP MLD determines whether to roam to the target AP MLD 2 based on the quality of the received response frame 1 (such as RSSI, CSI, SINR, SNR, etc.). In this case, the response frame 1 can be a beacon frame.

The quality of the received response frame 1, for example, RSSI is greater than or equal to the first threshold (dBm). The first threshold may be a predefined threshold. The quality of the received response frame 1, for example, CSI related indicators are greater than or equal to the second threshold. The second threshold may be a predefined threshold. The quality of the received response frame 1, for example, SINR is greater than or equal to the third threshold (dB). The third threshold may be a predefined threshold. The quality of the received response frame 1, for example, SNR is greater than or equal to the fourth threshold (dB). The fourth threshold may be a predefined Threshold. In some embodiments, the judgment threshold may also correspond to the result of a weighted sum of some or all of the above parameters, that is, pre-configured influence weights are applied to the relevant parameters, and the weighted sum is compared with the preset threshold.

Function 2: Confirm whether the current status of target AP MLD 2 accepts roaming from non-AP MLD.

After the non-AP MLD sends a request frame 1 to the target AP MLD 2, the target AP MLD 2 replies with a response frame 1. The non-AP MLD determines whether to roam to the target AP MLD 2 based on the indication in the received response frame 1. The specific indication is one or more of the following fields/information in the target AP MLD 2:

Battery status indication: used to indicate whether the current battery status can still accept new non-AP MLD for roaming. For example, if the battery status indication (or power management indication) is equal to 1, it means that the device has not entered the sleep state and can accept roaming requests; if the battery status indication (or power management indication) is equal to 0, it means that the device will enter the sleep state and will not accept roaming requests for the time being; and vice versa.

Availability Window: This indicates the window in which the current device will accept new non-AP MLDs for roaming. This window includes the start time, duration, and period/interval of the window. The non-AP MLD uses this information to determine when to initiate a roaming request.

Roaming Unavailable Window: This window indicates that the current device will not accept new non-AP MLDs for roaming. This window includes the start time, duration, and period/interval of the window. Non-AP MLDs use this information to determine when to initiate roaming requests, avoiding the time indicated by the roaming unavailable window and requesting roaming outside of the window.

BSS load: Used to indicate the load of the BSS where the current device is located. If the BSS load indicates that the load is too high, the non-AP MLD can not request roaming to the target AP MLD 2 based on this information; if the BSS load indicates that the load is low, the non-AP MLD can request roaming to the target AP MLD 2 based on this information.

Channel load: Used to indicate the load status of each channel currently supported by the device. If the channel load indicates that the load of a certain channel is too high, the non-AP MLD can not request to roam to the target AP MLD 2 based on this information, or can request to establish a new link through a channel with less load based on this information.

Maximum total number of STAs supported: used to indicate the total number of STAs/non-AP MLDs supported (or capable of being served) by the current device. If the number of STAs/non-AP MLDs being served by the current device is equal to the number indicated by the maximum total number of STAs supported, then the non-AP MLD will not roam towards the target AP MLD 2 based on this information.

Mobility AP MLD information: Indicates whether the current device is a mobility AP MLD (and the capabilities and parameters supported by it as a mobility AP MLD). If it is a mobility AP MLD, due to its limited capabilities, the non-AP MLD may not initiate a roaming request to the device in order to find a target AP MLD with more reliable communication. If it is not a mobility AP MLD, the non-AP MLD may initiate a roaming request to the device.

Through the above signaling exchanges, the non-AP MLD obtains the status information of the target AP MLD 2 and the link status information between them. Based on this information, the non-AP MLD decides whether to request (current) AP MLD 1 to roam to the target AP MLD 2. If the non-AP MLD decides to roam to the target AP MLD 2, it sends a Link Reconfiguration Request frame (on Link 1) to (current) AP MLD 1 to initiate roaming. Then, (current) AP MLD 1 responds with a Link Reconfiguration Response frame (on Link 1) to notify the roaming result. During this process, context migration is also performed between (current) AP MLD 1 and (target) AP MLD 2. For details, see the designs of some embodiments of this application below.

Link reconfiguration request frame format design:

The action field format of the link reconfiguration request frame is shown in Table 2 below:

Table 2: Link Reconfiguration Request Frame Operation Field Format

Dialog Token: The Dialog Token field is set to a non-zero value by the non-access point multilink device that sends the Link Reconfiguration Request frame.

The Reconfiguration Multi-Link element includes the Presence Bitmap subfield, the Common Info field, and the Per-STA Profile subelement, as follows:

FIG2C is a schematic diagram of the format of the presence bitmap subfield of the reconfiguration multi-link element provided in an embodiment of the present application, and FIG2D is a schematic diagram of the format of the common information field of the reconfiguration multi-link element provided in an embodiment of the present application. As shown in FIG2C , MLD MAC Address Present is equal to 1 and is used to indicate that the common information field of the reconfiguration multi-link element shown in FIG2D contains the MLD MAC Address field, and MLD MAC Address Present is equal to 0 and is used to indicate that the common information field of the reconfiguration multi-link element shown in FIG2D does not contain the MLD MAC Address field.

The EML capability exists equal to 1, which is used to indicate that the common information field (Common Info field) of the reconfiguration multi-link element (Reconfiguration Multi-Link element) shown in Figure 2D has EML capability. The EML capability exists equal to 0, which is used to indicate that the common information field (Common Info field) of the reconfiguration multi-link element (Reconfiguration Multi-Link element) shown in Figure 2D does not have EML capability.

The MLD capability and operation exists equal to 1, which is used to indicate that the MLD capability and operation field exists in the common information field (Common Info field) of the reconfiguration multi-link element (Reconfiguration Multi-Link element) shown in Figure 2D. The MLD capability and operation exists equal to 0, which is used to indicate that the MLD capability and operation field does not exist in the common information field (Common Info field) of the reconfiguration multi-link element (Reconfiguration Multi-Link element) shown in Figure 2D.

In addition, an embodiment of the present application proposes to define any bit (for example, bit 3) in B3 to B11 of the presence bitmap subfield of the reconfiguration multi-link element (Reconfiguration Multi-Link element) as a roaming information presence field.

The roaming information exists is used to indicate whether there is a roaming information field in the common information field (Common Info field) of the reconfiguration multi-link element (Reconfiguration Multi-Link element) shown in FIG2D . For example, if the roaming information exists is equal to 0, it means that there is no roaming information field in the common information field (Common Info field) of the reconfiguration multi-link element (Reconfiguration Multi-Link element) shown in FIG2D ; if the roaming information exists is equal to 1, it means that there is a roaming information field in the common information field (Common Info field) of the reconfiguration multi-link element (Reconfiguration Multi-Link element) shown in FIG2D .

The format of the Common Info field of the Reconfiguration Multi-Link element has been modified:

It is worth noting that in order to enable the non-AP MLD to request the (current) AP MLD 1 to roam to the (target) AP MLD 2, the embodiment of the present application proposes that when there is a roaming information field in the Common Info field of the Reconfiguration Multi-Link element in Figure 2D (that is, the roaming information presence in the Presence Bitmap subfield of the Reconfiguration Multi-Link element in Figure 2C is equal to 1), the MLD MAC address in the Common Info field of the Reconfiguration Multi-Link element should indicate the MLD MAC address of the (target) AP MLD 2. The content indicated by the EML capability field in the Common Info field of the Reconfiguration Multi-Link element refers to the enhanced multi-link information of non-AP MLD (the specific content is consistent with the IEEE 802.11be standard), and the content indicated by the MLD capability and operation fields in the Common Info field of the Reconfiguration Multi-Link element refers to the multi-link capability information and operation parameters of non-AP MLD (the specific content is consistent with the IEEE 802.11be standard).

The roaming information field in the Common Info field of the Reconfiguration Multi-Link element is a new field added in the embodiment of the present application and is used to indicate one or more of the following information:

Channel and bandwidth: Used to indicate the channel information (including channel bandwidth, channel number, etc.) supported by the non-AP MLD initiating roaming and/or the channel information (including channel bandwidth, channel number, etc.) corresponding to the new link that the non-AP MLD initiating roaming wants to establish.

RU allocation: Used to indicate the RU (index) information used by the non-AP MLD initiating roaming to communicate with the (current) AP MLD 1.

Power Limit: Used to indicate the transmit power information (such as maximum transmit power, minimum transmit power, etc.) used by the non-AP MLD initiating roaming to communicate with the (current) AP MLD 1.

Max TX/RX Nss: Used to indicate the maximum number of transmit/receive spatial streams (Spatial Stream) supported by the non-AP MLD initiating roaming.

EDCA parameter set: used to indicate the EDCA parameter set supported by the non-AP MLD initiating roaming, or used to indicate the EDCA parameter set established between the non-AP MLD initiating roaming and (current) AP MLD 1 (the purpose of the non-AP MLD carrying the EDCA parameter set in the link reconfiguration request frame is to allow the non-AP MLD and (target) AP MLD 2 to establish a similar/new EDCA parameter set based on the EDCA parameter set).

EPCS information: used to indicate the EPCS capability information, EPCS subscription information and EPCS activation status information supported by the non-AP MLD initiating roaming. It can also be used by the non-AP MLD to request to establish EPCS priority access permission and EDCA parameter set for EPCS priority access with (target) AP MLD 2.

BSR related information: used to indicate the cache status information of the non-AP MLD that initiated roaming (for specific details and content, see the BSR control subdomain and/or QoS control field in the IEEE 802.11 standard, including cache size, cache service type and other information).

SN: Used to indicate the sequence number of the frame between the non-AP MLD initiating roaming and the (current) AP MLD 1.

PN: PN is used to number the MPDUs in the Media Access Control (MAC) layer Service Data Units (MSDUs), A-MSDUs, and MMPDUs. It indicates the number of packets that have been sent, the number of packets that are about to be sent, or the number of remaining packets that have not been sent between the non-AP MLD initiating roaming and the (current) AP MLD 1.

BA-related information: used to indicate the BlockAck session information established between the non-AP MLD initiating roaming and the (current) AP MLD 1, such as the BA protocol, BA scoreboard, etc. For details, see the IEEE 802.11 standard.

Multi-AP mode: used to indicate the multi-AP collaboration mode supported by the non-AP MLD that initiates roaming, such as C-TDMA, C-OFDMA, C-SR, C-BF, J-TX, etc.

Power-related information: used to indicate the sleep policy information of the non-AP MLD that initiates roaming, such as the sleep window information (sleep start time, sleep duration, sleep window interval, etc.) and/or the supported sleep mechanisms.

TWT element: Used to indicate the TWT information established between the non-AP MLD initiating roaming and the (current) AP MLD 1.

R-TWT SP: used to indicate the R-TWT SP information established between the non-AP MLD initiating roaming and the (current) AP MLD 1.

TID-to-Link mapping: used to indicate the establishment of a TID-to-Link mapping scheme between the non-AP MLD initiating roaming and the (current) AP MLD 1, serving as a reference for TID-to-Link mapping when assisting the non-AP MLD in establishing a new link with the (target) AP MLD 2; or used to indicate the TID-to-Link mapping scheme for establishing a new link between the non-AP MLD requesting the roaming initiation and the (target) AP MLD 2.

Extended capability element: used to indicate the extended capability information of the non-AP MLD initiating roaming. For details, see the IEEE 802.11 baseline standard specification.

EHT capability element: used to indicate the extremely high throughput capability information of the non-AP MLD initiating roaming. For details, see the IEEE 802.11be standard specification.

The format of the Per-STA Profile subelement of the Reconfiguration Multi-Link element has been modified:

FIG2E is a schematic diagram illustrating the format of a per-STA profile subelement of a reconfiguration multi-link element according to an embodiment of the present application. FIG2E illustrates the format of a per-STA profile subelement of a reconfiguration multi-link element. The per-STA profile subelement carries a per-STA profile of a non-AP MLD that initiates roaming.

Figure 2F is a schematic diagram of the STA Control field format of the Reconfiguration Multilink Element provided in an embodiment of the present application. As shown in Figure 2F, this embodiment of the present application proposes adding a new reconfiguration operation type to the reconfiguration operation types, as shown in Table 3. A reconfiguration operation type order of 5 is defined as a link switching method.

Table 3: Reconfiguration Operation Type Subfield Coding

In addition, Figure 2G is a schematic diagram of the STA control field format of the reconfiguration multi-link element provided in an embodiment of the present application. The embodiment of the present application proposes to define any one bit (for example, Bit 14) of Bit 14 and Bit 15 of the STA control field as a new link ID existence field. When the new link ID existence is equal to 1, it represents that the new link ID information field exists in the STA information field of the reconfiguration multi-link element (Reconfiguration Multi-Link element) (see Figure 2G); when the new link ID existence is equal to 0, it represents that the new link ID information field does not exist in the STA information field of the reconfiguration multi-link element (Reconfiguration Multi-Link element). The embodiment of the present application proposes to define any one bit (for example, Bit 15) of Bit 14 and Bit 15 (Bit 15) of the STA control field as a roaming information existence field. When the roaming information existence is equal to 1, it represents the reconfiguration multi-link element (Reconfiguration Multi-Link element) There is a roaming information field in the STA information field of the reconfiguration multi-link element (see Figure 2G); when the roaming information field is equal to 0, it means that there is no roaming information field in the STA information field of the reconfiguration multi-link element (Reconfiguration Multi-Link element).

When the Reconfiguration Operation Type in the STA Control field of the Reconfiguration Multi-Link element is set to (order) 5 (i.e., the link switching method defined in the embodiment of the present application), the New Link ID in the STA Control field needs to be set to 1, which means that the New Link ID information (specific format is shown in Figure 2H) is present in the STA Information field (see Figure 2G) of the Reconfiguration Multi-Link element. At this time, the Link ID field in the STA Control field of the Reconfiguration Multi-Link element indicates the link ID that needs to be disconnected from the (current) AP MLD 1, and the New Link ID information field (specific format is shown in Figure 2H) in the STA Information field of the Reconfiguration Multi-Link element indicates the link ID that needs to be established with the (target) AP MLD 2. The new link (corresponding to the link ID in the new link ID information field of the STA information field) is established first, and then the old link (corresponding to the link ID field of the STA control field) is disconnected.

Figure 2H is a schematic diagram of the new link ID information field in the STA information field format provided in an embodiment of the present application. The specific format of the new link ID information field is shown in Figure 2H, which includes a 4-bit link ID field and a 4-bit link ID extension field, wherein the link ID field can be used to indicate the identifier of a conventional link (that is, the link ID is equal to 0 to 14). When the identifier of the conventional link is not sufficient, the link ID field and the link ID extension field jointly indicate the link ID of the new link to be established between the non-AP MLD and the (target) AP MLD 2.

It is worth noting that the roaming information field in the previous example is carried by the Common Info field of the Reconfiguration Multi-Link element. In addition, the roaming information field can also be carried by the STA information field of the Reconfiguration Multi-Link element. The content of the roaming information field is consistent with the roaming information field in the Common Info field above and will not be repeated here.

Link reconfiguration response frame format design:

The format of the action field of the link reconfiguration response frame is shown in Table 4 below:

Table 4: Link Reconfiguration Response Frame Operation Field Format

The Dialog Token field is set to the value of the Dialog Token field in the corresponding Repository Reconfiguration Request frame. The Count subfield is set to the number of Reconfiguration Status binaries in the Reconfiguration Status List subfield. The Reconfiguration Status List subfield contains one or more Reconfiguration Status binaries. The format of the Reconfiguration Status binary subfield is shown in Figure 2I.

The format of the Link ID Info subfield includes a 4-bit Link ID subfield and a 4-bit reserved field. The Link ID subfield in the Link ID Info subfield indicates the link identifier of the AP being added or deleted in the corresponding warehouse reconfiguration request frame. The Status subfield indicates the status of the link reconfiguration operation for the link corresponding to the Link ID subfield, as shown in Table 5 (Status Code). The five status codes listed in Table 5 below are newly added in the embodiments of this application. For their specific functions, see the meaning description.

Table 5: Status Codes

Figure 2J is a schematic diagram of the format of the presence bitmap subfield provided in an embodiment of the present application, and Figure 2K is a schematic diagram of the format of the common information field of the basic multilink element provided in an embodiment of the present application. If the AP MLD accepts at least one link addition, a basic multilink element is included to provide per-site overview information for one or more APs corresponding to the link settings successfully added to the non-AP MLD. Otherwise, the basic multilink element is not included. The basic multilink element includes fields such as the multilink control field, the common information field (Common Info field), and the link information field, as follows: The format of the presence bitmap subfield (Presence Bitmap subfield) of the multilink control field in the basic multilink element is defined in Figure 2J. The embodiment of the present application proposes to define any bit (for example, bit 7) from B7 to B11 of the presence bitmap subfield (Presence Bitmap subfield) of the basic multilink element as the roaming information presence field.

The roaming information exists is used to indicate whether there is a roaming information field in the common information field (Common Info field) of the basic multi-link element shown in Figure 2K. For example, if the roaming information exists is equal to 0, it means that there is no roaming information field in the common information field (Common Info field) of the basic multi-link element shown in Figure 2K; if the roaming information exists is equal to 1, it means that there is a roaming information field in the common information field (Common Info field) of the basic multi-link element shown in Figure 2K.

Modification of the format of the Common Info field of the basic multi-link element: It is worth noting that in order to enable non-AP MLD to request (current) AP MLD 1 to roam to (target) AP MLD 2, the embodiment of the present application proposes that the MLD MAC address in the Common Info field of the basic multi-link element in Figure 2K should indicate the MLD MAC address of (target) AP MLD 2. The contents indicated by the link ID information field, BSS parameter change count field, medium synchronization delay information field, EML capability field, MLD capability and operation field, AP MLD ID field, and extended MLD capability and operation field in the Common Info field of the basic multi-link element refer to the relevant information between non-AP MLD and (target) AP MLD 2 (specific content). content is consistent with the IEEE 802.11be standard).

The roaming information field in the Common Info field of the basic multi-link element is a new field added in the embodiment of the present application. The information indicated is similar to the roaming information field in the Common Info field of the aforementioned reconfiguration multi-link element, but the indicated meaning is different, as follows:

Channel and bandwidth: used to indicate the channel information supported by (target) AP MLD 2 (including channel bandwidth, primary channel number, secondary channel number, etc.).

RU Allocation: Used to indicate the RU information used by the non-AP MLD to communicate with the (target) AP MLD 2.

Power Limit: Used to indicate the transmit power information (such as maximum transmit power, minimum transmit power, etc.) used by the non-AP MLD initiating roaming to communicate with the (target) AP MLD 2.

Max TX/RX Nss: Used to indicate the maximum number of transmit or receive spatial streams supported by (target) AP MLD 2.

EDCA parameter set: used to indicate the EDCA parameter set supported by the non-AP MLD initiating roaming under (target) AP MLD 2.

EPCS information: used to indicate the EPCS capability information and/or subscription information supported by the non-AP MLD initiating roaming under (target) AP MLD 2. It can also be used for the non-AP MLD to establish EPCS priority access permission and EDCA parameter set for EPCS priority access with (target) AP MLD 2.

BSR related information: used to indicate the cache status information of the initiating (target) AP MLD 2.

SN: Used to indicate the sequence number between the non-AP MLD initiating roaming and the (target) AP MLD 2.

PN: Used to indicate the packet number (Packet Number) to be sent between the non-AP MLD initiating roaming and the (target) AP MLD 2.

BA session: used to indicate the BlockAck session information established between the non-AP MLD initiating roaming and the (target) AP MLD 2.

Multi-AP Mode: Used to indicate the multi-AP collaboration mode supported by (target) AP MLD 2, such as C-TDMA, C-OFDMA, C-SR, C-BF, J-TX, etc.

Power-related information: used to indicate the sleep policy information of the initiating (target) AP MLD 2, such as the sleep window information (sleep start time, sleep duration, sleep window interval, etc.) and/or the supported sleep mechanisms.

TWT element: Used to indicate the TWT information established between the non-AP MLD initiating roaming and the (target) AP MLD 2.

R-TWT SP: Used to indicate the R-TWT SP information established between the non-AP MLD initiating roaming and the (current) AP MLD 1.

TID-to-Link mapping: used to indicate the establishment of a TID-to-Link mapping scheme between the non-AP MLD initiating roaming and the (target) AP MLD 2.

Extended capability element: used to indicate the extended capability information of (target) AP MLD 2. For details, see the IEEE 802.11 baseline standard specification.

EHT capability element: used to indicate the extremely high throughput capability information of the (target) AP MLD 2. For details, see the IEEE 802.11be standard specification.

Figure 2L is a schematic diagram of the format of the Per-STA Profile subelement provided in an embodiment of the present application. The format of the Link Information field of the Basic Multilink element has been modified: if the "Link Information" field is present, it consists of one or more Per-STA Profile subelement(s) and other optional subelement(s). The format of the Per-STA Profile subelement is shown in Figure 2L.

The STA control field format of the basic multi-link element is shown in Figure 2M. The embodiment of the present application proposes that any one bit in B12 to B15 is defined as a roaming information presence field. The roaming information presence is used to indicate whether the STA information field of the basic multi-link element shown in Figure 2N has a roaming information field. For example, if the roaming information presence is equal to 0, it means that the STA information field of the basic multi-link element shown in Figure 2N does not have a roaming information field; if the roaming information presence is equal to 1, it means that the STA information field of the basic multi-link element shown in Figure 2N has a roaming information field.

The roaming information field carried in the STA information field of the basic multilink element in the link reconfiguration response frame is consistent with the aforementioned link reconfiguration The roaming information field is consistent with the roaming information field carried in the common information field (Common Info field) of the basic multilink element in the configuration response frame, and is not repeated here.

Note: Roaming information can exist in both the Common Info field and the STA information field of the basic multi-link element. In practice, roaming information only needs to exist in one of the two fields and does not need to be repeated.

Benefit of Example 1: Handover (roaming) from a non-AP MLD to the current AP MLD is initiated. The non-AP MLD is more aware of changes in communication link quality during mobility and can promptly initiate roaming based on its location and the signal quality between it and the current AP MLD, thus reducing roaming latency.

Example 2: (Method 2) The non-AP MLD requests roaming from the (target) AP MLD 2:

As shown in Method 2 in Figure 2B , the non-AP MLD can also directly send a Link Reconfiguration Request frame to (target) AP MLD 2 (on Link 1, Link 2, or Link 3, with Link 2 used as an example). If (target) AP MLD 2 successfully receives the frame, it can measure the frame's reception quality (RSSI, CSI, SINR, SNR, and other indicators) and decide whether to accept the non-AP MLD's roaming request based on the frame information and (target) AP MLD 2's own status. It then responds with a Link Reconfiguration Response frame to the non-AP MLD on the link that received the Link Reconfiguration Request frame. During this process, context migration is performed between (current) AP MLD 1 and (target) AP MLD 2. For details, see the design of some embodiments of this application.

The reception quality of the frame, for example, RSSI is greater than or equal to a first threshold (dBm). The first threshold may be a predefined threshold. The reception quality of the frame, for example, a related indicator of CSI is greater than or equal to a second threshold. The second threshold may be a predefined threshold. The reception quality of the frame, for example, SINR is greater than or equal to a third threshold (dB). The third threshold may be a predefined threshold. The reception quality of the frame, for example, SNR is greater than or equal to a fourth threshold (dB). The fourth threshold may be a predefined threshold. In some embodiments, the judgment threshold may also correspond to the result of a weighted summation of some or all of the above parameters, that is, pre-configuring influence weights for the relevant parameters, and comparing the weighted sum with the preset threshold.

Link reconfiguration request frame format design:

The Link Reconfiguration Request frame format for Mode 2 is the same as that for Mode 1. The difference is that in Mode 2, the frame is sent to (target) AP MLD 2, while in Mode 1, it is sent to (current) AP MLD 1, resulting in a different RA field. Additionally, some fields in the frame format indicate different content. For example, when the Reconfiguration Operation Type in the STA Control field format of the Reconfiguration Multi-Link element indicates (Sequence) 5, indicating a link switch mode, the Link ID field in the STA Control field format indicates the identifier of the newly established link, while the New Link Information field in the STA Information field of the Reconfiguration Multi-Link element indicates the identifier of the link to be disconnected from (current) AP MLD 1. The remaining content is consistent with the design for Mode 1 and is not further described.

Link reconfiguration response frame format design:

The link reconfiguration response frame format in mode 2 is the same as that in mode 1. The difference is that in mode 2, the frame is sent by (target) AP MLD 2 to non-AP MLD, while in mode 1, the frame is sent by (current) AP MLD 1 to non-AP MLD. Therefore, the TA field is different. The rest of the content is consistent with the design in mode 1 and will not be repeated here.

Benefit of Example 2: Handover (roaming) from a non-AP MLD to a target AP MLD is initiated. The non-AP MLD is more aware of changes in communication link quality during mobility and can promptly initiate roaming based on its location and channel status. The roaming initiation frame itself can also measure the signal quality between the non-AP MLD and the target AP MLD, saving additional link quality measurement time and reducing roaming latency.

FIG3A is a flow chart of a multi-link device roaming communication method provided by an embodiment of the present application. As shown in FIG3A , the multi-link device roaming communication method is executed on an access point multi-link device (AP MLD). The communication method includes at least one of the following operations: Operation 301A: A first access point multi-link device (AP MLD) 1 sends a first link reconfiguration frame to a non-AP MLD to initiate roaming. The first link reconfiguration frame is used to request the non-AP MLD to roam from AP MLD 1 to a second access point multi-link device (AP MLD) 2. Operation 302A: AP MLD 1 receives a second link reconfiguration frame sent by the non-AP MLD to obtain a roaming result.

Through the above technical solution, the AP MLD 1 sends a first link reconfiguration frame to the non-AP MLD to perform roaming. The operation is initiated, and the AP MLD 1 receives the second link reconfiguration frame sent by the non-AP MLD to obtain a roaming result, thereby improving the experience of the non-AP MLD when roaming to the AP MLD 2 and achieving substantially uninterrupted roaming.

In some embodiments of the present application, when the AP MLD 1 initiates a roaming operation or before the AP MLD 1 initiates a roaming operation, the AP MLD 1 performs context migration with the AP MLD 2. In some embodiments of the present application, the first link reconfiguration frame carries the status information of the AP MLD 2. In some embodiments of the present application, the communication method further includes the AP MLD 1 sending link reconfiguration confirmation information to the non-AP MLD. In some embodiments of the present application, the first link reconfiguration frame and the second link reconfiguration frame include one of the following combinations: a request to send RTS frame and a clear to send CTS frame, a probe request frame and a probe response frame, a multilink probe request frame and a multilink probe response frame, or a fast basic service set switching FT request frame and an FT response frame. In some embodiments of the present application, the first link reconfiguration frame includes a reconfiguration multilink element.

In some embodiments of the present application, the existence bit map subfield of the reconfigured multi-link element includes a multi-link device MLD media access control MAC address existence field, an enhanced multi-link EML capability existence field, an MLD capability and operation existence field, and/or a roaming information existence field, wherein: the MLD MAC address existence field is used to indicate whether the general information field of the reconfigured multi-link element has an MLD MAC address field; the EML capability existence field is used to indicate whether the general information field of the reconfigured multi-link element has an EML capability field; the MLD capability and operation existence field is used to indicate whether the general information field of the reconfigured multi-link element has an MLD capability and operation field; the roaming information existence field is used to indicate whether the general information field or link information field of the reconfigured multi-link element has a roaming information field. In some embodiments of the present application, the general information field of the reconfigured multi-link element includes an MLD MAC address field, an EML capability field, an MLD capability and operation field, and a roaming information field, wherein: the MLD MAC address field is used to indicate the MLD MAC address of the AP MLD 2; the EML capability field is used to indicate the enhanced multi-link information of the non-AP MLD; the MLD capability and operation field is used to indicate the multi-link capability information and operation parameters of the non-AP MLD; the roaming information field is used to indicate one or more of the following information: channel information, resource scheduling information, power information, maximum number of transmit/receive spatial streams, enhanced distributed channel access EDCA parameter set, emergency preparedness communication service EPCS information, buffer status report BSR information, sequence number SN, data packet number PN, block acknowledgment BA session information, multi-access point AP mode, power information, target wake-up time TWT information, target wake-up time service phase R-TWT SP information, service identifier to link TID-to-Link mapping, extended capability information, and extremely high throughput EHT capability information.

In some embodiments of the present application, the channel information is used to indicate the channel information supported by the non-AP MLD and/or the channel information corresponding to the link established by the non-AP MLD; the resource scheduling information is used to indicate the resource unit RU information used by the non-AP MLD to communicate with the AP MLD 1; the power information is used to indicate the transmit power information used by the non-AP MLD to communicate with the AP MLD 1; the maximum number of transmit/receive spatial streams is used to indicate the maximum number of transmit/receive spatial streams supported by the non-AP MLD; the enhanced distributed channel access EDCA parameter set is used to indicate the EDCA parameter set supported by the non-AP MLD or to indicate the EDCA parameter set established by the non-AP MLD and the AP MLD 1; the emergency preparedness communication service EPCS information is used to indicate the EPCS capability information, EPCS subscription information and EPCS activation status information supported by the non-AP MLD, and/or to indicate the non-AP MLD requesting communication with the AP MLD 2. Establishing an EPCS priority access grant and an EDCA parameter set for EPCS priority access; the buffer status report (BSR) information is used to indicate the buffer status information of the non-AP MLD; the sequence number (SN) is used to indicate the SN of the frame between the non-AP MLD and the AP MLD 1; the packet number (PN) is used to indicate the PN that has been sent, is about to be sent, or has not been sent between the non-AP MLD and the AP MLD 1; the block acknowledgement (BA) session information is used to indicate the block acknowledgement session information established between the non-AP MLD and the AP MLD 1; the multi-access point (AP) mode is used to indicate the multi-AP cooperation mode supported by the non-AP MLD; the power information is used to indicate the sleep policy information and/or supported sleep mechanism of the non-AP MLD; the target wake-up time (TWT) information is used to indicate the TWT information established between the non-AP MLD and the AP MLD 1; the target wake-up time service phase (R-TWT) SP information is used to indicate the R-TWT established between the non-AP MLD and the AP MLD 1. SP information; the mapping of the service identifier to the link TID-to-Link is used to indicate the TID-to-Link mapping scheme established between the non-AP MLD and the AP MLD 1, or to indicate the non-AP MLD request and the AP The TID-to-Link mapping scheme of the link established between MLD 2; the extended capability information is used to indicate the extended capability information of the non-AP MLD; the extremely high throughput EHT capability information is used to indicate the EHT capability information of the non-AP MLD.

In some embodiments of the present application, the reconfiguration multi-link element includes a per-site summary sub-element for carrying summary information of the non-AP MLD that initiated roaming. In some embodiments of the present application, the per-site summary sub-element includes a STA control field, and the STA control field includes a link identifier ID field, a reconfiguration operation type field, a new link ID exists field, and/or a roaming information exists field, wherein: the link ID field is used to indicate the link ID; the new link ID exists field is used to indicate whether a new link ID information field exists in the STA information field of the reconfiguration multi-link element; and the roaming information exists field is used to indicate whether a roaming information field exists in the link information field of the reconfiguration multi-link element.

In some embodiments of the present application, when the value indicated by the Reconfiguration Operation Type field is 5, the Reconfiguration Operation Type field is set to the meaning/operation of switching links. In some embodiments of the present application, when the Reconfiguration Operation Type field indicates the Switch Link field and/or the New Link ID Existence field of the STA Control field indicates presence, the Link ID field in the STA Control field indicates the ID of the link disconnected between the non-AP MLD and AP MLD 1, and the New Link ID Information field indicates the ID of the link established between the non-AP MLD and AP MLD 2. In some embodiments of the present application, when the Reconfiguration Operation Type field indicates the Switch Link field and/or the New Link ID Existence field of the STA Control field indicates presence, the Link ID field in the STA Control field indicates the ID of the link established between the non-AP MLD and AP MLD 2, and the New Link ID Information field indicates the ID of the link disconnected between the non-AP MLD and AP MLD 1. In some embodiments of the present application, the new link ID information field includes a link ID field, which is used to indicate an identifier of the link, wherein the new link ID information field also includes a link ID extension field, and the link ID field and the link ID extension field jointly indicate a new link ID established between the non-AP MLD and the AP MLD 2.

In some embodiments of the present application, the second link reconfiguration frame includes a reconfiguration status list field. In some embodiments of the present application, the reconfiguration status list field includes one or more reconfiguration status dual subfields, each of which includes a link ID information field and a status field. In some embodiments of the present application, the link ID information field includes a link ID subfield, each of which indicates a link ID of an AP, and indicates whether the link ID of the AP is added or deleted in the first link reconfiguration frame. In some embodiments of the present application, the status field includes a first status code, a second status code, a third status code, a fourth status code, and/or a fifth status code, wherein the first status code is used to indicate that the roaming request is rejected because the BSS load of the AP MLD 2 is greater than a first set value, the second status code is used to indicate that the roaming request is rejected because the channel load for establishing a link is greater than a second set value, the third status code is used to indicate that the roaming request is rejected because the time for requesting to establish a link does not match the window in which the AP MLD 2 is allowed to establish a link, the fourth status code is used to indicate that the roaming request will enter a sleep state and will not accept roaming requests for the time being, and the fifth status code is used to indicate that the roaming request is rejected because the AP MLD 2 has reached the maximum number of supported STAs/non-AP MLDs.

In some embodiments of the present application, the second link reconfiguration frame further includes a basic multilink element, wherein the presence bitmap field of the basic multilink element includes a roaming information presence field, wherein the roaming information presence field is used to indicate whether a roaming information field exists in the general information field or link information field of the basic multilink element. In some embodiments of the present application, the general information field of the basic multilink element includes an MLD MAC address field, which is used to indicate the MLD MAC address of AP MLD 2. In some embodiments of the present application, the general information field of the basic multilink element further includes a link ID information field, a BSS parameter change count field, a media synchronization delay information field, an EML capability field, an MLD capability and operation field, an AP MLD ID field, and/or an extended MLD capability and operation field, wherein the link ID information field, the BSS parameter change count field, the media synchronization delay information field, the EML capability field, the MLD capability and operation field, the AP MLD ID field, and/or the extended MLD capability and operation field indicate related information between the non-AP MLD and AP MLD 2.

In some embodiments of the present application, the roaming information field is used to indicate one or more of the following information: channel information, resource scheduling information, power information, maximum number of transmit/receive spatial streams, EDCA parameter set, EPCS information, BSR information, SN, PN, BA session information, multi-AP mode, power information, TWT information, R-TWT SP information, TID-to-Link mapping, extended capability information, and EHT capability information, wherein: the channel information is used to indicate the channel information supported by the non-AP MLD and/or channel information corresponding to the link established by the non-AP MLD; the resource scheduling information is used to indicate RU information used by the non-AP MLD to communicate with the AP MLD 1; the power information is used to indicate transmit power information used by the non-AP MLD to communicate with the AP MLD 1; the maximum number of transmit/receive spatial streams is used to indicate the maximum number of transmit/receive spatial streams supported by the non-AP MLD; the EDCA parameter set is used to indicate the EDCA parameter set supported by the non-AP MLD or to indicate the EDCA parameter set established between the non-AP MLD and the AP MLD 1; the EPCS information is used to indicate EPCS capability information, EPCS subscription information, and EPCS activation status information supported by the non-AP MLD, and/or to indicate the EDCA parameter set for the non-AP MLD to request to establish EPCS priority access permission and EPCS priority access with the AP MLD 2; the BSR information is used to indicate cache status information of the non-AP MLD; and the SN is used to indicate the cache status information of the non-AP MLD and the AP MLD 1; the PN is used to indicate the PN that has been sent between the non-AP MLD and the AP MLD 1, or the PN that is about to be sent, or the PN that has not been sent; the BA session information is used to indicate the block confirmation session information established by the non-AP MLD and the AP MLD 1; the multi-AP mode is used to indicate the multi-AP cooperation mode supported by the non-AP MLD; the power information is used to indicate the sleep policy information and/or the supported sleep mechanism of the non-AP MLD; the TWT information is used to indicate the TWT information established between the non-AP MLD and the AP MLD 1; the R-TWT SP information is used to indicate the R-TWT SP information established between the non-AP MLD and the AP MLD 1; the TID-to-Link mapping is used to indicate the TID-to-Link mapping scheme established between the non-AP MLD and the AP MLD 1, or for indicating the non-AP MLD request and the AP MLD 2; the extended capability information is used to indicate the extended capability information of the non-AP MLD; the EHT capability information is used to indicate the EHT capability information of the non-AP MLD.

In some embodiments of the present application, the link information field of the basic multi-link element includes a per-site overview sub-element, the per-site overview sub-element includes an STA control field, and the STA control field includes a roaming information presence field. In some embodiments of the present application, the roaming information presence field is used to indicate whether a roaming information field exists in the link information field of the basic multi-link element. In some embodiments of the present application, the communication method further includes the AP MLD 1 starting a timer to confirm the time interval between the AP MLD 1 sending the first link reconfiguration frame and the AP MLD 1 receiving the second link reconfiguration frame. In some embodiments of the present application, after the AP MLD 1 sends the first link reconfiguration frame, the timer is started. If the AP MLD 1 receives the second link reconfiguration frame within the time corresponding to the timer, the AP MLD 1 determines whether to roam based on the second link reconfiguration frame. In some embodiments of the present application, after the AP MLD 1 sends the first link reconfiguration frame, the timer is started. If the AP MLD 1 does not receive the second link reconfiguration frame within the time corresponding to the timer, the AP MLD 1 determines that the roaming has failed.

Example 3: Method for the current AP MLD to initiate roaming:

As shown in Figure 3B , when (current) AP MLD 1 proactively initiates roaming for a non-AP MLD, this indicates that the link quality between the non-AP MLD and (current) AP MLD 1 is poor, or (current) AP MLD 1 measures that the non-AP MLD is moving away from (current) AP MLD 1 (approaching (target) AP MLD 2). Therefore, when (current) AP MLD 1 initiates roaming for the non-AP MLD, or before initiating roaming for the non-AP MLD, AP MLD 1 first performs context migration with (target) AP MLD 2 (see some embodiments of this application for details).

The steps for (current) AP MLD 1 to initiate roaming (for non-AP MLD) are as follows:

Step 1: (Current) AP MLD 1 sends a Link Reconfiguration Request frame to the non-AP MLD (on link 1), which may also carry information about the recommended (target) AP MLD 2.

Step 2 (optional): If the non-AP MLD has not previously obtained the link status information between it and (target) AP MLD 2, it can send a request frame 1 to (target) AP MLD 2 on the link to be established after roaming (link 2 is used as an example in the figure); if the non-AP MLD has previously obtained the link status information between it and (target) AP MLD 2, it does not need to send this frame.

Step 3 (optional): If target AP MLD 2 receives the request frame 1 sent by the non-AP MLD in step 2, it replies with a response frame 1 to the non-AP MLD on the link that received the request frame 1. The non-AP MLD determines whether to roam to target AP MLD 2 based on the quality of the received response frame 1 (such as RSSI, CSI, SINR, SNR, etc.).

Note: Similar to some of the above embodiments, the request frame 1 and the response frame 1 can be one of the following combinations:

The request frame 1 is an RTS frame, and the response frame 1 is a CTS frame.

The request frame 1 is a probe request frame, and the response frame 1 is a probe response frame.

The request frame 1 is a multi-link detection request frame, and the response frame 1 is a multi-link detection response frame.

The request frame 1 is an FT request frame, and the response frame 1 is an FT response frame.

The quality of the received response frame 1, for example, RSSI is greater than or equal to the first threshold (dBm). The first threshold may be a predefined threshold. The quality of the received response frame 1, for example, the relevant index of CSI is greater than or equal to the second threshold. The second threshold may be a predefined threshold. The quality of the received response frame 1, for example, SINR is greater than or equal to the third threshold (dB). The third threshold may be a predefined threshold. The quality of the received response frame 1, for example, SNR is greater than or equal to the fourth threshold (dB). The fourth threshold may be a predefined threshold. In some embodiments, the judgment threshold may also correspond to the result of the weighted summation of some or all of the above parameters, that is, the influence weights are preconfigured for the relevant parameters, and the weighted sum is compared with the preset threshold.

In addition, if the non-AP MLD does not send a request frame 1 to the target AP MLD 2, the target AP MLD 2 can proactively send a response frame 1 to the non-AP MLD. The non-AP MLD determines whether to roam to the target AP MLD 2 based on the quality of the received response frame 1 (such as RSSI, CSI, SINR, SNR, etc.). In this case, the response frame 1 can be a beacon frame.

The quality of the received response frame 1, for example, RSSI is greater than or equal to the first threshold (dBm). The first threshold may be a predefined threshold. The quality of the received response frame 1, for example, the relevant index of CSI is greater than or equal to the second threshold. The second threshold may be a predefined threshold. The quality of the received response frame 1, for example, SINR is greater than or equal to the third threshold (dB). The third threshold may be a predefined threshold. The quality of the received response frame 1, for example, SNR is greater than or equal to the fourth threshold (dB). The fourth threshold may be a predefined threshold. In some embodiments, the judgment threshold may also correspond to the result of the weighted summation of some or all of the above parameters, that is, the influence weights are preconfigured for the relevant parameters, and the weighted sum is compared with the preset threshold.

Step 4: The non-AP MLD (on link 1) responds with a link reconfiguration response frame to the (current) AP MLD 1 to indicate whether it accepts the roaming request and what parameters/information it accepts.

Note: (Current) AP MLD 1 may perform context migration again with (target) AP MLD 2 based on the information sent by the received non-AP MLD in the link reconfiguration response frame to determine the final parameters/information after the non-AP MLD switches to the (target) AP MLD 2.

Step 5 (optional): Since the information contained in the Link Reconfiguration Request frame initiated by (current) AP MLD 1 in step 1 was only partially adopted by the non-AP MLD (or the non-AP MLD recommended new parameters) and fed back through the Link Reconfiguration Response frame in step 4, (current) AP MLD 1 still needs to confirm the final link information/parameter information established at this time, so it sends a Link Reconfiguration Confirm frame to the non-AP MLD (on link 1).

NOTE: If the non-AP MLD fully adopts the parameters/configuration given in step 1 in step 4, then (current) AP MLD 1 does not need to send a link reconfiguration confirmation frame to the non-AP MLD.

Link reconfiguration request frame format design:

The Link Reconfiguration Request frame format in this embodiment is the same as that in Example 1. The difference is that in this embodiment, the Link Reconfiguration Request frame is sent from (current) AP MLD 1 to the non-AP MLD, so the TA and RA fields are different. The remaining fields and their corresponding meanings are detailed in the design of Example 1 and are not repeated here. The difference from Example 1 is that the fields in this frame format indicate the content corresponding to (target) AP MLD 2.

Link reconfiguration response frame format design:

The Link Reconfiguration Response frame format in this embodiment is the same as that in Example 1, except that in this embodiment, the Link Reconfiguration Response frame is sent by the non-AP MLD to (current) AP MLD 1, resulting in different TA and RA fields. The remaining fields and their corresponding meanings are detailed in Example 1 and are not further described. Unlike Example 1, the fields in this frame format indicate information between the non-AP MLD and (target) AP MLD 2, and indicate parameters/configuration information accepted by the non-AP MLD or parameters/configuration information recommended by the non-AP MLD.

Link Reconfiguration Confirm frame format design:

The format of the Link Reconfiguration Confirm frame in this embodiment is the same as that of the Link Reconfiguration Response frame in Example 1. The difference is that the Link Reconfiguration Confirm frame in this embodiment is sent by (current) AP MLD 1 to non-AP MLD, so the TA and RA fields are different. The remaining fields are the same as those in the corresponding The meaning is detailed in the design of Example 1 and will not be repeated here. The difference from the link reconfiguration response frame of Example 1 is that the fields in this frame format indicate the information between the non-AP MLD and the (target) AP MLD 2, and indicate the parameters/configuration information finally determined by the (target) AP MLD 2 based on the link reconfiguration response frame sent by the non-AP MLD. The difference is that the MLD MAC address in the Common Info field format of the basic multi-link element in Figure 2K is filled with the MAC address of the (target) AP MLD 2 instead of the MAC address of the (current) AP MLD 1. Therefore, the non-AP MLD can know that the parameters/configuration indicated in this link reconfiguration response frame are those of the (target) AP MLD 2.

Benefits of Example 3: Handover (roaming) from the current AP MLD to the non-AP MLD is initiated. The current AP MLD can promptly learn the link quality between the current and non-AP MLD while receiving data/signals from the non-AP MLD, helping the non-AP MLD initiate roaming. This allows the current AP MLD to initiate roaming earlier than the non-AP MLD, reducing roaming latency. Furthermore, when the current AP MLD is heavily loaded, the current AP MLD can, based on environmental information (e.g., the non-AP MLD's channel state information, target AP MLD load information, etc.), ensure that the non-AP MLD is served by a more appropriate target AP MLD (with a lighter load), achieving load balancing to a certain extent.

FIG4A is a flow chart of a multi-link device roaming communication method provided by an embodiment of the present application. As shown in FIG4A , the multi-link device roaming communication method is executed on an access point multi-link device (AP MLD). The communication method includes at least one of the following operations: Operation 401A: The second access point multi-link device (AP MLD) 2 sends a first link reconfiguration frame to a non-AP MLD to initiate roaming. The first link reconfiguration frame is used to request the non-AP MLD to roam from the first access point multi-link device (AP MLD) 1 to the AP MLD 2. Operation 402A: The AP MLD 2 receives the second link reconfiguration frame sent by the non-AP MLD to obtain a roaming result.

Through the above technical solution, the AP MLD 2 sends a first link reconfiguration frame to the non-AP MLD to initiate roaming, and the AP MLD 2 receives a second link reconfiguration frame sent by the non-AP MLD to obtain the roaming result, thereby improving the experience of the non-AP MLD when roaming on the AP MLD 2 and achieving basically uninterrupted roaming.

In some embodiments of the present application, when AP MLD 2 initiates roaming or before AP MLD 2 initiates roaming, AP MLD 2 performs context migration with AP MLD 1. In some embodiments of the present application, AP MLD 2 sends the first link reconfiguration frame to the non-AP MLD to request link switching. The first link reconfiguration frame includes information about disconnecting the link between the non-AP MLD and AP MLD 1 and establishing a link between the non-AP MLD and AP MLD 2. In some embodiments of the present application, AP MLD 2 sends the first link reconfiguration frame to the non-AP MLD to request adding a link. The first link reconfiguration frame includes information about establishing a link between the non-AP MLD and AP MLD 2. In some embodiments of the present application, the first link reconfiguration frame and the second link reconfiguration frame include one of the following combinations: a request to send (RTS) frame and a clear to send (CTS) frame, a probe request frame and a probe response frame, a multilink probe request frame and a multilink probe response frame, or a fast basic service set switching (FT) request frame and a fast basic service set switching (FT) response frame. In some embodiments of the present application, the first link reconfiguration frame includes a reconfiguration multilink element.

In some embodiments of the present application, the existence bit map subfield of the reconfigured multi-link element includes a multi-link device MLD media access control MAC address existence field, an enhanced multi-link EML capability existence field, an MLD capability and operation existence field, and/or a roaming information existence field, wherein: the MLD MAC address existence field is used to indicate whether the general information field of the reconfigured multi-link element has an MLD MAC address field; the EML capability existence field is used to indicate whether the general information field of the reconfigured multi-link element has an EML capability field; the MLD capability and operation existence field is used to indicate whether the general information field of the reconfigured multi-link element has an MLD capability and operation field; the roaming information existence field is used to indicate whether the general information field or link information field of the reconfigured multi-link element has a roaming information field.

In some embodiments of the present application, the general information field of the reconfigured multi-link element includes an MLD MAC address field, an EML capability field, an MLD capability and operation field, and a roaming information field, wherein: the MLD MAC address field is used to indicate the MLD MAC address of the AP MLD 2; the EML capability field is used to indicate the enhanced multi-link information of the non-AP MLD; the MLD capability and operation field is used to indicate the multi-link capability information and operation parameters of the non-AP MLD; the roaming information field is used to indicate one or more of the following information: channel information, resource scheduling information, power information, maximum number of transmit/receive spatial streams, enhanced distributed channel access EDCA parameter set, emergency preparedness communication service EPCS information, buffer status report BSR information, sequence number SN, data packet number PN, block acknowledgment BA session information, multi-access point AP mode, power information, target wake-up time TWT information, target wake-up time service phase R-TWT SP information, service identifier to link TID-to-Link mapping, extended capability information, and extremely high throughput EHT capability information.

In some embodiments of the present application, the channel information is used to indicate the channel information supported by the non-AP MLD and/or the channel information corresponding to the link established by the non-AP MLD; the resource scheduling information is used to indicate the resource unit RU information used by the non-AP MLD to communicate with the AP MLD 1; the power information is used to indicate the transmission power information used by the non-AP MLD to communicate with the AP MLD 1; the maximum number of transmit/receive spatial streams is used to indicate the maximum number of transmit/receive spatial streams supported by the non-AP MLD; the enhanced distributed channel access EDCA parameter set is used to indicate the number of transmit/receive spatial streams supported by the non-AP MLD. The EDCA parameter set may be used to indicate the EDCA parameter set established between the non-AP MLD and the AP MLD 1; the emergency preparedness communication service EPCS information may be used to indicate the EPCS capability information, EPCS subscription information and EPCS activation status information supported by the non-AP MLD, and/or may be used to indicate the EDCA parameter set that the non-AP MLD requests to establish an EPCS priority access permission and EPCS priority access with the AP MLD 2; the buffer status report BSR information may be used to indicate the buffer status information of the non-AP MLD; the sequence number SN may be used to indicate the SN of the frame between the non-AP MLD and the AP MLD 1; The data packet number PN is used to indicate the PN that has been sent between the non-AP MLD and the AP MLD 1, or the PN that is about to be sent, or the PN that has not been sent; the block acknowledgment BA session information is used to indicate the block acknowledgment session information established between the non-AP MLD and the AP MLD 1; the multi-access point AP mode is used to indicate the multi-AP collaboration mode supported by the non-AP MLD; the power information is used to indicate the sleep policy information and/or the supported sleep mechanism of the non-AP MLD; the target wake-up time TWT information is used to indicate the TWT information established between the non-AP MLD and the AP MLD 1; the limited target wake-up time The service phase R-TWT SP information is used to indicate the R-TWT SP information established between the non-AP MLD and the AP MLD 1; the service identifier to link TID-to-Link mapping is used to indicate the TID-to-Link mapping scheme established between the non-AP MLD and the AP MLD 1, or used to indicate the TID-to-Link mapping scheme of the link established between the non-AP MLD request and the AP MLD 2; the extended capability information is used to indicate the extended capability information of the non-AP MLD; the extremely high throughput EHT capability information is used to indicate the EHT capability information of the non-AP MLD.

In some embodiments of the present application, the reconfiguration multilink element includes a per-site summary sub-element for carrying summary information of the non-AP MLD that initiated roaming. In some embodiments of the present application, the per-site summary sub-element includes a STA control field, and the STA control field includes a link identifier ID field, a reconfiguration operation type field, a new link ID presence field, and/or a roaming information presence field, wherein: the link ID field is used to indicate the link ID; the new link ID presence field is used to indicate whether a new link ID information field exists in the STA information field of the reconfiguration multilink element; and the roaming information presence field is used to indicate whether a roaming information field exists in the link information field of the reconfiguration multilink element. In some embodiments of the present application, when the value indicated by the reconfiguration operation type field is 5, the reconfiguration operation type field is set to the meaning/operation of switching links.

In some embodiments of the present application, when the reconfiguration operation type field indicates the switch link field and/or the new link ID existence field of the STA control field indicates existence, the link ID field in the STA control field indicates the link ID of the link between the non-AP MLD and the AP MLD 1 being disconnected, and the new link ID information field indicates the link ID of the link established between the non-AP MLD and the AP MLD 2. In some embodiments of the present application, when the reconfiguration operation type field indicates the switch link field and/or the new link ID existence field of the STA control field indicates existence, the link ID field in the STA control field indicates the link ID of the link established between the non-AP MLD and the AP MLD 2, and the new link ID information field indicates the link ID of the link disconnected between the non-AP MLD and the AP MLD 1. In some embodiments of the present application, the new link ID information field includes a link ID field, which is used to indicate an identifier of the link, wherein the new link ID information field also includes a link ID extension field, and the link ID field and the link ID extension field jointly indicate a new link ID established between the non-AP MLD and the AP MLD 2.

In some embodiments of the present application, the second link reconfiguration frame includes a reconfiguration status list field. In some embodiments of the present application, the reconfiguration status list field includes one or more reconfiguration status dual subfields, and the reconfiguration status dual subfield includes a link ID information field and a status field. In some embodiments of the present application, the link ID information field includes a link ID subfield, and the link ID subfield indicates the link ID of the AP, and indicates the addition or deletion of the link ID of the AP in the first link reconfiguration frame. In some embodiments of the present application, the status field includes a first status code, a second status code, a third status code, a fourth status code, and/or a fifth status code, wherein the first status code is used to indicate that the roaming request is rejected because the The BSS load of the AP MLD 2 is greater than a first set value, the second status code is used to indicate that the roaming request is rejected because the channel load for establishing the link is greater than the second set value, the third status code is used to indicate that the roaming request is rejected because the time for requesting to establish the link does not match the window allowed for link establishment by the AP MLD 2, the fourth status code is used to indicate that the AP will enter a dormant state and will not accept the roaming request for the time being, and the fifth status code is used to indicate that the roaming request is rejected because the AP MLD 2 has reached the maximum number of STAs/non-AP MLDs supported. In some embodiments of the present application, the second link reconfiguration frame further includes a basic multilink element, the presence bitmap field of the basic multilink element includes a roaming information presence field, wherein the roaming information presence field is used to indicate whether a roaming information field exists in the general information field or the link information field of the basic multilink element.

In some embodiments of the present application, the general information field of the basic multi-link element includes an MLD MAC address field, which is used to indicate the MLD MAC address of the AP MLD 2. In some embodiments of the present application, the general information field of the basic multi-link element also includes a link ID information field, a BSS parameter change count field, a media synchronization delay information field, an EML capability field, an MLD capability and operation field, an AP MLD ID field, and/or an extended MLD capability and operation field, and the contents indicated by the link ID information field, the BSS parameter change count field, the media synchronization delay information field, the EML capability field, the MLD capability and operation field, the AP MLD ID field, and/or the extended MLD capability and operation field refer to related information between the non-AP MLD and the AP MLD 2. In some embodiments of the present application, the roaming information field is used to indicate one or more of the following information: channel information, resource scheduling information, power information, maximum number of transmit/receive spatial streams, EDCA parameter set, EPCS information, BSR information, SN, PN, BA session information, multi-AP mode, power information, TWT information, R-TWT SP information, TID-to-Link mapping, extended capability information, and EHT capability information, wherein: the channel information is used to indicate the channel information supported by the non-AP MLD and/or the channel information corresponding to the link established by the non-AP MLD; the resource scheduling information is used to indicate the RU information used by the non-AP MLD to communicate with the AP MLD 1; the power information Used to indicate the transmit power information used by the non-AP MLD to communicate with the AP MLD 1; the maximum number of transmit/receive spatial streams is used to indicate the maximum number of transmit/receive spatial streams supported by the non-AP MLD; the EDCA parameter set is used to indicate the EDCA parameter set supported by the non-AP MLD or to indicate the EDCA parameter set established between the non-AP MLD and the AP MLD 1; the EPCS information is used to indicate the EPCS capability information, EPCS subscription information and EPCS activation status information supported by the non-AP MLD, and/or to indicate that the non-AP MLD requests to establish EPCS priority access permission and EPCS priority access with the AP MLD 2 EDCA parameter set; the BSR information is used to indicate the cache status information of the non-AP MLD; the SN is used to indicate the SN of the frame between the non-AP MLD and the AP MLD 1; the PN is used to indicate the PN that has been sent, the PN that is about to be sent, or the PN that has not been sent between the non-AP MLD and the AP MLD 1; the BA session information is used to indicate the block confirmation session information established between the non-AP MLD and the AP MLD 1; the multi-AP mode is used to indicate the multi-AP cooperation mode supported by the non-AP MLD; the power information is used to indicate the sleep policy information and/or the supported sleep mechanism of the non-AP MLD; the TWT information is used to indicate The TWT information established between the non-AP MLD and the AP MLD 1; the R-TWT SP information is used to indicate the R-TWT SP information established between the non-AP MLD and the AP MLD 1; the TID-to-Link mapping is used to indicate the TID-to-Link mapping scheme established between the non-AP MLD and the AP MLD 1, or to indicate the TID-to-Link mapping scheme of the link established between the non-AP MLD request and the AP MLD 2; the extended capability information is used to indicate the extended capability information of the non-AP MLD; the EHT capability information is used to indicate the EHT capability information of the non-AP MLD.

In some embodiments of the present application, the link information field of the basic multilink element includes a per-site summary sub-element, the per-site summary sub-element includes an STA control field, and the STA control field includes a roaming information presence field. In some embodiments of the present application, the roaming information presence field is used to indicate whether a roaming information field exists in the link information field of the basic multilink element. In some embodiments of the present application, the communication method further includes the AP MLD 2 starting a timer to confirm the time interval between the AP MLD 2 sending the first link reconfiguration frame and the AP MLD 2 receiving the second link reconfiguration frame. In some embodiments of the present application, after the AP MLD 2 sends the first link reconfiguration frame, the timer is started. If the AP MLD 2 receives the second link reconfiguration frame within the time corresponding to the timer, the AP MLD 2 determines whether to roam based on the second link reconfiguration frame. In some embodiments of the present application, after the AP MLD 2 sends the first link reconfiguration frame, the timer is started. If the AP MLD 2 does not receive the second link reconfiguration frame within the time corresponding to the timer, the AP MLD 2 determines whether to roam. Upon receiving the second link reconfiguration frame, the AP MLD 2 determines that roaming fails.

Example 4: Method for target AP MLD to initiate roaming:

As shown in Figure 4B, when (target) AP MLD 2 proactively initiates roaming for the non-AP MLD, this indicates that the link quality between the non-AP MLD and the (current) AP MLD 1 is poor, or that (target) AP MLD 2 measures (i.e., the interaction of request frame 1 and/or response frame 1 in the figure) and learns that the non-AP MLD is moving away from the (current) AP MLD 1 and closer to the (target) AP MLD 2. The specific frames represented by request frame 1 and response frame 1 are shown in the design of Example 1. Therefore, when (target) AP MLD 2 initiates roaming (for the non-AP MLD), or before initiating roaming (for the non-AP MLD), it first performs context migration with the (current) AP MLD 1 (see some embodiments of this application for details).

There are three ways for (target) AP MLD 2 to initiate roaming to a non-AP MLD:

Method 1: (Target) AP MLD 2 requests to switch links with non-AP MLD:

In mode 1, the link reconfiguration request frame format sent by (target) AP MLD 2 on link 2' to be established is consistent with the link reconfiguration request frame format in Example 1. The reconfiguration operation type in the STA Control field of the Reconfiguration Multi-Link element is set to (order) 5, indicating the link switching type. Therefore, the New Link ID field in the STA Control field must be set to 1, which means that the STA Information field (see FIG. 2G ) of the Reconfiguration Multi-Link element contains new link ID information (the specific format is shown in FIG. 2H ). At this time, the Link ID field in the STA Control field of the Reconfiguration Multi-Link element indicates the link ID of the link to be disconnected from (current) AP MLD 1, and the New Link ID field (the specific format is shown in FIG. 2H ) in the STA Information field of the Reconfiguration Multi-Link element indicates the link ID of the link to be established with (target) AP MLD 2. The remaining fields are similar to the previous design and will not be repeated here.

The non-AP MLD then replies with a link reconfiguration response frame to the (target) AP MLD 2 on the link where the link reconfiguration request frame was received. The fields of this frame are similar to the previous design and will not be repeated here.

Method 2: (Target) AP MLD 2 requests to add a link (add link) with non-AP MLD, and then non-AP MLD requests to delete a link (delete link) with (current) AP MLD 1:

In mode 2, the link reconfiguration request frame format sent by (target) AP MLD 2 to the non-AP MLD on link 2' to be established, and the link reconfiguration request frame format sent by the non-AP MLD to the (current) AP MLD 1 on link 1, can be in the link reconfiguration request frame format specified in the IEEE 802.11be standard or in the link reconfiguration request frame format specified in Example 1. The specific operations in this mode are as follows:

First, (target) AP MLD 2 sends a link reconfiguration request frame to the non-AP MLD on the link 2’ to be established, in which the reconfiguration operation type (Reconfiguration Operation Type) in the STA control field of the reconfiguration multi-link element (Reconfiguration Multi-Link element) is set to (order) 2, that is, the type of adding a link (Add Link). Then the link ID field of the STA control field is set to the identifier of the new link requested by (target) AP MLD 2 to establish a new link with the non-AP MLD; the non-AP MLD replies with a link reconfiguration response frame to the (target) AP MLD 2 on the link on which it receives the link reconfiguration request frame, indicating whether it accepts the newly established link and other information.

Then, the non-AP MLD sends a Link Reconfiguration Request frame to the (current) AP MLD 1 on link 1, in which the Reconfiguration Operation Type in the STA Control field of the Reconfiguration Multi-Link element is set to (order) 3, that is, the type of Delete Link. Then, the Link ID field of the STA Control field is set to the identifier of the link that the non-AP MLD requests to be deleted by the (current) AP MLD 1; the (current) AP MLD 1 replies with a Link Reconfiguration Response frame to the non-AP MLD on the link on which it received the Link Reconfiguration Request frame, indicating the result of the link deletion and other information.

The remaining fields of the link reconfiguration request frame and the link reconfiguration response frame are similar to the previous design and will not be repeated here.

Method 3: (Target) AP MLD 2 requests to add a link with non-AP MLD, and then (current) AP MLD 1 requests to delete a link with non-AP MLD: In this case, a backhaul connection can be established between AP MLD 1 and AP MLD 2 during the context migration operation, so AP MLD 1 can know that AP MLD 2 and Non-AP MLD are making roaming requests, and thus make a request to delete the link.

In mode 3, the exchange of link reconfiguration request frames and link reconfiguration response frames between (target) AP MLD 2 and non-AP MLD, as well as the resulting effects, are consistent with those in mode 2 in the above implementation and will not be described in detail. The difference is that mode 3 is (current) AP MLD 1 proactively requests to disconnect the link with the non-AP MLD. The details are as follows:

(Current) AP MLD 1 sends a Link Reconfiguration Request frame to the non-AP MLD, in which the Reconfiguration Operation Type in the STA Control field of the Reconfiguration Multi-Link element is set to (Sequence) 3, that is, the type of Delete Link. Then the Link ID field of the STA Control field is set to the identifier of the link that (Current) AP MLD 1 requests the non-AP MLD to delete. The non-AP MLD replies with a Link Reconfiguration Response frame to the (Current) AP MLD 1 to indicate the result of the link deletion and other information.

The remaining fields of the link reconfiguration request frame and the link reconfiguration response frame are similar to the previous design and will not be repeated here.

Benefit of Example 4: The target AP MLD initiates a (roaming) AP MLD handover to the non-AP MLD. The target AP MLD can directly carry the configuration/parameters to be generated in the roaming request frame. Communication-related parameters can be configured during the new link establishment process, saving roaming time.

Timer design between link reconfiguration request frame and link reconfiguration response frame:

Embodiments 1 to 4 design a roaming method based on a link reconfiguration request frame and a link reconfiguration response frame. In order to prevent the roaming execution process from being too long and affecting the normal communication of the non-AP MLD and/or (current) AP MLD 1 and/or (target) AP MLD 2, the embodiments of the present application propose to design a roaming timer. The timer is used to constrain the time interval between the sender sending the link reconfiguration request frame and the responder sending the link reconfiguration response frame. For example, after the sender sends the link reconfiguration request frame, the countdown of the roaming timer is immediately started. If the link reconfiguration response frame sent by the responder is received within the time corresponding to the roaming timer, the sender determines whether the roaming (or link switching) is completed according to the instructions of the link reconfiguration response frame. If the link reconfiguration response frame sent by the responder is not received within the time corresponding to the roaming timer, the sender considers that the roaming (or link switching) has failed. If the roaming operation needs to be continued, the sender can wait and try again or find another target) AP MLD to roam.

FIG5A is a flow chart illustrating a communication method for a context migration method based on multi-link device roaming provided by an embodiment of the present application. As shown in FIG5A , the context migration method based on multi-link device roaming is executed on an access point multi-link device (AP MLD). The context migration method includes at least one of the following operations: Operation 501A: A first access point multi-link device (AP MLD) 1 establishes a backhaul link with a second access point multi-link device (AP MLD) 2; Operation 502A: AP MLD 1 exchanges context migration information with AP MLD 2 via the backhaul link.

Through the above technical solution, the AP MLD 1 exchanges context migration information with the AP MLD 2 through the backhaul link, thereby improving the experience of the non-AP MLD when roaming on the AP MLD 2, achieving basically uninterrupted roaming, and allowing AP MLD 2 to reserve data and configure communications for the non-AP MLD in advance, further reducing roaming latency.

In some embodiments of the present application, the backhaul link is a wireless backhaul link. In some embodiments of the present application, the context migration information includes a first frame and a second frame, the first frame being used to convey information about a non-AP MLD roaming between AP MLD 1 and AP MLD 2, and the second frame confirming the receipt of the first frame, modifying or suggesting information carried by the first frame, and/or carrying information requested by the first frame. In some embodiments of the present application, the context migration information includes a first frame and a response frame, the first frame being an action frame being used to convey information about a non-AP MLD roaming between AP MLD 1 and AP MLD 2, and the response frame being used to respond to the receipt of the first frame. In some embodiments of the present application, the context migration information includes a first frame, the first frame being an action frame being used to convey information about a non-AP MLD roaming between AP MLD 1 and AP MLD 2, and the receiver does not need to confirm receipt of the action frame.

In some embodiments of the present application, the first frame is used to indicate one or more of the following information: channel information, resource scheduling information, power information, maximum number of transmit/receive spatial streams, enhanced distributed channel access EDCA parameter set, emergency preparedness communication service EPCS information, buffer status report BSR information, sequence number SN, data packet number PN, block acknowledgment BA session information, multi-access point AP mode, power information, target wake-up time TWT information, limited target wake-up time service phase R-TWT SP information, service identifier to link TID-to-Link mapping, extended capability information, extremely high throughput EHT capability information, enhanced multi-link EML capability information, MLD capability and operation information, new link ID, and data to be transmitted.

In some embodiments of the present application, the channel information is used to indicate the channel information supported by the non-AP MLD and/or the channel information corresponding to the link established by the non-AP MLD; the resource scheduling information is used to indicate the resource unit RU information used by the non-AP MLD to communicate with the AP MLD 1; the power information is used to indicate the transmit power information used by the non-AP MLD to communicate with the AP MLD 1; the maximum number of transmit/receive spatial streams is used to indicate the maximum number of transmit/receive spatial streams supported by the non-AP MLD; and the EDCA parameter set is used to indicate the number of transmit/receive spatial streams supported by the non-AP MLD. The EDCA parameter set supported by the non-AP MLD or the EDCA parameter set established between the non-AP MLD and the AP MLD 1; the EPCS information is used to indicate the EPCS capability information, EPCS subscription information and EPCS activation status information supported by the non-AP MLD, and/or is used to indicate the EDCA parameter set for the non-AP MLD to request the non-AP MLD to establish an EPCS priority access permission and EPCS priority access with the AP MLD 2; the BSR information is used to indicate the cache status information of the non-AP MLD; the SN is used to indicate the SN of the frame between the non-AP MLD and the AP MLD 1; the PN is used to indicate the PN that has been sent, the PN to be sent, or the PN that has not been sent between the non-AP MLD and the AP MLD 1; the BA session information is used to indicate the block confirmation session information established between the non-AP MLD and the AP MLD 1; the multi-AP mode is used to indicate the multi-AP collaboration mode supported by the non-AP MLD; the power information is used to indicate the non-AP MLD sleep policy information and/or supported sleep mechanisms; the TWT information is used to indicate the TWT information established between the non-AP MLD and the AP MLD 1; the R-TWT SP information is used to indicate the R-TWT SP information established between the non-AP MLD and the AP MLD 1; the TID-to-Link mapping is used to indicate the TID-to-Link mapping scheme established between the non-AP MLD and the AP MLD 1, or to indicate the TID-to-Link mapping scheme of the link established between the non-AP MLD request and the AP MLD 2; the extended capability information is used to indicate the extended capability information of the non-AP MLD; the EHT capability information is used to indicate the EHT capability information of the non-AP MLD; the EML capability information is used to indicate the EML capability information of the non-AP MLD; the MLD capability and operation information is used to indicate the MLD capability and operation information of the non-AP MLD; the new link ID is indicated as the link between the non-AP MLD and the AP MLD 2 to establish a link ID of the connection; the data to be transmitted is used to indicate the unsent data in the downlink buffer of the AP MLD 1 to the non-AP MLD that is about to roam.

In some embodiments of the present application, the backhaul link is a wired backhaul link. In some embodiments of the present application, the context migration information includes one or more of the following information: channel information, resource scheduling information, power information, maximum number of transmit/receive spatial streams, enhanced distributed channel access EDCA parameter set, emergency preparedness communication service EPCS information, buffer status report BSR information, sequence number SN, data packet number PN, block acknowledgement BA session information, multiple access point AP mode, power information, target wake time TWT information, target wake time service phase R-TWT SP information, service identifier to link TID-to-Link mapping, extended capability information, extremely high throughput EHT capability information, enhanced multi-link EML capability information, MLD capability and operation information, new link ID, and pending data to be transmitted. In some embodiments of the present application, the channel information is used to indicate the channel information supported by the non-AP MLD and/or the channel information corresponding to the link established by the non-AP MLD; the resource scheduling information is used to indicate the resource unit RU information used by the non-AP MLD to communicate with the AP MLD 1; the power information is used to indicate the transmission power information used by the non-AP MLD to communicate with the AP MLD 1; the maximum number of transmit/receive spatial streams is used to indicate the maximum number of transmit/receive spatial streams supported by the non-AP MLD; the EDCA parameter set is used to indicate the EDCA parameter set supported by the non-AP MLD or to indicate the number of transmit/receive spatial streams used by the non-AP MLD to communicate with the AP MLD 1. The EPCS information is used to indicate the EPCS capability information, EPCS subscription information and EPCS activation status information supported by the non-AP MLD, and/or to indicate that the non-AP MLD requests to establish an EPCS priority access permission and an EDCA parameter set for EPCS priority access with the AP MLD 2; the BSR information is used to indicate the cache status information of the non-AP MLD; the SN is used to indicate the SN of the frame between the non-AP MLD and the AP MLD 1; the PN is used to indicate the PN that has been sent, the PN that is about to be sent, or the PN that has not been sent between the non-AP MLD and the AP MLD 1; the BA session information is used to indicate the PN of the non-AP MLD. The block confirmation session information established between the MLD and the AP MLD 1; the multi-AP mode is used to indicate the multi-AP cooperation mode supported by the non-AP MLD; the power information is used to indicate the sleep policy information and/or supported sleep mechanism of the non-AP MLD; the TWT information is used to indicate the TWT information established between the non-AP MLD and the AP MLD 1; the R-TWT SP information is used to indicate the R-TWT SP information established between the non-AP MLD and the AP MLD 1; the TID-to-Link mapping is used to indicate the TID-to-Link mapping scheme established between the non-AP MLD and the AP MLD 1, or to indicate the TID-to-Link mapping scheme established between the non-AP MLD and the AP MLD 1, or to indicate the TID-to-Link mapping scheme established between the non-AP MLD and the AP MLD 1. The MLD requests a TID-to-Link mapping scheme for the link established between the non-AP MLD and the AP MLD 2; the extended capability information is used to indicate the extended capability information of the non-AP MLD; the EHT capability information is used to indicate the EHT capability information of the non-AP MLD; the EML capability information is used to indicate the EML capability information of the non-AP MLD; the MLD capability and operation information is used to indicate the MLD capability and operation information of the non-AP MLD; the new link ID indicates the link ID for establishing a connection between the non-AP MLD and the AP MLD 2; the data to be transmitted is used to indicate the unsent data that the AP MLD 1 downlink caches to the non-AP MLD that is about to roam.

Context migration design between the current AP MLD and the target AP MLD:

The various solutions designed in the above embodiments all involve context migration between the current AP MLD and the target AP MLD. It is worth noting that the context migration steps in some of the aforementioned embodiments (in the figures) are not limited to the times listed in the figures, and this is not a limitation in the present embodiment. Furthermore, depending on whether the backhaul link between the current AP MLD and the target AP MLD is a wireless link or a wired link, the present embodiment makes the following design.

Example 5: Wireless backhaul between APs and MLDs:

When wireless backhaul is used for context migration between the current AP MLD and the target AP MLD, a link must be established between the current AP MLD and the target AP MLD first (i.e., Multi-Link Setup is completed). This embodiment uses the link established between the subordinate AP 3 of (current) AP MLD 1 and the subordinate AP 3 of (target) AP MLD 2 as an example for description as the backhaul link, but the present application is not limited thereto. For example, the link established between the subordinate AP x of (current) AP MLD 1 (x is less than or equal to the maximum number of subordinate APs supported by AP MLD 1, in this example, x is equal to 1, 2, 3) and the subordinate AP y of (target) AP MLD 2 (y is less than or equal to the maximum number of subordinate APs supported by AP MLD 2, in this example, y is equal to 1, 2, 3) as the backhaul link.

In addition, frames used for context migration between the current AP MLD and the target AP MLD can be implemented in the following three ways according to their types.

Method 1: Request frame + response frame

FIG5B is a flow chart of a communication method for a context migration method based on multi-link device roaming provided by an embodiment of the present application. As shown in FIG5B , (current) AP MLD 1 sends a request frame 2 to (target) AP MLD 2, requesting that the relevant parameters/information of the non-AP MLD that is about to initiate roaming be passed to (target) AP MLD 2. After receiving the request frame 2, (target) AP MLD 2 returns a response frame 2 to (current) AP MLD 1 after a certain interval (e.g., a short interframe space (SIFS) duration, but the embodiment of the present application is not limited thereto and may also be other durations, such as a priority interframe space (PIFS), etc.). The response frame 2 may include one or more of the following functions:

1) Only confirm the successful reception of the information sent by request frame 2 (that is, accept the information carried by request frame 2 by default).

2) Reject and/or make suggestions for the information sent in Request Frame 2 (i.e., modify the information carried in Request Frame 2 or suggest more appropriate information). Also carry parameters/information of (target) AP MLD 2 (i.e., carry the information requested in Request Frame 2, etc.).

Note: In the above example and Figure 5B, (current) AP MLD 1 sends a request frame 2 to (target) AP MLD 2, and (target) AP MLD 2 responds with a response frame 2. It can also be that (target) AP MLD 2 sends a request frame 2 to (current) AP MLD 1, and (current) AP MLD 1 responds with a response frame 2.

Mode 2: Action frame (with ACK frame):

Figure 5C is a flow chart illustrating a communication method for context migration based on multi-link device roaming, as provided in an embodiment of the present application. As shown in Figure 5C , in Method 2, Request Frame 2 is designed as an Action Frame (indicated by the Frame Control field), which requires an acknowledgment (Ack) response from the recipient. As shown in Figure 5C , (current) AP MLD 1 sends a Request Frame 2 to (target) AP MLD 2, requesting that relevant parameters/information of the non-AP MLD that is about to initiate roaming be transferred to (target) AP MLD 2. After receiving Request Frame 2, (target) AP MLD 2 responds with an acknowledgment frame (Ack frame) to (current) AP MLD 1 after a predetermined interval (e.g., a Short Interframe Space (SIFS) duration, although this embodiment of the present application is not limited thereto and may also be other durations, such as a Priority Interframe Space (PIFS)). The acknowledgment frame (Ack frame) merely confirms the successful receipt of the information sent in Request Frame 2 (i.e., implicitly accepts the information carried in Request Frame 2).

Method 3: Action No Ack frame:

In Mode 3, Request Frame 2 is designed as an Action No Ack (indicated by the Frame Control field). As shown in Figure 5D, (current) AP MLD 1 sends Request Frame 2 to (target) AP MLD 2, requesting that the parameters/information of the non-AP MLD that is about to initiate roaming be transferred to (target) AP MLD 2. The sender assumes that the receiver has successfully received and accepted the information carried in Request Frame 2.

The following is the format design of the request frame 2 and response frame 2 in the above three methods:

Request frame 2 format design:

The request frame 2 for context migration may include some or all of the information carried by the link reconfiguration request frame in some of the above embodiments. For example, the request frame 2 may include one or more of the following information of non-AP MLD: channel and bandwidth, RU allocation, Power limit, Max TX/RX Nss, EDCA parameter set, EPCS information, BSR-related information, SN (Sequence Number), PN (Packet Number), BA session, multi-AP mode, power-related information, TWT element, R-TWT-related information, TID-to-Link mapping, extended capability element, EHT capability element, EML capability field, MLD capabilities and operations, new link ID, and pending data (Pending Data): unsent data buffered downlink by the current AP MLD to the non-AP MLD to which roaming is to begin. A detailed explanation of the above information is provided in a) Link Reconfiguration Request frame format design and will not be repeated here. Note that the pending data is also included here. Note: This is not an exhaustive list; theoretically, it should include all the information carried by the Link Reconfiguration Request frame.

a) Response frame 2 format design:

The response frame 2 for context migration may include part or all of the information carried by the link reconfiguration response frame in some of the above-mentioned embodiments, which will not be repeated here. The response frame 2 may need to convert the information carried by the request frame 2 (see the above-mentioned embodiments for details) to facilitate subsequent data transmission/communication after the non-AP MLD switches to the (target) AP MLD 2.

b) Example of request frame 2 and response frame 2:

In a) and b), the contents that the request frame 2 and response frame 2 can contain are designed and given examples respectively. In practice, the request frame 2 and response frame 2 can be the FT request frame and FT response frame that already exist in the IEEE 802.11 standard. Then, the information/content that the request frame 2 can carry is carried by the frame body of the FT request frame, and the information/content that the response frame 2 can carry is carried by the frame body of the FT response frame. The above-mentioned response can also be replaced by the FT response frame.

It should be noted that this is only a possible example, and the frame format design of this embodiment is not limited to the FT request frame and the FT response frame.

Effects that can be achieved by this embodiment: The information exchange between the current AP MLD and the target AP MLD not only allows the non-AP MLD to seamlessly connect to the target AP MLD while maintaining State 4, but also allows the target AP MLD to reserve data and configure communications for the non-AP MLD in advance, further reducing roaming latency.

Example 6: Using wired backhaul between APs and MLDs:

If a wired backhaul is used for context migration between the current AP MLD and the target AP MLD, the IEEE 802.11 standard does not need to define the frame type and specific format used for the context exchanged between the current AP MLD and the target AP MLD. Instead, the IEEE 802.11 standard only defines the content of the exchange between the current AP MLD and the target AP MLD. Since the content of the exchange between the current AP MLD and the target AP MLD has been designed and explained in detail in some of the aforementioned embodiments, in this embodiment, it is sufficient to specify that the information exchanged between the current AP MLD and the target AP MLD includes the content carried in the request frame 2 and the response frame 2 in some of the aforementioned embodiments.

Effects that can be achieved by this embodiment: The current AP MLD and the target AP MLD exchange information through a wired backhaul link, which not only avoids the delay caused by channel contention (can achieve almost no delay) but also ensures the reliability of transmission.

FIG6 is a flow chart illustrating a method for information conversion based on multi-link device roaming according to an embodiment of the present application. As shown in FIG6 , the method for information conversion based on multi-link device roaming is performed on a non-AP MLD. The method includes at least one of the following operations: Operation 601: When a non-AP MLD roams between a first access point multi-link device AP MLD 1 and a second access point multi-link device AP MLD 2, the non-AP MLD converts information between the non-AP MLD and AP MLD 1 to adapt communication between the non-AP MLD and AP MLD 2.

Through the above technical solution, the AP MLD 1 converts the information between the non-AP MLD and the AP MLD 1 to adapt to the communication between the non-AP MLD and the AP MLD 2, thereby improving the experience of the non-AP MLD when roaming on the AP MLD 2, achieving basically uninterrupted roaming, facilitating the non-AP MLD and the AP MLD 2 to communicate normally as soon as possible, and shortening the roaming delay.

In some embodiments of the present application, the information between the non-AP MLD and the AP MLD 1 includes one or more of the following information: channel information, resource scheduling information, power information, maximum number of transmit/receive spatial streams, enhanced distributed channel access EDCA parameter set, emergency preparedness communication service EPCS information, buffer status report BSR information, sequence number SN, data packet number PN, block confirmation BA session information, multi-access point AP mode, power information, target wake-up time TWT information, target wake-up time service phase R-TWT SP information, service identifier to link TID-to-Link mapping, extended capability information, Extremely high throughput (EHT) capability information, enhanced multi-link (EML) capability information, MLD capability and operation information, and new link ID.

In some embodiments of the present application, the channel information is used to indicate the channel information supported by the non-AP MLD and/or the channel information corresponding to the link established by the non-AP MLD; the resource scheduling information is used to indicate the resource unit RU information used by the non-AP MLD to communicate with the AP MLD 1; the power information is used to indicate the transmit power information used by the non-AP MLD to communicate with the AP MLD 1; the maximum number of transmit/receive spatial streams is used to indicate the maximum number of transmit/receive spatial streams supported by the non-AP MLD; the EDCA parameter set is used to indicate the EDCA parameter set supported by the non-AP MLD or to indicate the EDCA parameter set supported by the non-AP MLD. The EDCA parameter set established between the non-AP MLD and the AP MLD 1; the EPCS information is used to indicate the EPCS capability information, EPCS subscription information and EPCS activation status information supported by the non-AP MLD, and/or is used to indicate that the non-AP MLD requests to establish an EPCS priority access permission and an EDCA parameter set for EPCS priority access with the AP MLD 2; the BSR information is used to indicate the cache status information of the non-AP MLD; the SN is used to indicate the SN of the frame between the non-AP MLD and the AP MLD 1; the PN is used to indicate the PN that has been sent between the non-AP MLD and the AP MLD 1, or the PN that is about to be sent, or Unsent PN; the BA session information is used to indicate the block confirmation session information established between the non-AP MLD and the AP MLD 1; the multi-AP mode is used to indicate the multi-AP collaboration mode supported by the non-AP MLD; the power information is used to indicate the sleep policy information and/or supported sleep mechanism of the non-AP MLD; the TWT information is used to indicate the TWT information established between the non-AP MLD and the AP MLD 1; the R-TWT SP information is used to indicate the R-TWT SP information established between the non-AP MLD and the AP MLD 1; the TID-to-Link mapping is used to indicate the TWT information established between the non-AP MLD and the AP The TID-to-Link mapping scheme established between the non-AP MLD and the AP MLD 1, or the TID-to-Link mapping scheme for indicating the link established between the non-AP MLD request and the AP MLD 2; the extended capability information is used to indicate the extended capability information of the non-AP MLD; the EHT capability information is used to indicate the EHT capability information of the non-AP MLD; the EML capability information is used to indicate the EML capability information of the non-AP MLD; the MLD capability and operation information is used to indicate the MLD capability and operation information of the non-AP MLD; the new link ID indicates the link ID for establishing a connection between the non-AP MLD and the AP MLD 2.

Example 7: Method for converting information indicated by context migration between the current AP MLD and the target AP MLD:

The parameters/configurations/resource allocations used during communication between the non-AP MLD and (current) AP MLD 1 may not be suitable for the communication needs of the non-AP MLD after switching to (target) AP MLD 2. Therefore, when the non-AP MLD roams, the parameters/configurations/resource allocations between the non-AP MLD and (current) AP MLD 1 may need to be converted/updated to meet the communication needs between the non-AP MLD and (target) AP MLD 2. Specifically, one or more of the following parameters/configurations/resource allocations may need to be converted/updated:

Channel and bandwidth: Because the channel configurations of the BSSs where (current) AP MLD 1 and (target) AP MLD 2 are located (for example, the channel number of the main 20 MHz channel, the working bandwidth, etc.) may be inconsistent, after the non-AP MLD switches to the (target) AP MLD 2, the (target) AP MLD 2 needs to reconfigure the working channel for the non-AP MLD based on the channel configuration of its own BSS. For example, it notifies the non-AP MLD to switch its main 20 MHz channel to the main 20 MHz channel of the BSS where the target AP MLD 2 is located; and notifies the non-AP MLD to update the working bandwidth to the bandwidth corresponding to the intersection of "channels supported by the non-AP MLD" and "channels supported by the (target) AP MLD 2".

RU Allocation: Because the channel configurations (e.g., primary 20 MHz channel number, operating bandwidth, etc.) of the BSSs in which (current) AP MLD 1 and (target) AP MLD 2 reside may be inconsistent, the RUs (indexes) allocated to the non-AP MLD operating under (current) AP MLD 1 may become unavailable after switching to (target) AP MLD 2. Therefore, (target) AP MLD 2 needs to reassign RUs (indexes) to the non-AP MLD based on the channel configuration of its own BSS, for example, by updating the RUs (indexes) for the non-AP MLD.

Power Limit: Because the transmit power limits (e.g., maximum and minimum transmit power) of the associated non-AP MLDs supported by (current) AP MLD 1 and (target) AP MLD 2 may differ, the power limit used by the non-AP MLD under (current) AP MLD 1 may not be compatible after switching to (target) AP MLD 2. Therefore, (target) AP MLD 2 needs to reassign the transmit power limit to the non-AP MLD based on the transmit power limit of the associated non-AP MLD that it can accept.

Max TX/RX Nss: Because the maximum number of transmit or receive spatial streams (Nss) supported by (current) AP MLD 1 and (target) AP MLD 2 may differ, the Nss used by the non-AP MLD under (current) AP MLD 1 may not match after switching to (target) AP MLD 2. Therefore, (target) AP MLD 2 needs to set the maximum TX/RX Nss that the non-AP MLD can use based on its own Max TX/TX Nss.

EDCA parameter set: The EDCA parameter set configuration (such as access category (AC), maximum contention window (CWmax), maximum contention window (CWmin), backoff counter (BCC), arbitrary interframe number (AIFSN), and maximum transmission opportunity time (TXOP limit)) when the non-AP MLD communicates with the (current) AP MLD 1 may not be applicable to the non-AP MLD communicating with the (target) AP MLD 2. Because of the communication issues, the EDCA parameter set assigned to the non-AP MLD operating under (current) AP MLD 1 may need to be updated after switching to (target) AP MLD 2. Therefore, (target) AP MLD 2 needs to reassign the EDCA parameter set to the non-AP MLD based on its own operating status. For example, it needs to set new parameters such as the access category (AC), maximum contention window (CWmax), maximum contention window (CWmin), backoff counter, arbitrary interframe number (AIFSN), and maximum transmission opportunity time (TXOP limit).

EPCS Information: EPCS information includes the subscription status and activation status of the EPCS priority access service, as well as the EDCA parameter set for EPCS priority access. When a non-AP MLD communicates with (current) AP MLD 1, the EPCS information configuration (e.g., subscription status, activation status, EDCA parameter set for EPCS priority access) is transferred to (target) AP MLD 2 when the non-AP MLD switches to (target) AP MLD 2. The EPCS subscription status and activation status are transferred to (target) AP MLD 2 (no conversion or update is required). However, the EDCA parameter set for EPCS priority access may need to be updated by (target) AP MLD 2 based on its operating status.

BSR-related information: The specific format and content of the BSR are described in the BSR Control subfield and/or QoS Control subfield of the IEEE 802.11 standard. For example, this information includes the type of cached service and the corresponding cache size. The BSR-related information that a Non-AP MLD communicates with (current) AP MLD 1 can be transferred to (target) AP MLD 2 using two different transfer strategies:

1) Migrate all BSR information to (target) AP MLD 2 without any modification.

2) The information corresponding to the higher-priority services contained in the BSR is migrated to (target) AP MLD 2. The information corresponding to the lower-priority services contained in the BSR is directly discarded and not migrated to (target) AP MLD 2. After the non-AP MLD switches to (target) AP MLD 2, the BSR information is cached again and exchanged.

-SN (Sequence Number): SN is the sequence number of the frame sent by the sender. The SN of the Non-AP MLD communicating with (current) AP MLD 1 can have two migration strategies when switching to (target) AP MLD 2:

1) The SN corresponding to the frame exchange between the non-AP MLD and (current) AP MLD 1 at the moment of AP MLD handover is migrated to (target) AP MLD 2 without modification. After the handover is completed, when (target) AP MLD 2 communicates with the non-AP MLD, (target) AP MLD 2 and the non-AP MLD continue to use the previous SN to transmit subsequent frames;

2) The SN corresponding to the frame exchange between the non-AP MLD and (current) AP MLD 1 at the moment of AP MLD handover is discarded and not transferred to (target) AP MLD 2. After the handover is completed, when (target) AP MLD 2 communicates with the non-AP MLD, (target) AP MLD 2 and the non-AP MLD reuse the new SN to transmit subsequent frames.

-PN (Packet Number): PN is used to number MSDUs, A-MSDUs, and MPDUs. The PN corresponding to the packet when the Non-AP MLD communicates with (current) AP MLD 1 can have two migration strategies when switching to (target) AP MLD 2:

1) The PN corresponding to the frame exchange between the non-AP MLD and (current) AP MLD 1 at the time of AP MLD handover is migrated to (target) AP MLD 2 without modification. After the handover is completed, when (target) AP MLD 2 communicates with the non-AP MLD, (target) AP MLD 2 and the non-AP MLD continue to transmit subsequent frames using the previous PN;

2) The PN corresponding to the frame exchange between the non-AP MLD and (current) AP MLD 1 at the moment of AP MLD handover is discarded and not transferred to (target) AP MLD 2. After the handover is completed, when (target) AP MLD 2 communicates with the non-AP MLD, (target) AP MLD 2 and the non-AP MLD reacquire data and use the new PN to transmit subsequent frames.

BA-related information: Used to indicate the BlockAck session information established by the sender and receiver, such as the BA agreement and BA scoreboarding. For details, see the IEEE 802.11 standard. When the BlockAck session information when the Non-AP MLD communicates with (current) AP MLD 1 is switched to (target) AP MLD 2, the BA agreement and BA scoreboard can have two migration strategies:

1) The BA agreement and BA scoreboard between the non-AP MLD and (current) AP MLD 1 at the time of AP MLD handover are migrated to (target) AP MLD 2 without modification. After the handover, when (target) AP MLD 2 communicates with the non-AP MLD, there is no need to re-establish the BA agreement between them, and subsequent communications continue using the previous BA scoreboard.

2) The BA agreement between the non-AP MLD and (current) AP MLD 1 is terminated at the moment of AP MLD handover, and the BA is not transferred to (target) AP MLD 2. After the handover is completed, when (target) AP MLD 2 communicates with the non-AP MLD, (target) AP MLD 2 and the non-AP MLD re-establish the BA agreement and perform a new BA scoreboard operation.

-Multi-AP Mode: Since the multi-AP collaboration modes supported by (current) AP MLD 1 and (target) AP MLD 2 (e.g., C-TDMA, C-OFDMA, C-SR, C-BF, J-TX, etc.) may be inconsistent, the multi-AP collaboration mode supported by the non-AP MLD under (current) AP MLD 1 may not be available after switching to (target) AP MLD 2. Therefore, (target) AP MLD 2 needs to take the intersection of its own supported multi-AP collaboration modes and the multi-AP collaboration modes supported by the non-AP MLD and then re-instruct the non-AP MLD on the multi-AP collaboration mode.

-Power-related information: Power-related information (or sleep policy information) when the Non-AP MLD communicates with (current) AP MLD 1 The sleep policy established by the non-AP MLD when operating under (current) AP MLD 1 may not be applicable to communication with (target) AP MLD 2. Therefore, the sleep policy established by the non-AP MLD when operating under (current) AP MLD 1 may need to be updated after switching to (target) AP MLD 2. Therefore, (target) AP MLD 2 needs to reassign the sleep policy to the non-AP MLD based on its own operating status.

-TWT element: The TWT SP established by the non-AP MLD when communicating with (current) AP MLD 1 may not be applicable to the non-AP MLD's communication with (target) AP MLD 2. Therefore, the TWT SP established by the non-AP MLD when operating under (current) AP MLD 1 may need to be updated after switching to (target) AP MLD 2. Therefore, (target) AP MLD 2 needs to re-establish the TWT SP for the non-AP MLD based on its own operating status.

-R-TWT element: The TWT SP established by the non-AP MLD when communicating with (current) AP MLD 1 may not be applicable to the communication between the non-AP MLD and (target) AP MLD 2. Therefore, the TWT SP established by the non-AP MLD when operating under (current) AP MLD 1 may need to be updated after switching to (target) AP MLD 2. Therefore, (target) AP MLD 2 needs to re-establish the TWT SP for the non-AP MLD based on its own operating status.

-TID-to-Link Mapping: The TID-to-Link mapping used by the non-AP MLD when communicating with (current) AP MLD 1 may not be applicable to the communication between the non-AP MLD and (target) AP MLD 2, for example, if a link on (target) AP MLD 2 is unavailable or overloaded and cannot carry more TIDs. Therefore, the TID-to-Link mapping used by the non-AP MLD when operating under (current) AP MLD 1 may need to be updated after switching to (target) AP MLD 2. Therefore, (target) AP MLD 2 needs to re-map the TID-to-Link mapping for the non-AP MLD based on its own operating status, for example, remapping some TIDs to the new Link ID while retaining other TIDs mapped to the old Link ID.

- Extended Capability Elements: Because the extended capabilities supported by (current) AP MLD 1 and (target) AP MLD 2 may differ, some capabilities in the extended capability elements used by the non-AP MLD when operating under (current) AP MLD 1 may not be compatible after switching to (target) AP MLD 2. Therefore, (target) AP MLD 2 needs to configure the extended capabilities that the non-AP MLD can use based on its own extended capability information.

-EHT Capability Element: Because the Extreme Throughput (EHT) capabilities supported by (current) AP MLD 1 and (target) AP MLD 2 may differ, some Extreme Throughput (EHT) capabilities used by non-AP MLD under (current) AP MLD 1 may not be compatible after switching to (target) AP MLD 2. Therefore, (target) AP MLD 2 needs to configure the Extreme Throughput (EHT) capabilities that non-AP MLD can use based on its own extended capability information.

-New Link ID: The Link ID established when the non-AP MLD communicates with (current) AP MLD 1 may not be suitable for communication between the non-AP MLD and (target) AP MLD 2. Therefore, the Link ID used by the non-AP MLD under (current) AP MLD 1 may need to be updated after switching to (target) AP MLD 2. Therefore, (target) AP MLD 2 needs to reassign a Link ID to the non-AP MLD based on its existing Link ID. For example, it can use the Link ID currently unassigned by (target) AP MLD 2 for the new link established between the non-AP MLD and (target) AP MLD 2 after the handover.

The effect that can be achieved by this embodiment is as follows: When the Non-AP MLD switches to the target AP MLD, the current AP MLD and the target AP MLD update/reconfigure some contexts, which can facilitate normal communication between the non-AP MLD and the target AP MLD as soon as possible and shorten the roaming delay.

Roaming completion determination method and subsequent operation design:

FIG7A is a flow chart illustrating a multi-link device roaming communication method according to an embodiment of the present application. As shown in FIG7A , the multi-link device roaming communication method is performed by a non-AP MLD. The communication method includes at least one of the following operations: Operation 701A: After the non-AP MLD roams from a first access point multi-link device (AP MLD) 1 to a second access point multi-link device (AP MLD) 2, the non-AP MLD confirms the roaming result.

Through the above technical solution, the non-AP MLD confirms the roaming result, thereby improving the experience of the non-AP MLD when roaming the AP MLD 2 and achieving basically uninterrupted roaming. The confirmation operation performed by the non-AP MLD after the roaming is completed can ensure that the newly established link of the non-AP MLD after roaming the AP MLD 2 works normally.

In some embodiments of the present application, the non-AP MLD confirming the roaming result includes: the non-AP MLD sending a roaming confirmation message to AP MLD 2 and receiving a roaming response message from AP MLD 2. In some embodiments of the present application, after the non-AP MLD receives the roaming response message from AP MLD 2, the non-AP MLD sends a roaming completion message to AP MLD 1. In some embodiments of the present application, the roaming completion message includes a roaming MLD address field for indicating the MLD MAC address of the non-AP MLD that completed the roaming. In some embodiments of the present application, the roaming confirmation information and the roaming response information include one of the following combinations: a request to send RTS frame and a clear to send CTS frame, a probe request frame and a probe response frame, a multi-link probe request frame and a multi-link probe response frame, a buffer status report polling BSRP trigger frame and a triggered physical layer protocol data unit TB PPDU with a buffer status report BSR, a multi-user request to send frame MU-RTS trigger frame and a CTS frame, or a data frame and a response frame.

In some embodiments of the present application, the frame body of the roaming confirmation information carries the converted non-AP MLD and the The information between the non-AP MLD and the AP MLD 1 after the conversion is adapted to communication between the non-AP MLD and the AP MLD 2. In some embodiments of the present application, the information between the non-AP MLD and the AP MLD 1 after the conversion includes one or more of the following information: channel information, resource scheduling information, power information, maximum number of transmit/receive spatial streams, enhanced distributed channel access (EDCA) parameter set, emergency preparedness communication service (EPCS) information, buffer status report (BSR) information, sequence number (SN), packet number (PN), block acknowledgement (BA) session information, multi-access point (AP) mode, power information, target wake time (TWT) information, restricted target wake time service phase (R-TWT) information, service identifier to link (TID-to-Link) mapping, extended capability information, extremely high throughput (EHT) capability information, enhanced multi-link (EML) capability information, MLD capability and operation information, and a new link ID. In some embodiments of the present application, the channel information is used to indicate channel information supported by the non-AP MLD and/or channel information corresponding to the link established by the non-AP MLD; the resource scheduling information is used to indicate resource unit RU information used by the non-AP MLD to communicate with the AP MLD 1; the power information is used to indicate transmit power information used by the non-AP MLD to communicate with the AP MLD 1; the maximum number of transmit/receive spatial streams is used to indicate the maximum number of transmit/receive spatial streams supported by the non-AP MLD; the EDCA parameter set is used to indicate the EDCA parameter set supported by the non-AP MLD or to indicate the EDCA parameter set established between the non-AP MLD and the AP MLD 1; the EPCS information is used to indicate EPCS capability information, EPCS subscription information, and EPCS activation status information supported by the non-AP MLD, and/or to indicate the EDCA parameter set for the non-AP MLD to request to establish EPCS priority access permission and EPCS priority access with the AP MLD 2; and the BSR information is used to indicate the non-AP MLD cache status information; the SN is used to indicate the SN of the frame between the non-AP MLD and the AP MLD 1; the PN is used to indicate the PN that has been sent between the non-AP MLD and the AP MLD 1, or the PN that is about to be sent, or the PN that has not been sent; the BA session information is used to indicate the block confirmation session information established by the non-AP MLD and the AP MLD 1; the multi-AP mode is used to indicate the multi-AP cooperation mode supported by the non-AP MLD; the power information is used to indicate the sleep policy information and/or the supported sleep mechanism of the non-AP MLD; the TWT information is used to indicate the TWT information established between the non-AP MLD and the AP MLD 1; the R-TWT SP information is used to indicate the R-TWT SP information established between the non-AP MLD and the AP MLD 1; the TID-to-Link mapping is used to indicate the TID-to-Link mapping scheme established between the non-AP MLD and the AP MLD 1, or for indicating the non-AP MLD request and the AP MLD 2; the extended capability information is used to indicate the extended capability information of the non-AP MLD; the EHT capability information is used to indicate the EHT capability information of the non-AP MLD; the EML capability information is used to indicate the EML capability information of the non-AP MLD; the MLD capability and operation information is used to indicate the MLD capability and operation information of the non-AP MLD; and the new link ID indicates the link ID of the connection established between the non-AP MLD and the AP MLD 2.

In some embodiments of the present application, the communication method also includes the non-AP MLD performing one or more of the following operations according to the roaming confirmation information: switching the working main channel and working bandwidth to the main channel number and working bandwidth indicated by the AP MLD 2; adjusting the clock information to the clock information of the AP MLD 2; preparing channel access parameters according to the EDCA parameter set indicated by the AP MLD 2; setting the EPCS priority access to an on/off state according to the EPCS information indicated by the AP MLD 2, and if it is in the on state, it is also necessary to perform competitive transmission of EPCS services according to the EDCA parameter set of the EPCS priority access indicated by the AP MLD 2; marking the SN of the next frame communicated with the AP MLD 2 according to the SN indicated by the AP MLD 2; marking the PN of the next media access control protocol data unit MPDU communicated with the AP MLD 2 according to the PN indicated by the AP MLD 2; and The BA scoreboard of the next data transmission communicated with the AP MLD 2 is updated according to the BA session information indicated by the AP MLD 2; the channel resource preemption is prepared according to the multi-AP mode indicated by the AP MLD 2, thereby initiating a corresponding multi-AP collaboration request; the sleep window, sleep interval and clock information are adjusted according to the power information indicated by the AP MLD 2; the TWT SP information is adjusted according to the TWT information and clock information indicated by the AP MLD 2; the R-TWT SP information is adjusted according to the R-TWT information and clock information indicated by the AP MLD 2, and the silent/sleeping state is maintained before the start of the responding R-TWT SP information; the related services of the own are remapped to the new link according to the TID-to-Link mapping indicated by the AP MLD 2 for preparation for sending; the extended capability is enabled/disabled according to the extended capability information indicated by the AP MLD 2; and the EHT capability is enabled/disabled according to the EHT capability information indicated by the AP MLD 2.

Example 8: Method for non-AP MLD to confirm roaming:

After the non-AP MLD completes the switchover (roaming) from the current AP MLD to the target AP MLD, the non-AP MLD can confirm the switchover result. As shown in Figure 7B, the non-AP MLD sends an initial control frame (a control frame type) or roaming confirmation frame (Confirm frame) on the newly established link (e.g., link 2') with (target) AP MLD 2 to test the connectivity of the newly established link. If (target) AP MLD 2 receives the roaming confirmation frame sent by the non-AP MLD, it responds with a roaming acknowledgment frame (Ack frame) on the link where the frame was received, indicating that the established link is normal and roaming is complete.

In addition, you can perform the following two operations to ensure that the non-AP MLD is disconnected from the (current) AP MLD 1:

Option 1: After receiving the roaming acknowledgment frame (Ack frame) from (target) AP MLD 2, the non-AP MLD sends a roaming completion frame to (current) AP MLD 1 on link 1.

Option 2: After (target) AP MLD 2 responds with a roaming acknowledgment frame (Ack frame) to the non-AP MLD, it sends a roaming completion frame to (current) AP MLD 1 via the backhaul link.

Through any of the above two options, after receiving the roaming completion frame, the (current) AP MLD 1 can immediately disconnect (delete link) from the non-AP MLD that is switched to the (target) AP MLD 2, and delete the context information related to the non-AP MLD (see the design of the previous embodiment for specific information).

The effects that can be achieved by this embodiment are: the confirmation operation performed by the non-AP MLD after roaming is completed can ensure that the newly established link of the non-AP MLD works normally after switching to (target) AP MLD 2, and can also ensure that the non-AP MLD disconnects from the (current) AP MLD 1 after switching to (target) AP MLD 2. In addition, it is also used to announce that the next (target) AP MLD 2 will continue to serve the non-AP MLD.

FIG8A is a flow chart illustrating a multi-link device roaming communication method according to an embodiment of the present application. As shown in FIG8A , the multi-link device roaming communication method is executed by an access point multi-link device (AP MLD), wherein the communication method includes at least one of the following operations: Operation 801A: After a non-AP MLD roams from a first access point multi-link device (AP MLD) 1 to a second access point multi-link device (AP MLD) 2, AP MLD 2 confirms the roaming result.

Through the above technical solution, the AP MLD 2 confirms the roaming result, thereby improving the experience of the non-AP MLD when roaming on the AP MLD 2 and achieving basically uninterrupted roaming. The confirmation operation performed by the AP MLD 2 after the roaming is completed can ensure that the newly established link of the non-AP MLD after roaming on the AP MLD 2 works normally.

In some embodiments of the present application, AP MLD 2 confirming the roaming result includes: AP MLD 2 sending a roaming confirmation message to the non-AP MLD and receiving a roaming response message from the non-AP MLD. In some embodiments of the present application, after AP MLD 2 receives the roaming response message from the non-AP MLD, AP MLD 2 sends a roaming completion message to AP MLD 1. In some embodiments of the present application, the roaming completion message includes a roaming MLD address field for indicating the MLD MAC address of the non-AP MLD that completed the roaming.

In some embodiments of the present application, the roaming confirmation message and the roaming response message include one of the following combinations: a request-to-send (RTS) frame and a clear-to-send (CTS) frame, a probe request frame and a probe response frame, a multilink probe request frame and a multilink probe response frame, a buffer status report poll (BSRP) trigger frame and a trigger-based physical layer protocol data unit (TB) PPDU with a buffer status report (BSR), a multi-user request-to-send (MU-RTS) trigger frame and a CTS frame, or a data frame and a response frame. In some embodiments of the present application, the frame body of the roaming confirmation message carries converted information between the non-AP MLD and the AP MLD 1 to adapt the communication between the non-AP MLD and the AP MLD 2.

In some embodiments of the present application, the information between the converted non-AP MLD and the AP MLD 1 includes one or more of the following information: channel information, resource scheduling information, power information, maximum number of transmit/receive spatial streams, enhanced distributed channel access EDCA parameter set, emergency preparedness communication service EPCS information, buffer status report BSR information, sequence number SN, data packet number PN, block acknowledgment BA session information, multi-access point AP mode, power information, target wake-up time TWT information, limited target wake-up time service phase R-TWT SP information, service identifier to link TID-to-Link mapping, extended capability information, extremely high throughput EHT capability information, enhanced multi-link EML capability information, MLD capability and operation information, and new link ID.

In some embodiments of the present application, the channel information is used to indicate channel information supported by the non-AP MLD and/or channel information corresponding to the link established by the non-AP MLD; the resource scheduling information is used to indicate resource unit RU information used by the non-AP MLD to communicate with the AP MLD 1; the power information is used to indicate transmit power information used by the non-AP MLD to communicate with the AP MLD 1; the maximum number of transmit/receive spatial streams is used to indicate the maximum number of transmit/receive spatial streams supported by the non-AP MLD; the EDCA parameter set is used to indicate the EDCA parameter set supported by the non-AP MLD or to indicate the EDCA parameter set established between the non-AP MLD and the AP MLD 1; the EPCS information is used to indicate EPCS capability information, EPCS subscription information, and EPCS activation status information supported by the non-AP MLD, and/or to indicate the EDCA parameter set for the non-AP MLD to request to establish EPCS priority access permission and EPCS priority access with the AP MLD 2; and the BSR information is used to indicate the non-AP MLD cache status information; the SN is used to indicate the SN of the frame between the non-AP MLD and the AP MLD 1; the PN is used to indicate the PN that has been sent, the PN that is about to be sent, or the PN that has not been sent between the non-AP MLD and the AP MLD 1; the BA session information is used to indicate The block confirmation session information established by the non-AP MLD and the AP MLD 1; the multi-AP mode is used to indicate the multi-AP cooperation mode supported by the non-AP MLD; the power information is used to indicate the sleep policy information and/or the supported sleep mechanism of the non-AP MLD; the TWT information is used to indicate the TWT information established between the non-AP MLD and the AP MLD 1; the R-TWT SP information is used to indicate the R-TWT SP information established between the non-AP MLD and the AP MLD 1; the TID-to-Link mapping is used to indicate the TID-to-Link mapping scheme established between the non-AP MLD and the AP MLD 1, or for indicating the TID-to-Link mapping scheme of the link established between the non-AP MLD request and the AP MLD 2; the extended capability information is used to indicate the extended capability information of the non-AP MLD; the EHT capability information is used to indicate the EHT capability information of the non-AP MLD; the EML capability information is used to indicate the non-AP MLD EML capability information; the MLD capability and operation information is used to indicate the MLD capability and operation information of the non-AP MLD; the new link ID indicates the link ID for establishing a connection between the non-AP MLD and the AP MLD 2.

In some embodiments of the present application, the communication method also includes the AP MLD 2 scheduling the non-AP MLD transmission in combination with the working status of the non-AP MLD.

Example 9: Method for target AP MLD to confirm roaming:

After the non-AP MLD completes the switchover (roaming) from the current AP MLD to the target AP MLD, (target) AP MLD 2 can also confirm the switchover result. As shown in Figure 8B, (target) AP MLD 2 sends an initial control frame (a roaming confirmation frame) on the newly established link (e.g., link 2') with the non-AP MLD to test the connectivity of the newly established link. If the non-AP MLD receives the roaming confirmation frame sent by (target) AP MLD 2, it responds with a roaming acknowledgment frame (Ack frame) on the link where the frame was received, indicating that the established link is normal and roaming is complete.

In addition, the following two operations can be used to disconnect the non-AP MLD from the (current) AP MLD 1:

Option 1: After the non-AP MLD responds with a Roaming Ack frame to (target) AP MLD 2, it sends a Roaming Completion frame to (current) AP MLD 1 on Link 1.

Option 2: After receiving the roaming response frame from the non-AP MLD, (target) AP MLD 2 sends a roaming completion frame to (current) AP MLD 1 via the backhaul link.

Through any of the above two options, after receiving the roaming completion frame, the (current) AP MLD 1 can immediately disconnect (delete link) from the non-AP MLD that is switched to the (target) AP MLD 2, and delete the context information related to the non-AP MLD (see the design of the previous embodiment for specific information).

The effects that can be achieved by this embodiment are: (target) AP MLD 2 performs the confirmation operation after roaming is completed. In addition to ensuring that the newly established link of the non-AP MLD after switching to the (target) AP MLD 2 works normally, and ensuring that the non-AP MLD disconnects from the (current) AP MLD 1 after switching to the (target) AP MLD 2, and announcing that the (target) AP MLD 2 will continue to serve the non-AP MLD, (target) AP MLD 2 can also carry the updated content after the context migration to the non-AP MLD through a new roaming confirmation frame (see Example 10), which to a certain extent ensures that the (target) AP MLD 2 can quickly provide subsequent services to the non-AP MLD, further reducing data interruption/delay during the roaming process of the non-AP MLD.

Example 10: Format design of roaming confirmation frame, roaming response frame and roaming completion frame:

In some embodiments of the present application, the roaming confirmation frame and roaming response frame exchanged between the non-AP MLD and the (target) AP MLD 2 can be any of the following combinations: the roaming confirmation frame is equal to the RTS frame; the roaming response frame is equal to the CTS frame. The roaming confirmation frame is equal to the probe request frame; the roaming response frame is equal to the probe response frame. The roaming confirmation frame is equal to the multilink probe request frame; the roaming response frame is equal to the multilink probe response frame. The roaming confirmation frame is equal to the BSRP trigger frame; the roaming response frame is equal to the TB PPDU with BSR. The roaming confirmation frame is equal to the MU-RTS trigger frame; the roaming response frame is equal to the CTS frame. The roaming confirmation frame is equal to the data frame; the roaming response frame is equal to the response frame.

FIG9A illustrates the format of a roaming confirmation frame provided by an embodiment of the present application. In addition to the exemplary frames described above, a new roaming confirmation frame may be defined, sent by (target) AP MLD 2. As shown in FIG9A , the frame body carries all or part of the information after context conversion/update in some embodiments of the present application. Correspondingly, the non-AP MLD may respond with an acknowledgment frame (Ack frame).

FIG9B is a schematic diagram of the format of a roaming completion frame provided in an embodiment of the present application. A possible roaming completion frame format is shown in FIG9B , wherein the roaming MLD address field is used to indicate the MLD MAC address of the non-AP MLD that completed the roaming. After receiving the frame, the (current) AP MLD 1 disconnects from the non-AP indicated by the roaming MLD address according to the indication of the MLD MAC address. The MLD connection (delete link) deletes the context information related to the non-AP MLD (for details, see the design of the previous embodiment).

This embodiment achieves the following effects: The frames used by the non-AP MLD to confirm roaming completion are designed to ensure the integrity of the confirmation operation. Furthermore, this operation can be performed using existing frames, reducing design and signaling complexity, or using newly designed frames, allowing (target) AP MLD 2 to prepare resources for the non-AP MLD's subsequent transmission, thereby reducing roaming latency.

Example 11: Design of subsequent actions after roaming is completed:

Post-roaming behavior refers to the operations (behaviors) that the non-AP MLD and (target) AP MLD 2 need to perform respectively after the non-AP MLD and (target) AP MLD 2 exchange roaming confirmation frames and roaming response frames as designed by this implementation.

Behavioral design of Non-AP MLD:

The Non-AP MLD needs to perform one or more of the following operations based on the relevant information indicated in the Link Reconfiguration Response frame and/or Roaming Confirm frame sent by the (target) AP MLD 2:

-Switch the working main channel and working bandwidth to the main channel number and working bandwidth indicated by (target) AP MLD 2.

-Adjust its own clock information (TSF, etc.) to the clock information of (target) AP MLD 2 to keep the clock synchronized and facilitate subsequent scheduling.

- Prepare channel access parameters (such as access category (AC), (maximum contention window CWmax), (maximum contention window CWmin), backoff counter (Backoff Counter), arbitrary frame interval number (AIFSN) and maximum transmission opportunity time length (TXOP limit)) according to the EDCA parameter set indicated by the (target) AP MLD 2.

- Set EPCS priority access to on/off according to the EPCS information indicated by (target) AP MLD 2. If it is on, it is also necessary to perform contention transmission of EPCS services according to the EDCA parameter set for EPCS priority access indicated by (target) AP MLD 2.

-Mark the sequence number (Sequence Number) of the next frame communicated with (target) AP MLD 2 according to the SN indicated by (target) AP MLD 2.

-Mark the packet number (Packet Number) of the next MPDU communicated with (target) AP MLD 2 according to the PN indicated by (target) AP MLD 2.

-Update the BA scoreboard for the next data transmission communicated with (target) AP MLD 2 according to the BA related information indicated by (target) AP MLD 2.

-Prepare for channel resource preemption according to the multi-AP mode indicated by (target) AP MLD 2, thereby initiating the corresponding multi-AP collaboration request.

-Adjust its own sleep window, sleep interval and clock information (TSF) according to the power-related information indicated by (target) AP MLD 2.

-Adjust the TWT SP according to the TWT elements and clock information (TSF) indicated by the (target) AP MLD 2.

-Adjust the R-TWT SP according to the R-TWT and clock information (TSF) indicated by the (target) AP MLD 2, and remain silent/sleep before the responding R-TWT SP starts.

-Remap its own related services to the new link and prepare for sending according to the TID-to-Link mapping information indicated by (target) AP MLD 2.

- Enable/disable some of its own extended capabilities according to the extended capability elements indicated by (target) AP MLD 2.

- Enable/disable certain of its own extreme high throughput capabilities according to the EHT capability element indicated by the (target) AP MLD 2.

(Target) Behavioral design of AP MLD 2:

(Target) AP MLD 2 needs to reschedule non-AP MLD transmission based on the working status of the newly switched non-AP MLD and other non-AP MLDs currently in service (such as BSR information, channel status information).

Note: Other actions are completed after the context transfer is completed and/or the roaming confirmation frame is sent (received).

The effect that can be achieved by this embodiment is as follows: The behavior after roaming is completed is designed so that both (target) AP MLD 2 and non-AP MLD are ready for the next transmission, thereby reducing the roaming delay to a certain extent.

Figure 10 is a schematic diagram of a wireless communication device 500 provided in an embodiment of the present application. The wireless communication device can be a relay communication device, an AP, or a STA. The wireless communication device 500 shown in Figure 10 includes a processor 510, which can call and execute a computer program from a memory to implement the method in the embodiment of the present application. In some embodiments of the present application, an AP includes an AP STA or an AP MLD, and a STA includes an AP STA or a non-AP STA or an AP MLD or a non-AP MLD.

Optionally, as shown in FIG10 , the wireless communication device 500 may further include a memory 520. The processor 510 may The computer program is called and executed in the memory 520 to implement the method in the embodiment of the present application. The memory 520 can be a separate device independent of the processor 510 or integrated into the processor 510.

Optionally, as shown in FIG10 , the wireless communication device 500 may further include a transceiver 530. The processor 510 may control the transceiver 530 to communicate with other devices. Specifically, the transceiver 530 may send information or data to other devices or receive information or data sent by other devices. The transceiver 530 may include a transmitter and a receiver. The transceiver 530 may further include one or more antennas.

Optionally, the wireless communication device 500 may specifically be a relay communication device in an embodiment of the present application, and the wireless communication device 500 may implement the corresponding processes implemented by the relay communication device in each method in the embodiment of the present application. For the sake of brevity, they will not be repeated here.

Optionally, the wireless communication device 500 may specifically be a mobile AP in an embodiment of the present application, and the wireless communication device 500 may implement the corresponding processes implemented by the AP in each method in the embodiment of the present application, which will not be described in detail here for the sake of brevity.

Optionally, the wireless communication device 700 may be a STA in the embodiments of the present application, and the wireless communication device 700 may implement the corresponding processes implemented by the STA in the various methods of the embodiments of the present application. For the sake of brevity, these processes are not further described here. In some embodiments of the present application, the STA includes an AP STA or a non-AP STA or an AP MLD or a non-AP MLD.

Figure 11 is a schematic structural diagram of a chip according to an embodiment of the present application. The chip 600 shown in Figure 11 includes a processor 610, which can call and run a computer program from a memory to implement the method according to the embodiment of the present application.

Optionally, as shown in FIG11 , the chip 600 may further include a memory 620. The processor 610 may call and execute a computer program from the memory 620 to implement the method in the embodiment of the present application. The memory 620 may be a separate device independent of the processor 610 or may be integrated into the processor 610.

Optionally, the chip 600 may further include an input interface 630. The processor 610 may control the input interface 630 to communicate with other devices or chips, and specifically, may obtain information or data sent by other devices or chips.

Optionally, the chip 600 may further include an output interface 640. The processor 610 may control the output interface 640 to communicate with other devices or chips, and specifically, may output information or data to other devices or chips.

Optionally, the chip can be applied to the relay communication device in the embodiments of the present application, and the chip can implement the corresponding processes implemented by the relay communication device in each method of the embodiments of the present application. For the sake of brevity, they will not be repeated here.

Optionally, the chip can be applied to the AP in the embodiments of the present application, and the chip can implement the corresponding processes implemented by the AP in each method in the embodiments of the present application. For the sake of brevity, they are not described here.

Optionally, the chip can be applied to the STA in the embodiments of the present application, and the chip can implement the corresponding processes implemented by the STA in the various methods of the embodiments of the present application. For the sake of brevity, they are not described here.

FIG12 is a schematic block diagram of a wireless communication system 700 provided in an embodiment of the present application. As shown in FIG12 , the communication system 700 includes an AP 710, a relay communication device 720, and a STA 730. The AP 710 can be used to implement the corresponding functions implemented by the AP in the above-described method, the relay communication device 720 can be used to implement the corresponding functions implemented by the relay communication device in the above-described method, and the STA 730 can be used to implement the corresponding functions implemented by the STA in the above-described method. For the sake of brevity, these functions are not further described here.

It should be understood that the processor of the embodiment of the present application may be an integrated circuit chip with signal processing capabilities. During implementation, each step of the above method embodiment may be completed by hardware integrated logic circuits in the processor or software instructions.

It is understood that the memory in the embodiments of the present application may be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. It should be noted that the memory of the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory. The embodiments of the present application also provide a computer-readable storage medium for storing a computer program.

Optionally, the computer-readable storage medium may be applied to the relay communication device in the embodiments of the present application, and the computer program causes the computer to execute the corresponding processes implemented by the relay communication device in the various methods of the embodiments of the present application. For the sake of brevity, these processes are not described in detail here. Optionally, the computer-readable storage medium may be applied to the AP in the embodiments of the present application, and the computer program causes the computer to execute the corresponding processes implemented by the AP in the various methods of the embodiments of the present application. For the sake of brevity, these processes are not described in detail here. Optionally, the computer-readable storage medium may be applied to the STA in the embodiments of the present application, and the computer program causes the computer to execute the corresponding processes implemented by the STA in the various methods of the embodiments of the present application. For the sake of brevity, these processes are not described in detail here.

An embodiment of the present application also provides a computer program product, including computer program instructions.

Optionally, the computer program product may be applied to the relay communication device in the embodiments of the present application, and the computer program instructions cause a computer to execute the corresponding processes implemented by the relay communication device in the various methods of the embodiments of the present application. For the sake of brevity, these instructions are not described in detail here. Optionally, the computer program product may be applied to the AP in the embodiments of the present application, and the computer program instructions cause a computer to execute the corresponding processes implemented by the AP in the various methods of the embodiments of the present application. For the sake of brevity, these instructions are not described in detail here. Optionally, the computer program product may be applied to the STA in the embodiments of the present application, and the computer program instructions cause a computer to execute the corresponding processes implemented by the STA in the various methods of the embodiments of the present application. For the sake of brevity, these instructions are not described in detail here.

The embodiment of the present application also provides a computer program.

Optionally, the computer program may be applied to the relay communication device in the embodiment of the present application. When the computer program is run on a computer, the computer executes the corresponding processes implemented by the relay communication device in the various methods of the embodiment of the present application. For the sake of brevity, no further details are given here. Optionally, the computer program may be applied to the AP in the embodiment of the present application. When the computer program is run on a computer, the computer executes the corresponding processes implemented by the AP in the various methods of the embodiment of the present application. For the sake of brevity, no further details are given here. Optionally, the computer program may be applied to the STA in the embodiment of the present application. When the computer program is run on a computer, the computer executes the corresponding processes implemented by the STA in the various methods of the embodiment of the present application. For the sake of brevity, no further details are given here.

Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims (123)

A communication method based on multi-link device roaming is performed on a non-access point multi-link device (MLD), wherein the communication method includes: The non-AP MLD establishes a multi-link connection with the first access point multi-link device AP MLD 1; The non-AP MLD requests roaming from the AP MLD 1 or the second access point multi-link device AP MLD 2; and After roaming is completed, the non-AP MLD establishes a multi-link connection with the AP MLD 2. The communication method according to claim 1, wherein, after the non-AP MLD establishes a multi-link connection with the AP MLD 2, the non-AP MLD disconnects the multi-link connection established with the AP MLD 1. The communication method according to claim 1, wherein, after the non-AP MLD establishes a multi-link connection with the AP MLD 2, the non-AP MLD still maintains a multi-link connection with the AP MLD 1. The communication method according to claim 1, wherein, before the non-AP MLD requests the AP MLD 1 to roam, the non-AP MLD sends a first frame to the AP MLD 2 and receives a second frame sent by the AP MLD 2, and the non-AP MLD determines whether to request the AP MLD 1 to roam based on the second frame. The communication method according to claim 4, wherein the first frame and the second frame include one of the following combinations: Request to Send (RTS) frames and Clear to Send (CTS) frames, Probe Request and Probe Response frames, Multilink Probe Request and Multilink Probe Response frames, or Fast Basic Service Set Switching (FT) Request and FT Response frames. The communication method according to claim 1, wherein, before the non-AP MLD requests roaming to the AP MLD 1, the non-AP MLD receives a second frame sent by the AP MLD 2, and the non-AP MLD determines whether to request roaming to the AP MLD 1 through the second frame. The communication method according to claim 6, wherein the second frame comprises a beacon frame. The communication method according to any one of claims 4 to 7, wherein the non-AP MLD determines, through the second frame, whether to request roaming from the AP MLD 1, comprising: The non-AP MLD confirms the link status information between the non-AP MLD and the AP MLD 2 through the second frame; and/or The non-AP MLD confirms the status information of the AP MLD 2 through the second frame. The communication method according to claim 8, wherein the link status information between the non-AP MLD and the AP MLD 2 includes a received signal strength indication RSSI, a channel state information CSI, a signal to interference plus noise ratio SINR, a signal to noise ratio SNR, a reference signal received power RSRP, and/or a reference signal received quality RSRQ. The communication method according to claim 8, wherein the status information of the AP MLD 2 includes a power status indication, a roaming available window, a roaming unavailable window, a basic service set BSS load, a channel load, a maximum number of supported sites STA/non-AP MLD, and/or mobile AP MLD information. The communication method according to claim 1, wherein the non-AP MLD requests the AP MLD 1 to roam, comprising: the non-AP MLD sends a first link reconfiguration frame to the AP MLD 1, and receives a second link reconfiguration frame sent by the AP MLD 1. The communication method according to claim 1, wherein the non-AP MLD requesting the AP MLD 2 to roam comprises: The non-AP MLD sends a first link reconfiguration frame to the AP MLD 2, and receives a second link reconfiguration frame sent by the AP MLD 2. The communication method according to claim 11 or 12, wherein the first link reconfiguration frame includes a reconfiguration multilink element. The communication method according to claim 13, wherein the presence bitmap subfield of the reconfigured multilink element includes a multilink device (MLD) medium access control (MAC) address presence field, an enhanced multilink (EML) capability presence field, an MLD capability and operation presence field, and/or a roaming information presence field, wherein: The MLD MAC address existence field is used to indicate whether the general information field of the reconfigured multi-link element contains an MLD MAC address field; The EML capability exists field is used to indicate whether the general information field of the reconfiguration multilink element has an EML capability field; The MLD capability and operation presence field is used to indicate whether the general information field of the reconfiguration multilink element has the MLD capability and operation field; The roaming information existence field is used to indicate whether a roaming information field exists in the general information field or the link information field of the reconfiguration multi-link element. The communication method according to claim 13, wherein the general information field of the reconfiguration multi-link element includes an MLD MAC address field, an EML capability field, an MLD capability and operation field, and a roaming information field, wherein: The MLD MAC address field is used to indicate the MLD MAC address of the AP MLD 2; The EML capability field is used to indicate the enhanced multi-link information of the non-AP MLD; The MLD Capability and Operation field is used to indicate the multi-link capability information and operation parameters of the non-AP MLD; The roaming information field is used to indicate one or more of the following information: channel information, resource scheduling information, power information, maximum number of transmit/receive spatial streams, enhanced distributed channel access EDCA parameter set, emergency preparedness communication service EPCS information, buffer status report BSR information, sequence number SN, data packet number PN, block confirmation BA session information, multi-access point AP mode, power information, target wake-up time TWT information, limited target wake-up time service phase R-TWT SP information, service identifier to link TID-to-Link mapping, extended capability information, and extremely high throughput EHT capability information. The communication method according to claim 15, wherein: The channel information is used to indicate channel information supported by the non-AP MLD and/or channel information corresponding to the link established by the non-AP MLD; The resource scheduling information is used to indicate the resource unit RU information used by the non-AP MLD to communicate with the AP MLD 1; The power information is used to indicate the transmit power information used by the non-AP MLD to communicate with the AP MLD 1; The maximum number of transmit/receive spatial streams is used to indicate the maximum number of transmit/receive spatial streams supported by the non-AP MLD; The enhanced distributed channel access EDCA parameter set is used to indicate the EDCA parameter set supported by the non-AP MLD or to indicate the EDCA parameter set established between the non-AP MLD and the AP MLD 1; The emergency preparedness communication service EPCS information is used to indicate EPCS capability information, EPCS subscription information, and EPCS activation status information supported by the non-AP MLD, and/or is used to instruct the non-AP MLD to request to establish an EPCS priority access permission and an EDCA parameter set for EPCS priority access with the AP MLD 2; The buffer status report BSR information is used to indicate the buffer status information of the non-AP MLD; The sequence number SN is used to indicate the SN of the frame between the non-AP MLD and the AP MLD 1; The packet number PN is used to indicate a PN that has been sent, a PN that is about to be sent, or a PN that has not been sent between the non-AP MLD and the AP MLD 1; The block acknowledgment (BA) session information is used to indicate the block acknowledgment (BA) session information established between the non-AP MLD and the AP MLD 1; the multi-access point (AP) mode is used to indicate the multi-AP collaboration mode supported by the non-AP MLD; The power information is used to indicate the sleep policy information and/or supported sleep mechanism of the non-AP MLD; The target wake-up time TWT information is used to indicate the TWT information established between the non-AP MLD and the AP MLD 1; The target wake-up time service phase R-TWT SP information is used to indicate the R-TWT SP information established between the non-AP MLD and the AP MLD 1; The mapping of the service identifier to the link TID-to-Link is used to indicate a TID-to-Link mapping scheme established between the non-AP MLD and the AP MLD 1, or is used to indicate a TID-to-Link mapping scheme for the link established between the non-AP MLD request and the AP MLD 2; The extended capability information is used to indicate the extended capability information of the non-AP MLD; The extremely high throughput EHT capability information is used to indicate the EHT capability information of the non-AP MLD. The communication method according to claim 13, wherein the reconfiguration multi-link element includes a per-site overview sub-element for carrying overview information of the non-AP MLD that initiates roaming. The communication method according to claim 17, wherein the per-station summary sub-element includes a STA control field, the STA control field includes a link identifier ID field, a reconfiguration operation type field, a new link ID presence field, and/or a roaming information presence field, wherein: The link ID field is used to indicate the link ID; The new link ID existence field is used to indicate whether the STA information field of the reconfigured multi-link element has a new link ID information field; The roaming information existence field is used to indicate whether the link information field of the reconfiguration multi-link element has a roaming information field. The communication method according to claim 18, wherein when the value indicated by the reconfiguration operation type field is 5, the reconfiguration operation type field is set to the meaning/operation of switching the link. The communication method according to claim 18, wherein when the reconfiguration operation type field indicates a switch link field and/or when the New Link ID Existence field of the STA Control field indicates presence, the Link ID field in the STA Control field indicates the link ID of the link disconnected from the non-AP MLD and the AP MLD 1, and the New Link ID Information field indicates the link ID of the link established between the non-AP MLD and the AP MLD 2. The communication method according to claim 18, wherein, when the reconfiguration operation type field indicates a switch link field and/or the new link ID existence field of the STA control field indicates existence, the link ID field in the STA control field indicates a link ID for establishing a connection between the non-AP MLD and the AP MLD 2, and the new link ID information field indicates a link ID for disconnecting the non-AP MLD from the AP MLD 1. The communication method according to claim 20 or 21, wherein the new link ID information field includes a link ID field, and the link ID field is used to indicate an identifier of a link, wherein the new link ID information field also includes a link ID extension field, and the link ID field and the link ID extension field jointly indicate a new link ID established between the non-AP MLD and the AP MLD 2. The communication method according to claim 11 or 12, wherein the second link reconfiguration frame includes a reconfiguration status list field. The communication method according to claim 23, wherein the reconfiguration status list field includes one or more reconfiguration status dual subfields, and the reconfiguration status dual subfield includes a link ID information field and a status field. The communication method according to claim 24, wherein the link ID information field includes a link ID subfield, the link ID subfield indicating a link ID of an AP, and indicating addition or deletion of the link ID of the AP in the first link reconfiguration frame. The communication method according to claim 24, wherein the status field includes a first status code, a second status code, a third status code, a fourth status code, and/or a fifth status code, wherein the first status code is used to indicate that the roaming request is rejected because the BSS load of the AP MLD 2 is greater than a first set value, the second status code is used to indicate that the roaming request is rejected because the channel load for establishing a link is greater than a second set value, the third status code is used to indicate that the roaming request is rejected because the time for requesting to establish a link does not match the window in which the AP MLD 2 is allowed to establish a link, the fourth status code is used to indicate that the system will enter a sleep state and will not accept roaming requests for the time being, and the fifth status code is used to indicate that the roaming request is rejected because the AP MLD 2 has reached the maximum number of STAs/non-AP MLDs supported. The communication method according to any one of claims 23 to 26, wherein the second link reconfiguration frame further includes a basic multi-link element, and the existence bit map field of the basic multi-link element includes a roaming information existence field, wherein the roaming information existence field is used to indicate whether a roaming information field exists in the general information field or the link information field of the basic multi-link element. The communication method according to claim 27, wherein the general information field of the basic multi-link element includes an MLD MAC address field for indicating the MLD MAC address of the AP MLD 2. The communication method according to claim 28, wherein the general information field of the basic multi-link element also includes a link ID information field, a BSS parameter change count field, a media synchronization delay information field, an EML capability field, an MLD capability and operation field, an AP MLD ID field, and/or an extended MLD capability and operation field, and the content indicated by the link ID information field, the BSS parameter change count field, the media synchronization delay information field, the EML capability field, the MLD capability and operation field, the AP MLD ID field, and/or the extended MLD capability and operation field refers to the relevant information between the non-AP MLD and the AP MLD 2. The communication method according to claim 27, wherein the roaming information field is used to indicate one or more of the following information: channel information, resource scheduling information, power information, maximum number of transmit/receive spatial streams, EDCA parameter set, EPCS information, BSR information, SN, PN, BA session information, multi-AP mode, power information, TWT information, R-TWT SP information, TID-to-Link mapping, extended capability information, and EHT capability information, wherein: The channel information is used to indicate channel information supported by the non-AP MLD and/or channel information corresponding to the link established by the non-AP MLD; The resource scheduling information is used to indicate the RU information used by the non-AP MLD to communicate with the AP MLD 1; The power information is used to indicate the transmit power information used by the non-AP MLD to communicate with the AP MLD 1; The maximum number of transmit/receive spatial streams is used to indicate the maximum number of transmit/receive spatial streams supported by the non-AP MLD; The EDCA parameter set is used to indicate the EDCA parameter set supported by the non-AP MLD or to indicate the EDCA parameter set established between the non-AP MLD and the AP MLD 1; The EPCS information is used to indicate EPCS capability information, EPCS subscription information, and EPCS activation status information supported by the non-AP MLD, and/or is used to instruct the non-AP MLD to request to establish an EPCS priority access permission and an EDCA parameter set for EPCS priority access with the AP MLD 2; The BSR information is used to indicate the cache status information of the non-AP MLD; The SN is used to indicate the SN of the frame between the non-AP MLD and the AP MLD 1; The PN is used to indicate the PN that has been sent, the PN that is about to be sent, or the PN that has not been sent between the non-AP MLD and the AP MLD 1; The BA session information is used to indicate the block acknowledgement session information established between the non-AP MLD and the AP MLD 1; The multi-AP mode is used to indicate the multi-AP collaboration mode supported by the non-AP MLD; The power information is used to indicate the sleep policy information and/or supported sleep mechanism of the non-AP MLD; The TWT information is used to indicate the TWT information established between the non-AP MLD and the AP MLD 1; The R-TWT SP information is used to indicate the R-TWT SP information established between the non-AP MLD and the AP MLD 1; The TID-to-Link mapping is used to indicate a TID-to-Link mapping scheme established between the non-AP MLD and the AP MLD 1, or is used to indicate a TID-to-Link mapping scheme for a link established between the non-AP MLD requesting and the AP MLD 2; The extended capability information is used to indicate the extended capability information of the non-AP MLD; The EHT capability information is used to indicate the EHT capability information of the non-AP MLD. The communication method of claim 29, wherein the link information field of the basic multilink element includes a per-site summary sub-element, the per-site summary sub-element includes a STA control field, and the STA control field includes a roaming information presence field. The communication method according to claim 31, wherein the roaming information existence field is used to indicate whether a roaming information field exists in the link information field of the basic multilink element. The communication method according to any one of claims 11 to 32 further includes the non-AP MLD starting a timer to confirm the time interval between the non-AP MLD sending the first link reconfiguration frame and the non-AP MLD receiving the second link reconfiguration frame. According to the communication method according to claim 33, wherein, after the non-AP MLD sends the first link reconfiguration frame, the timer is started; if the non-AP MLD receives the second link reconfiguration frame within the time corresponding to the timer, the non-AP MLD determines whether to roam through the second link reconfiguration frame. According to the communication method according to claim 33, wherein, after the non-AP MLD sends the first link reconfiguration frame, the timer is started; if the non-AP MLD does not receive the second link reconfiguration frame within the time corresponding to the timer, the non-AP MLD determines that the roaming has failed. A communication method based on multi-link device roaming is executed on an access point multi-link device (AP MLD), wherein the communication method includes: The first access point multi-link device AP MLD 1 sends a first link reconfiguration frame to a non-AP MLD to initiate roaming, wherein the first link reconfiguration frame is used to request the non-AP MLD to roam from AP MLD 1 to a second access point multi-link device AP MLD 2; and The AP MLD 1 receives the second link reconfiguration frame sent by the non-AP MLD to obtain the roaming result. The communication method according to claim 36, wherein, when the AP MLD 1 initiates a roaming operation or before the AP MLD 1 initiates a roaming operation, the AP MLD 1 and the AP MLD 2 perform context migration. The communication method according to claim 36, wherein the first link reconfiguration frame carries status information of the AP MLD 2. The communication method according to claim 36, further comprising the AP MLD 1 sending link reconfiguration confirmation information to the non-AP MLD. The communication method according to claim 36, wherein the first link reconfiguration frame and the second link reconfiguration frame include one of the following combinations: Request to Send (RTS) frames and Clear to Send (CTS) frames, Probe Request and Probe Response frames, Multilink Probe Request and Multilink Probe Response frames, or Fast Basic Service Set Switching (FT) Request and FT Response frames. The communication method according to claim 36, wherein the first link reconfiguration frame includes a reconfiguration multilink element. The communication method according to claim 41, wherein the presence bitmap subfield of the reconfigured multilink element includes a multilink device (MLD) medium access control (MAC) address presence field, an enhanced multilink (EML) capability presence field, an MLD capability and operation presence field, and/or a roaming information presence field, wherein: The MLD MAC address existence field is used to indicate whether the general information field of the reconfiguration multi-link element has an MLD MAC address field; The EML capability exists field is used to indicate whether the general information field of the reconfiguration multilink element has an EML capability field; The MLD capability and operation presence field is used to indicate whether the general information field of the reconfiguration multilink element has the MLD capability and operation field; The roaming information existence field is used to indicate whether a roaming information field exists in the general information field or the link information field of the reconfiguration multi-link element. The communication method according to claim 41, wherein the general information field of the reconfiguration multi-link element includes an MLD MAC address field, an EML capability field, an MLD capability and operation field, and a roaming information field, wherein: The MLD MAC address field is used to indicate the MLD MAC address of the AP MLD 2; The EML capability field is used to indicate the enhanced multi-link information of the non-AP MLD; The MLD Capability and Operation field is used to indicate the multi-link capability information and operation parameters of the non-AP MLD; The roaming information field is used to indicate one or more of the following information: channel information, resource scheduling information, power information, maximum number of transmit/receive spatial streams, enhanced distributed channel access EDCA parameter set, emergency preparedness communication service EPCS information, buffer status report BSR information, sequence number SN, data packet number PN, block confirmation BA session information, multi-access point AP mode, power information, target wake-up time TWT information, limited target wake-up time service phase R-TWT SP information, service identifier to link TID-to-Link mapping, extended capability information, and extremely high throughput EHT capability information. The communication method according to claim 43, wherein: The channel information is used to indicate channel information supported by the non-AP MLD and/or channel information corresponding to the link established by the non-AP MLD; The resource scheduling information is used to indicate the resource unit RU information used by the non-AP MLD to communicate with the AP MLD 1; The power information is used to indicate the transmit power information used by the non-AP MLD to communicate with the AP MLD 1; The maximum number of transmit/receive spatial streams is used to indicate the maximum number of transmit/receive spatial streams supported by the non-AP MLD; The enhanced distributed channel access EDCA parameter set is used to indicate the EDCA parameter set supported by the non-AP MLD or to indicate the EDCA parameter set established between the non-AP MLD and the AP MLD 1; The emergency preparedness communication service EPCS information is used to indicate EPCS capability information, EPCS subscription information, and EPCS activation status information supported by the non-AP MLD, and/or is used to instruct the non-AP MLD to request to establish an EPCS priority access permission and an EDCA parameter set for EPCS priority access with the AP MLD 2; The buffer status report BSR information is used to indicate the buffer status information of the non-AP MLD; The sequence number SN is used to indicate the SN of the frame between the non-AP MLD and the AP MLD 1; The packet number PN is used to indicate a PN that has been sent, a PN that is about to be sent, or a PN that has not been sent between the non-AP MLD and the AP MLD 1; The block acknowledgment (BA) session information is used to indicate the block acknowledgment (BA) session information established between the non-AP MLD and the AP MLD 1. The multi-access point AP mode is used to indicate the multi-AP collaboration mode supported by the non-AP MLD; The power information is used to indicate the sleep policy information and/or supported sleep mechanism of the non-AP MLD; The target wake-up time TWT information is used to indicate the TWT information established between the non-AP MLD and the AP MLD 1; The target wake-up time service phase R-TWT SP information is used to indicate the R-TWT SP information established between the non-AP MLD and the AP MLD 1; The mapping of the service identifier to the link TID-to-Link is used to indicate a TID-to-Link mapping scheme established between the non-AP MLD and the AP MLD 1, or is used to indicate a TID-to-Link mapping scheme for the link established between the non-AP MLD request and the AP MLD 2; The extended capability information is used to indicate the extended capability information of the non-AP MLD; The extremely high throughput EHT capability information is used to indicate the EHT capability information of the non-AP MLD. The communication method according to claim 41, wherein the reconfiguration multi-link element includes a per-site overview sub-element for carrying overview information of the non-AP MLD that initiates roaming. The communication method according to claim 45, wherein the per-station summary sub-element includes a STA control field, the STA control field including a link identifier ID field, a reconfiguration operation type field, a new link ID presence field, and/or a roaming information presence field, wherein: The link ID field is used to indicate the link ID; The new link ID existence field is used to indicate whether the STA information field of the reconfigured multi-link element has a new link ID information field; The roaming information existence field is used to indicate whether the link information field of the reconfiguration multi-link element has a roaming information field. The communication method according to claim 46, wherein, when the value indicated by the reconfiguration operation type field is 5, the reconfiguration operation type field is set to the meaning/operation of switching the link. The communication method according to claim 46, wherein, when the reconfiguration operation type field indicates a switch link field and/or the new link ID existence field of the STA control field indicates existence, the link ID field in the STA control field indicates a link ID of the non-AP MLD disconnected from the AP MLD 1, and the new link ID information field indicates a link ID of the non-AP MLD establishing a connection with the AP MLD 2. The communication method according to claim 46, wherein, when the reconfiguration operation type field indicates a switch link field and/or the new link ID existence field of the STA control field indicates existence, the link ID field in the STA control field indicates a link ID for establishing a connection between the non-AP MLD and the AP MLD 2, and the new link ID information field indicates a link ID for disconnecting the non-AP MLD from the AP MLD 1. The communication method according to claim 48 or 49, wherein the new link ID information field includes a link ID field, and the link ID field is used to indicate an identifier of a link, wherein the new link ID information field also includes a link ID extension field, and the link ID field and the link ID extension field jointly indicate a new link ID established between the non-AP MLD and the AP MLD 2. The communication method according to claim 49 or 50, wherein the second link reconfiguration frame includes a reconfiguration status list field. The communication method according to claim 51, wherein the reconfiguration status list field includes one or more reconfiguration status dual subfields, and the reconfiguration status dual subfield includes a link ID information field and a status field. The communication method according to claim 52, wherein the link ID information field includes a link ID subfield, the link ID subfield indicates the link ID of the AP, and the link ID of the AP is added or deleted in the first link reconfiguration frame. The communication method according to claim 52, wherein the status field includes a first status code, a second status code, a third status code, a fourth status code, and/or a fifth status code, wherein the first status code is used to indicate that the roaming request is rejected because the BSS load of the AP MLD 2 is greater than a first set value, the second status code is used to indicate that the roaming request is rejected because the channel load for establishing a link is greater than a second set value, the third status code is used to indicate that the roaming request is rejected because the time for requesting to establish a link does not match the window in which the AP MLD 2 is allowed to establish a link, the fourth status code is used to indicate that it will enter a sleep state and will not accept roaming requests for the time being, and the fifth status code is used to indicate that the roaming request is rejected because the AP MLD 2 has reached the maximum number of STAs/non-AP MLDs supported. The communication method according to any one of claims 51 to 54, wherein the second link reconfiguration frame further includes a basic multi-link element, and the existence bit map field of the basic multi-link element includes a roaming information existence field, wherein the roaming information existence field is used to indicate whether a roaming information field exists in the general information field or the link information field of the basic multi-link element. The communication method according to claim 55, wherein the general information field of the basic multi-link element includes an MLD MAC address field for indicating the MLD MAC address of the AP MLD 2. The communication method according to claim 56, wherein the general information field of the basic multi-link element also includes a link ID information field, a BSS parameter change count field, a media synchronization delay information field, an EML capability field, an MLD capability and operation field, an AP MLD ID field, and/or an extended MLD capability and operation field, and the content indicated by the link ID information field, the BSS parameter change count field, the media synchronization delay information field, the EML capability field, the MLD capability and operation field, the AP MLD ID field, and/or the extended MLD capability and operation field refers to the relevant information between the non-AP MLD and the AP MLD 2. The communication method according to claim 55, wherein the roaming information field is used to indicate one or more of the following information: channel information, resource scheduling information, power information, maximum number of transmit/receive spatial streams, EDCA parameter set, EPCS information, BSR information, SN, PN, BA session information, multi-AP mode, power information, TWT information, R-TWT SP information, TID-to-Link mapping, extended capability information, and EHT capability information, wherein: The channel information is used to indicate channel information supported by the non-AP MLD and/or channel information corresponding to the link established by the non-AP MLD; The resource scheduling information is used to indicate the RU information used by the non-AP MLD to communicate with the AP MLD 1; The power information is used to indicate the transmit power information used by the non-AP MLD to communicate with the AP MLD 1; The maximum number of transmit/receive spatial streams is used to indicate the maximum number of transmit/receive spatial streams supported by the non-AP MLD; The EDCA parameter set is used to indicate the EDCA parameter set supported by the non-AP MLD or to indicate the non-AP The EDCA parameter set established between MLD and the AP MLD 1; The EPCS information is used to indicate EPCS capability information, EPCS subscription information, and EPCS activation status information supported by the non-AP MLD, and/or to instruct the non-AP MLD to request to establish an EPCS priority access permission and an EDCA parameter set for EPCS priority access with the AP MLD 2; The BSR information is used to indicate the cache status information of the non-AP MLD; The SN is used to indicate the SN of the frame between the non-AP MLD and the AP MLD 1; The PN is used to indicate the PN that has been sent, the PN that is about to be sent, or the PN that has not been sent between the non-AP MLD and the AP MLD 1; The BA session information is used to indicate the block acknowledgement session information established between the non-AP MLD and the AP MLD 1; The multi-AP mode is used to indicate the multi-AP collaboration mode supported by the non-AP MLD; The power information is used to indicate the sleep policy information and/or supported sleep mechanism of the non-AP MLD; The TWT information is used to indicate the TWT information established between the non-AP MLD and the AP MLD 1; The R-TWT SP information is used to indicate the R-TWT SP information established between the non-AP MLD and the AP MLD 1; The TID-to-Link mapping is used to indicate a TID-to-Link mapping scheme established between the non-AP MLD and the AP MLD 1, or is used to indicate a TID-to-Link mapping scheme for a link established between the non-AP MLD requesting and the AP MLD 2; The extended capability information is used to indicate the extended capability information of the non-AP MLD; The EHT capability information is used to indicate the EHT capability information of the non-AP MLD. The communication method of claim 57, wherein the link information field of the basic multilink element includes a per-site summary sub-element, the per-site summary sub-element includes a STA control field, and the STA control field includes a roaming information presence field. The communication method according to claim 59, wherein the roaming information existence field is used to indicate whether a roaming information field exists in the link information field of the basic multilink element. The communication method according to any one of claims 39 to 60 further includes the AP MLD 1 starting a timer to confirm the time interval between the AP MLD 1 sending the first link reconfiguration frame and the AP MLD 1 receiving the second link reconfiguration frame. According to the communication method according to claim 61, wherein, after the AP MLD 1 sends the first link reconfiguration frame, the timer is started, and if the AP MLD 1 receives the second link reconfiguration frame within the time corresponding to the timer, the AP MLD 1 determines whether to roam through the second link reconfiguration frame. According to the communication method according to claim 61, wherein, after the AP MLD 1 sends the first link reconfiguration frame, the timer is started. If the AP MLD 1 does not receive the second link reconfiguration frame within the time corresponding to the timer, the AP MLD 1 determines that the roaming has failed. A communication method based on multi-link device roaming is executed on an access point multi-link device (AP MLD), wherein the communication method includes: The second access point multi-link device AP MLD 2 sends a first link reconfiguration frame to the non-AP MLD to initiate roaming, wherein the first link reconfiguration frame is used to request the non-AP MLD to roam from the first access point multi-link device AP MLD 1 to the AP MLD 2; and The AP MLD 2 receives the second link reconfiguration frame sent by the non-AP MLD to obtain the roaming result. The communication method according to claim 64, wherein, when the AP MLD 2 initiates the roaming operation or before the AP MLD 2 initiates the roaming operation, the AP MLD 2 performs context migration with the AP MLD 1. The communication method according to claim 64, wherein the AP MLD 2 sends the first link reconfiguration frame to the non-AP MLD to request link switching, and the first link reconfiguration frame includes information on disconnecting the link between the non-AP MLD and the AP MLD 1 and information on establishing the link between the non-AP MLD and the AP MLD 2. The communication method according to claim 64, wherein the AP MLD 2 sends the first link reconfiguration frame to the non-AP MLD to request to add a link, and the first link reconfiguration frame includes information on establishing a link between the non-AP MLD and the AP MLD 2. The communication method according to claim 64, wherein the first link reconfiguration frame and the second link reconfiguration frame include one of the following combinations: Request to Send (RTS) frames and Clear to Send (CTS) frames, Probe Request and Probe Response frames, Multilink Probe Request and Multilink Probe Response frames, or Fast Basic Service Set Switching (FT) Request and Fast Basic Service Set Switching (FT) Response frames. The communication method of claim 64, wherein the first link reconfiguration frame comprises a reconfiguration multilink element. The communication method according to claim 69, wherein the presence bitmap subfield of the reconfigured multilink element includes a multilink device (MLD) medium access control (MAC) address presence field, an enhanced multilink (EML) capability presence field, an MLD capability and operation presence field, and/or a roaming information presence field, wherein: The MLD MAC address existence field is used to indicate whether the general information field of the reconfigured multi-link element contains an MLD MAC address field; The EML capability exists field is used to indicate whether the general information field of the reconfiguration multilink element has an EML capability field; The MLD capability and operation presence field is used to indicate whether the general information field of the reconfiguration multilink element has the MLD capability and operation field; The roaming information existence field is used to indicate whether a roaming information field exists in the general information field or the link information field of the reconfiguration multi-link element. The communication method according to claim 69, wherein the general information field of the reconfiguration multi-link element includes an MLD MAC address field, an EML capability field, an MLD capability and operation field, and a roaming information field, wherein: The MLD MAC address field is used to indicate the MLD MAC address of the AP MLD 2; The EML capability field is used to indicate the enhanced multi-link information of the non-AP MLD; The MLD Capability and Operation field is used to indicate the multi-link capability information and operation parameters of the non-AP MLD; The roaming information field is used to indicate one or more of the following information: channel information, resource scheduling information, power information, maximum number of transmit/receive spatial streams, enhanced distributed channel access EDCA parameter set, emergency preparedness communication service EPCS information, buffer status report BSR information, sequence number SN, data packet number PN, block confirmation BA session information, multi-access point AP mode, power information, target wake-up time TWT information, limited target wake-up time service phase R-TWT SP information, service identifier to link TID-to-Link mapping, extended capability information, and extremely high throughput EHT capability information. The communication method according to claim 71, wherein: The channel information is used to indicate channel information supported by the non-AP MLD and/or channel information corresponding to the link established by the non-AP MLD; The resource scheduling information is used to indicate the resource unit RU information used by the non-AP MLD to communicate with the AP MLD 1; The power information is used to indicate the transmit power information used by the non-AP MLD to communicate with the AP MLD 1; The maximum number of transmit/receive spatial streams is used to indicate the maximum number of transmit/receive spatial streams supported by the non-AP MLD; The enhanced distributed channel access EDCA parameter set is used to indicate the EDCA parameter set supported by the non-AP MLD or to indicate the EDCA parameter set established between the non-AP MLD and the AP MLD 1; The emergency preparedness communication service EPCS information is used to indicate EPCS capability information, EPCS subscription information, and EPCS activation status information supported by the non-AP MLD, and/or is used to instruct the non-AP MLD to request to establish an EPCS priority access permission and an EDCA parameter set for EPCS priority access with the AP MLD 2; The buffer status report BSR information is used to indicate the buffer status information of the non-AP MLD; The sequence number SN is used to indicate the SN of the frame between the non-AP MLD and the AP MLD 1; The packet number PN is used to indicate a PN that has been sent, a PN that is about to be sent, or a PN that has not been sent between the non-AP MLD and the AP MLD 1; The block acknowledgment (BA) session information is used to indicate the block acknowledgment (BA) session information established between the non-AP MLD and the AP MLD 1. The multi-access point AP mode is used to indicate the multi-AP collaboration mode supported by the non-AP MLD; The power information is used to indicate the sleep policy information and/or supported sleep mechanism of the non-AP MLD; The target wake-up time TWT information is used to indicate the TWT information established between the non-AP MLD and the AP MLD 1; The target wake-up time service phase R-TWT SP information is used to indicate the R-TWT SP information established between the non-AP MLD and the AP MLD 1; The mapping of the service identifier to the link TID-to-Link is used to indicate a TID-to-Link mapping scheme established between the non-AP MLD and the AP MLD 1, or is used to indicate a TID-to-Link mapping scheme for the link established between the non-AP MLD request and the AP MLD 2; The extended capability information is used to indicate the extended capability information of the non-AP MLD; The extremely high throughput EHT capability information is used to indicate the EHT capability information of the non-AP MLD. The communication method according to claim 69, wherein the reconfiguration multi-link element includes a per-site overview sub-element for carrying overview information of the non-AP MLD that initiates roaming. The communication method of claim 73, wherein the per-station summary sub-element includes a STA control field, The STA Control field includes a Link Identifier ID field, a Reconfiguration Operation Type field, a New Link ID Present field, and/or a Roaming Information Present field, where: The link ID field is used to indicate the link ID; The new link ID existence field is used to indicate whether the STA information field of the reconfigured multi-link element has a new link ID information field; The roaming information existence field is used to indicate whether the link information field of the reconfiguration multi-link element has a roaming information field. The communication method according to claim 74, wherein, when the value indicated by the reconfiguration operation type field is 5, the reconfiguration operation type field is set to the meaning/operation of switching the link. The communication method according to claim 74, wherein, when the reconfiguration operation type field indicates a switch link field and/or the new link ID existence field of the STA control field indicates existence, the link ID field in the STA control field indicates a link ID of the non-AP MLD disconnected from the AP MLD 1, and the new link ID information field indicates a link ID of the non-AP MLD connected to the AP MLD 2. The communication method according to claim 74, wherein, when the reconfiguration operation type field indicates a switch link field and/or the new link ID existence field of the STA control field indicates existence, the link ID field in the STA control field indicates a link ID for establishing a connection between the non-AP MLD and the AP MLD 2, and the new link ID information field indicates a link ID for disconnecting the non-AP MLD from the AP MLD 1. The communication method according to claim 76 or 77, wherein the new link ID information field includes a link ID field, and the link ID field is used to indicate an identifier of the link, wherein the new link ID information field also includes a link ID extension field, and the link ID field and the link ID extension field jointly indicate a new link ID established between the non-AP MLD and the AP MLD 2. The communication method of claim 64, wherein the second link reconfiguration frame includes a reconfiguration status list field. The communication method according to claim 79, wherein the reconfiguration status list field includes one or more reconfiguration status dual subfields, and the reconfiguration status dual subfield includes a link ID information field and a status field. The communication method according to claim 80, wherein the link ID information field includes a link ID subfield, the link ID subfield indicates the link ID of the AP, and the link ID of the AP is added or deleted in the first link reconfiguration frame. The communication method according to claim 80, wherein the status field includes a first status code, a second status code, a third status code, a fourth status code, and/or a fifth status code, wherein the first status code is used to indicate that the roaming request is rejected because the BSS load of the AP MLD 2 is greater than a first set value, the second status code is used to indicate that the roaming request is rejected because the channel load for establishing a link is greater than a second set value, the third status code is used to indicate that the roaming request is rejected because the time for requesting to establish a link does not match the window in which the AP MLD 2 is allowed to establish a link, the fourth status code is used to indicate that it will enter a sleep state and will not accept roaming requests for the time being, and the fifth status code is used to indicate that the roaming request is rejected because the AP MLD 2 has reached the maximum number of STAs/non-AP MLDs supported. The communication method according to any one of claims 79 to 82, wherein the second link reconfiguration frame further includes a basic multi-link element, and the existence bit map field of the basic multi-link element includes a roaming information existence field, wherein the roaming information existence field is used to indicate whether a roaming information field exists in the general information field or the link information field of the basic multi-link element. The communication method according to claim 83, wherein the general information field of the basic multi-link element includes an MLD MAC address field for indicating the MLD MAC address of the AP MLD 2. The communication method according to claim 84, wherein the general information field of the basic multi-link element also includes a link ID information field, a BSS parameter change count field, a media synchronization delay information field, an EML capability field, an MLD capability and operation field, an AP MLD ID field, and/or an extended MLD capability and operation field, and the content indicated by the link ID information field, the BSS parameter change count field, the media synchronization delay information field, the EML capability field, the MLD capability and operation field, the AP MLD ID field, and/or the extended MLD capability and operation field refers to the relevant information between the non-AP MLD and the AP MLD 2. The communication method according to claim 83, wherein the roaming information field is used to indicate one or more of the following information: channel information, resource scheduling information, power information, maximum number of transmit/receive spatial streams, EDCA parameter set, EPCS information, BSR information, SN, PN, BA session information, multi-AP mode, power information, TWT information, R-TWT SP information, TID-to-Link mapping, extended capability information, and EHT capability information, wherein: The channel information is used to indicate channel information supported by the non-AP MLD and/or channel information corresponding to the link established by the non-AP MLD; The resource scheduling information is used to indicate the RU information used by the non-AP MLD to communicate with the AP MLD 1; The power information is used to indicate the transmit power information used by the non-AP MLD to communicate with the AP MLD 1; The maximum number of transmit/receive spatial streams is used to indicate the maximum number of transmit/receive spatial streams supported by the non-AP MLD; The EDCA parameter set is used to indicate the EDCA parameter set supported by the non-AP MLD or to indicate the EDCA parameter set established between the non-AP MLD and the AP MLD 1; The EPCS information is used to indicate EPCS capability information, EPCS subscription information, and EPCS activation status information supported by the non-AP MLD, and/or to instruct the non-AP MLD to request to establish an EPCS priority access permission and an EDCA parameter set for EPCS priority access with the AP MLD 2; The BSR information is used to indicate the cache status information of the non-AP MLD; The SN is used to indicate the SN of the frame between the non-AP MLD and the AP MLD 1; The PN is used to indicate the PN that has been sent, the PN that is about to be sent, or the PN that has not been sent between the non-AP MLD and the AP MLD 1; The BA session information is used to indicate the block acknowledgement session information established between the non-AP MLD and the AP MLD 1; The multi-AP mode is used to indicate the multi-AP collaboration mode supported by the non-AP MLD; The power information is used to indicate the sleep policy information and/or supported sleep mechanism of the non-AP MLD; The TWT information is used to indicate the TWT information established between the non-AP MLD and the AP MLD 1; The R-TWT SP information is used to indicate the R-TWT SP information established between the non-AP MLD and the AP MLD 1; The TID-to-Link mapping is used to indicate a TID-to-Link mapping scheme established between the non-AP MLD and the AP MLD 1, or is used to indicate a TID-to-Link mapping scheme for a link established between the non-AP MLD requesting and the AP MLD 2; The extended capability information is used to indicate the extended capability information of the non-AP MLD; The EHT capability information is used to indicate the EHT capability information of the non-AP MLD. The communication method of claim 85, wherein the link information field of the basic multilink element includes a per-site summary sub-element, the per-site summary sub-element includes a STA control field, and the STA control field includes a roaming information presence field. The communication method according to claim 87, wherein the roaming information existence field is used to indicate whether a roaming information field exists in the link information field of the basic multilink element. The communication method according to any one of claims 64 to 88 further includes the AP MLD 2 starting a timer to confirm the time interval between the AP MLD 2 sending the first link reconfiguration frame and the AP MLD 2 receiving the second link reconfiguration frame. According to the communication method according to claim 89, the AP MLD 2 starts the timer after sending the first link reconfiguration frame. If the AP MLD 2 receives the second link reconfiguration frame within the time corresponding to the timer, the AP MLD 2 determines whether to roam through the second link reconfiguration frame. According to the communication method according to claim 89, the AP MLD 2 starts the timer after sending the first link reconfiguration frame. If the AP MLD 2 does not receive the second link reconfiguration frame within the time corresponding to the timer, the AP MLD 2 determines that the roaming has failed. A context migration method based on multi-link device roaming is executed on an access point multi-link device (AP MLD), wherein the context migration method includes: The first access point multi-link device AP MLD 1 establishes a backhaul link with the second access point multi-link device AP MLD 2; The AP MLD 1 exchanges context migration information with the AP MLD 2 through the backhaul link. The context migration method according to claim 92, wherein the backhaul link is a wireless backhaul link. The context migration method according to claim 93, wherein the context migration information includes a first frame and a second frame, the first frame is used to transmit information of a non-access point multi-link device non-AP MLD roaming between the AP MLD 1 and the AP MLD 2, the second frame confirms the acceptance of the first frame, the second frame modifies or suggests the information carried by the first frame, and/or the second frame carries the information requested by the first frame. The context migration method according to claim 93, wherein the context migration information includes a first frame and a response frame, the first frame is an action frame, the action frame is used to transmit information of a non-access point multi-link device non-AP MLD roaming between the AP MLD 1 and the AP MLD 2, and the response frame responds to receiving the first frame. The context migration method according to claim 93, wherein the context migration information includes a first frame, the first frame is an action frame, and the action frame is used to transmit information of a non-access point multi-link device (non-AP MLD) roaming between the AP MLD 1 and the AP MLD 2, and the receiving party does not need to confirm the receipt of the action frame. According to the context migration method according to any one of claims 94 to 96, the first frame is used to indicate one or more of the following information: channel information, resource scheduling information, power information, maximum number of transmit/receive spatial streams, enhanced distributed channel access EDCA parameter set, emergency preparedness communication service EPCS information, buffer status report BSR information, sequence number SN, data packet number PN, block acknowledgment BA session information, multi-access point AP mode, power information, target wake-up time TWT information, target wake-up time service phase R-TWT SP information, service identifier to link TID-to-Link mapping, extended capability information, extremely high throughput EHT capability information, enhanced multi-link EML capability information, MLD capability and operation information, new link ID, and data to be transmitted. The context migration method according to claim 97, wherein: The channel information is used to indicate channel information supported by the non-AP MLD and/or channel information corresponding to the link established by the non-AP MLD; The resource scheduling information is used to indicate the resource unit RU information used by the non-AP MLD to communicate with the AP MLD 1; The power information is used to indicate the transmit power information used by the non-AP MLD to communicate with the AP MLD 1; The maximum number of transmit/receive spatial streams is used to indicate the maximum number of transmit/receive spatial streams supported by the non-AP MLD; The EDCA parameter set is used to indicate the EDCA parameter set supported by the non-AP MLD or to indicate the EDCA parameter set established between the non-AP MLD and the AP MLD 1; The EPCS information is used to indicate EPCS capability information, EPCS subscription information, and EPCS activation status information supported by the non-AP MLD, and/or to instruct the non-AP MLD to request to establish an EPCS priority access permission and an EDCA parameter set for EPCS priority access with the AP MLD 2; The BSR information is used to indicate the cache status information of the non-AP MLD; The SN is used to indicate the SN of the frame between the non-AP MLD and the AP MLD 1; The PN is used to indicate the PN that has been sent, the PN that is about to be sent, or the PN that has not been sent between the non-AP MLD and the AP MLD 1; The BA session information is used to indicate the block acknowledgement session information established between the non-AP MLD and the AP MLD 1; The multi-AP mode is used to indicate the multi-AP collaboration mode supported by the non-AP MLD; The power information is used to indicate the sleep policy information and/or supported sleep mechanism of the non-AP MLD; The TWT information is used to indicate the TWT information established between the non-AP MLD and the AP MLD 1; The R-TWT SP information is used to indicate the R-TWT SP information established between the non-AP MLD and the AP MLD 1; The TID-to-Link mapping is used to indicate a TID-to-Link mapping scheme established between the non-AP MLD and the AP MLD 1, or is used to indicate a TID-to-Link mapping scheme for a link established between the non-AP MLD requesting and the AP MLD 2; The extended capability information is used to indicate the extended capability information of the non-AP MLD; The EHT capability information is used to indicate the EHT capability information of the non-AP MLD; The EML capability information is used to indicate the EML capability information of the non-AP MLD; The MLD capability and operation information is used to indicate the MLD capability and operation information of the non-AP MLD; The new link ID indicates the link ID for establishing a connection between the non-AP MLD and the AP MLD 2; The data to be transmitted is used to indicate the unsent data cached by the AP MLD 1 to the non-AP MLD to which roaming is about to be performed. The context migration method according to claim 92, wherein the backhaul link is a wired backhaul link. The context migration method according to claim 99, wherein the context migration information includes one or more of the following information: channel information, resource scheduling information, power information, maximum number of transmit/receive spatial streams, enhanced distributed channel access EDCA parameter set, emergency preparedness communication service EPCS information, cache status report BSR information, sequence number SN, data packet number PN, block acknowledgment BA session information, multi-access point AP mode, power information, target wake-up time TWT information, target wake-up time service phase R-TWT SP information, service identifier to link TID-to-Link mapping, extended capability information, extremely high throughput EHT capability information, enhanced multi-link EML capability information, MLD capability and operation information, new link ID, and data to be transmitted. The context migration method according to claim 100, wherein: The channel information is used to indicate channel information supported by the non-AP MLD and/or channel information corresponding to the link established by the non-AP MLD; The resource scheduling information is used to indicate resource unit RU information used by the non-AP MLD to communicate with the AP MLD 1; The power information is used to indicate the transmit power information used by the non-AP MLD to communicate with the AP MLD 1; The maximum number of transmit/receive spatial streams is used to indicate the maximum number of transmit/receive spatial streams supported by the non-AP MLD; The EDCA parameter set is used to indicate the EDCA parameter set supported by the non-AP MLD or to indicate the EDCA parameter set established between the non-AP MLD and the AP MLD 1; The EPCS information is used to indicate EPCS capability information, EPCS subscription information, and EPCS activation status information supported by the non-AP MLD, and/or to instruct the non-AP MLD to request to establish an EPCS priority access permission and an EDCA parameter set for EPCS priority access with the AP MLD 2; The BSR information is used to indicate the cache status information of the non-AP MLD; The SN is used to indicate the SN of the frame between the non-AP MLD and the AP MLD 1; The PN is used to indicate the PN that has been sent, the PN that is about to be sent, or the PN that has not been sent between the non-AP MLD and the AP MLD 1; The BA session information is used to indicate the block acknowledgement session information established between the non-AP MLD and the AP MLD 1; The multi-AP mode is used to indicate the multi-AP collaboration mode supported by the non-AP MLD; The power information is used to indicate the sleep policy information and/or supported sleep mechanism of the non-AP MLD; The TWT information is used to indicate the TWT information established between the non-AP MLD and the AP MLD 1; The R-TWT SP information is used to indicate the R-TWT SP information established between the non-AP MLD and the AP MLD 1; The TID-to-Link mapping is used to indicate a TID-to-Link mapping scheme established between the non-AP MLD and the AP MLD 1, or is used to indicate a TID-to-Link mapping scheme for a link established between the non-AP MLD requesting and the AP MLD 2; The extended capability information is used to indicate the extended capability information of the non-AP MLD; The EHT capability information is used to indicate the EHT capability information of the non-AP MLD; The EML capability information is used to indicate the EML capability information of the non-AP MLD; The MLD capability and operation information is used to indicate the MLD capability and operation information of the non-AP MLD; The new link ID indicates the link ID for establishing a connection between the non-AP MLD and the AP MLD 2; The data to be transmitted is used to indicate the unsent data cached by the AP MLD 1 to the non-AP MLD to which roaming is about to be performed. An information conversion method based on multi-link device roaming is performed on a non-access point multi-link device (MLD), wherein the information conversion method includes: When a non-AP MLD roams between a first access point multi-link device AP MLD 1 and a second access point multi-link device AP MLD 2, the non-AP MLD converts information between the non-AP MLD and the AP MLD 1 to adapt to the communication between the non-AP MLD and the AP MLD 2. The information conversion method according to claim 102, wherein the information between the non-AP MLD and the AP MLD 1 includes one or more of the following information: channel information, resource scheduling information, power information, maximum number of transmit/receive spatial streams, enhanced distributed channel access EDCA parameter set, emergency preparedness communication service EPCS information, buffer status report BSR information, sequence number SN, data packet number PN, block acknowledgment BA session information, multi-access point AP mode, power information, target wake-up time TWT information, limited target wake-up time service phase R-TWT SP information, service identifier to link TID-to-Link mapping, extended capability information, extremely high throughput EHT capability information, enhanced multi-link EML capability information, MLD capability and operation information, and new link ID. The information conversion method according to claim 103, wherein: The channel information is used to indicate channel information supported by the non-AP MLD and/or channel information corresponding to the link established by the non-AP MLD; The resource scheduling information is used to indicate the resource unit RU information used by the non-AP MLD to communicate with the AP MLD 1; The power information is used to indicate the transmit power information used by the non-AP MLD to communicate with the AP MLD 1; The maximum number of transmit/receive spatial streams is used to indicate the maximum number of transmit/receive spatial streams supported by the non-AP MLD; The EDCA parameter set is used to indicate the EDCA parameter set supported by the non-AP MLD or to indicate the EDCA parameter set established between the non-AP MLD and the AP MLD 1; The EPCS information is used to indicate EPCS capability information, EPCS subscription information, and EPCS activation status information supported by the non-AP MLD, and/or to instruct the non-AP MLD to request to establish an EPCS priority access permission and an EDCA parameter set for EPCS priority access with the AP MLD 2; The BSR information is used to indicate the cache status information of the non-AP MLD; The SN is used to indicate the SN of the frame between the non-AP MLD and the AP MLD 1; The PN is used to indicate the PN that has been sent, the PN that is about to be sent, or the PN that has not been sent between the non-AP MLD and the AP MLD 1; The BA session information is used to indicate the block acknowledgement session information established between the non-AP MLD and the AP MLD 1; The multi-AP mode is used to indicate the multi-AP collaboration mode supported by the non-AP MLD; The power information is used to indicate the sleep policy information and/or supported sleep mechanism of the non-AP MLD; The TWT information is used to indicate the TWT information established between the non-AP MLD and the AP MLD 1; The R-TWT SP information is used to indicate the R-TWT SP information established between the non-AP MLD and the AP MLD 1; The TID-to-Link mapping is used to indicate a TID-to-Link mapping scheme established between the non-AP MLD and the AP MLD 1, or is used to indicate a TID-to-Link mapping scheme for a link established between the non-AP MLD requesting and the AP MLD 2; The extended capability information is used to indicate the extended capability information of the non-AP MLD; The EHT capability information is used to indicate the EHT capability information of the non-AP MLD; The EML capability information is used to indicate the EML capability information of the non-AP MLD; The MLD capability and operation information is used to indicate the MLD capability and operation information of the non-AP MLD; The new link ID indicates the link ID for establishing a connection between the non-AP MLD and the AP MLD 2. A communication method based on multi-link device roaming is performed on a non-access point multi-link device (MLD), wherein the communication method includes: After the non-AP MLD roams from the first access point multi-link device AP MLD 1 to the second access point multi-link device AP MLD 2, the non-AP MLD confirms the roaming result. The communication method according to claim 105, wherein the non-AP MLD confirming the roaming result comprises: The non-AP MLD sends a roaming confirmation message to the AP MLD 2 and receives a roaming response message sent by the AP MLD 2. The communication method according to claim 106, wherein, after the non-AP MLD receives the roaming response information sent by the AP MLD 2, the non-AP MLD sends a roaming completion information to the AP MLD 1. The communication method according to claim 107, wherein the roaming completion information includes a roaming MLD address field for indicating the MLD MAC address of the non-AP MLD that completes the roaming. The communication method according to claim 106, wherein the roaming confirmation information and the roaming response information include one of the following combinations: a request to send RTS frame and a clear to send CTS frame, a probe request frame and a probe response frame, a multi-link probe request frame and a multi-link probe response frame, a buffer status report polling BSRP trigger frame and a triggered physical layer protocol data unit TB PPDU with a buffer status report BSR, a multi-user request to send frame MU-RTS trigger frame and a CTS frame, or a data frame and a response frame. The communication method according to claim 106, wherein the frame body of the roaming confirmation information carries the converted information between the non-AP MLD and the AP MLD 1 to adapt the communication between the non-AP MLD and the AP MLD 2. The communication method according to claim 110, wherein the information between the converted non-AP MLD and the AP MLD 1 includes one or more of the following information: channel information, resource scheduling information, power information, maximum number of transmit/receive spatial streams, enhanced distributed channel access EDCA parameter set, emergency preparedness communication service EPCS information, buffer status report BSR information, sequence number SN, data packet number PN, block acknowledgment BA session information, multi-access point AP mode, power information, target wake-up time TWT information, limited target wake-up time service phase R-TWT SP information, service identifier to link TID-to-Link mapping, extended capability information, extremely high throughput EHT capability information, enhanced multi-link EML capability information, MLD capability and operation information, and new link ID. The communication method according to claim 101, wherein: The channel information is used to indicate channel information supported by the non-AP MLD and/or channel information corresponding to the link established by the non-AP MLD; The resource scheduling information is used to indicate the resource unit RU information used by the non-AP MLD to communicate with the AP MLD 1; The power information is used to indicate the transmit power information used by the non-AP MLD to communicate with the AP MLD 1; The maximum number of transmit/receive spatial streams is used to indicate the maximum number of transmit/receive spatial streams supported by the non-AP MLD; The EDCA parameter set is used to indicate the EDCA parameter set supported by the non-AP MLD or to indicate the EDCA parameter set established between the non-AP MLD and the AP MLD 1; The EPCS information is used to indicate the EPCS capability information, EPCS subscription information, and EPCS enablement information supported by the non-AP MLD. Status information, and/or an EDCA parameter set for instructing the non-AP MLD to request to establish an EPCS priority access permission and EPCS priority access with the AP MLD 2; The BSR information is used to indicate the cache status information of the non-AP MLD; The SN is used to indicate the SN of the frame between the non-AP MLD and the AP MLD 1; The PN is used to indicate the PN that has been sent, the PN that is about to be sent, or the PN that has not been sent between the non-AP MLD and the AP MLD 1; The BA session information is used to indicate the block acknowledgement session information established between the non-AP MLD and the AP MLD 1; The multi-AP mode is used to indicate the multi-AP collaboration mode supported by the non-AP MLD; The power information is used to indicate the sleep policy information and/or supported sleep mechanism of the non-AP MLD; The TWT information is used to indicate the TWT information established between the non-AP MLD and the AP MLD 1; The R-TWT SP information is used to indicate the R-TWT SP information established between the non-AP MLD and the AP MLD 1; The TID-to-Link mapping is used to indicate a TID-to-Link mapping scheme established between the non-AP MLD and the AP MLD 1, or is used to indicate a TID-to-Link mapping scheme for a link established between the non-AP MLD requesting and the AP MLD 2; The extended capability information is used to indicate the extended capability information of the non-AP MLD; The EHT capability information is used to indicate the EHT capability information of the non-AP MLD; The EML capability information is used to indicate the EML capability information of the non-AP MLD; The MLD capability and operation information is used to indicate the MLD capability and operation information of the non-AP MLD; The new link ID indicates the link ID for establishing a connection between the non-AP MLD and the AP MLD 2. The communication method according to claim 106, further comprising the non-AP MLD performing one or more of the following operations based on the roaming confirmation information: Switch the working primary channel and working bandwidth to the primary channel number and working bandwidth indicated by AP MLD 2; said adjusting the clock information to the clock information of said AP MLD 2; Prepare channel access parameters according to the EDCA parameter set indicated by AP MLD 2; Setting the EPCS priority access to an on/off state according to the EPCS information indicated by the AP MLD 2; if the state is on, performing contention transmission of EPCS services according to the EDCA parameter set for the EPCS priority access indicated by the AP MLD 2; Marking the SN of the next frame communicated with AP MLD 2 according to the SN indicated by AP MLD 2; Marking the PN of the next media access control protocol data unit (MPDU) communicated with the AP MLD 2 according to the PN indicated by the AP MLD 2; updating the BA scoreboard for the next data transmission communicated with the AP MLD 2 according to the BA session information indicated by the AP MLD 2; Prepare channel resource preemption according to the multi-AP mode indicated by AP MLD 2, thereby initiating the corresponding multi-AP collaboration request; Adjust the sleep window, sleep interval, and clock information according to the power information indicated by AP MLD 2; Adjust the TWT SP information according to the TWT information and clock information indicated by the AP MLD 2; Adjust the R-TWT SP information according to the R-TWT information and clock information indicated by the AP MLD 2, and remain silent/dormant before the response R-TWT SP information begins; Remap its own services to the new link according to the TID-to-Link mapping indicated by AP MLD 2 and prepare for transmission; Enable/disable extended capabilities according to the extended capabilities information indicated by the AP MLD 2; and Enable/disable EHT capability according to the EHT capability information indicated by the AP MLD 2. A communication method based on multi-link device roaming is executed on an access point multi-link device (AP MLD), wherein the communication method includes: After the non-access point multi-link device non-AP MLD roams from the first access point multi-link device AP MLD 1 to the second access point multi-link device AP MLD 2, the AP MLD 2 confirms the roaming result. The communication method according to claim 114, wherein the result of the AP MLD 2 confirming the roaming includes: The AP MLD 2 sends a roaming confirmation message to the non-AP MLD and receives a roaming response message sent by the non-AP MLD. The communication method according to claim 115, wherein, after the AP MLD 2 receives the roaming response information sent by the non-AP MLD, the AP MLD 2 sends a roaming completion information to the AP MLD 1. The communication method according to claim 116, wherein the roaming completion information includes a roaming MLD address field for Indicates the MLD MAC address of the non-AP MLD that completes roaming. The communication method according to claim 115, wherein the roaming confirmation information and the roaming response information include one of the following combinations: a request to send RTS frame and a clear to send CTS frame, a probe request frame and a probe response frame, a multi-link probe request frame and a multi-link probe response frame, a buffer status report polling BSRP trigger frame and a triggered physical layer protocol data unit TB PPDU with a buffer status report BSR, a multi-user request to send frame MU-RTS trigger frame and a CTS frame, or a data frame and a response frame. The communication method according to claim 115, wherein the frame body of the roaming confirmation information carries the converted information between the non-AP MLD and the AP MLD 1 to adapt the communication between the non-AP MLD and the AP MLD 2. The communication method according to claim 119, wherein the information between the converted non-AP MLD and the AP MLD 1 includes one or more of the following information: channel information, resource scheduling information, power information, maximum number of transmit/receive spatial streams, enhanced distributed channel access EDCA parameter set, emergency preparedness communication service EPCS information, cache status report BSR information, sequence number SN, data packet number PN, block acknowledgment BA session information, multi-access point AP mode, power information, target wake-up time TWT information, limited target wake-up time service phase R-TWT SP information, service identifier to link TID-to-Link mapping, extended capability information, extremely high throughput EHT capability information, enhanced multi-link EML capability information, MLD capability and operation information, and new link ID. The communication method according to claim 120, wherein: The channel information is used to indicate channel information supported by the non-AP MLD and/or channel information corresponding to the link established by the non-AP MLD; The resource scheduling information is used to indicate the resource unit RU information used by the non-AP MLD to communicate with the AP MLD 1; The power information is used to indicate the transmit power information used by the non-AP MLD to communicate with the AP MLD 1; The maximum number of transmit/receive spatial streams is used to indicate the maximum number of transmit/receive spatial streams supported by the non-AP MLD; The EDCA parameter set is used to indicate the EDCA parameter set supported by the non-AP MLD or to indicate the EDCA parameter set established between the non-AP MLD and the AP MLD 1; The EPCS information is used to indicate EPCS capability information, EPCS subscription information, and EPCS activation status information supported by the non-AP MLD, and/or to instruct the non-AP MLD to request to establish an EPCS priority access permission and an EDCA parameter set for EPCS priority access with the AP MLD 2; The BSR information is used to indicate the cache status information of the non-AP MLD; The SN is used to indicate the SN of the frame between the non-AP MLD and the AP MLD 1; The PN is used to indicate the PN that has been sent, the PN that is about to be sent, or the PN that has not been sent between the non-AP MLD and the AP MLD 1; The BA session information is used to indicate the block acknowledgement session information established between the non-AP MLD and the AP MLD 1; The multi-AP mode is used to indicate the multi-AP collaboration mode supported by the non-AP MLD; The power information is used to indicate the sleep policy information and/or supported sleep mechanism of the non-AP MLD; The TWT information is used to indicate the TWT information established between the non-AP MLD and the AP MLD 1; The R-TWT SP information is used to indicate the R-TWT SP information established between the non-AP MLD and the AP MLD 1; The TID-to-Link mapping is used to indicate a TID-to-Link mapping scheme established between the non-AP MLD and the AP MLD 1, or is used to indicate a TID-to-Link mapping scheme for a link established between the non-AP MLD requesting and the AP MLD 2; The extended capability information is used to indicate the extended capability information of the non-AP MLD; The EHT capability information is used to indicate the EHT capability information of the non-AP MLD; The EML capability information is used to indicate the EML capability information of the non-AP MLD; The MLD capability and operation information is used to indicate the MLD capability and operation information of the non-AP MLD; The new link ID indicates the link ID for establishing a connection between the non-AP MLD and the AP MLD 2. The communication method according to claim 114, wherein the AP MLD 2 is further included in scheduling the non-AP MLD transmission in combination with the working status of the non-AP MLD. A wireless communication device comprises: a processor and a memory, wherein the memory is used to store a computer program, and the processor is used to call and run the computer program stored in the memory to execute the method according to any one of claims 1 to 122.