Multi-link device communication method, communication apparatus, chip, computer-readable storage medium, and computer program product

Abstract

The present application provides a multi-link device (MLD) communication method. The method can support IEEE protocols, such as an 802.11be / Wi-Fi 7 / Wi-Fi 8 protocol, an IEEE 802.11 Integrated mmWave protocol, an IEEE 802.11bf / sensing protocol, or an IEEE 802.15 / UWB protocol; and the method can also support a NearLink protocol. The method comprises: generating a request frame, the request frame being used for requesting to roam to a target AP MLD, the request frame comprising first indication information, and the first indication information being used for determining the target AP MLD; and sending the request frame to a first AP MLD. In embodiments of the present application, a non-AP MLD sends a request frame to a first AP MLD, so as to roam the non-AP MLD to a target AP MLD.

Description

Multi-link device communication method, communication device, chip, computer-readable storage medium, and computer program product

[0001] This application claims priority to a Chinese patent application filed on March 7, 2024, with application number 202410266240.X, filed with the State Intellectual Property Office of China, and entitled “Method, communication device, chip, computer-readable storage medium and computer program product for multi-link device communication,” the entire contents of which are incorporated herein by reference. Technical Field

[0002] The present application relates to the field of communications, and in particular to a method, a communication device, a chip, a computer-readable storage medium, and a computer program product for multi-link device communications. Background Art

[0003] Wireless local area network (WLAN) roaming or wireless fidelity (Wi-Fi) roaming refers to the process of a wireless terminal or station (STA) moving from one access point (AP) to another, that is, the process of the wireless terminal or STA moving from one basic service set (BSS) to another. WLAN roaming or Wi-Fi roaming means that a STA can move freely within a Wi-Fi network belonging to the same extended service set (ESS), such as switching from one BSS to another in the same ESS. WLAN roaming or Wi-Fi roaming includes STA roaming and non-AP multi-link device (non-AP MLD) roaming, that is, the switching of a non-AP MLD from one access point multi-link device (AP MLD) to another.

[0004] The roaming mechanism currently defined in the protocol does not support packet retransmission. This means that packet loss and prolonged transmission interruptions may occur during roaming, resulting in a poor user experience. Improving the user roaming experience is a pressing issue. Summary of the Invention

[0005] The embodiments of the present application disclose a method, a communication device, a chip, a computer-readable storage medium, and a computer program product for multi-link device communication, which can implement roaming supporting packet resumption.

[0006] In a first aspect, an embodiment of the present application provides a method for multi-link device communication, which is applied to a non-AP multi-link device (non-AP MLD). The method includes: generating a request frame, the request frame being used to request roaming to a target AP MLD, the request frame including first indication information, the first indication information being used to determine the target AP MLD; and sending the request frame to the first AP MLD.

[0007] In an embodiment of the present application, the non-AP MLD sends a request frame to the first AP MLD, where the request frame is used to request roaming to the target AP MLD. This allows the first AP MLD to achieve uninterrupted transmission of the non-AP MLD during roaming to the target AP MLD through context transfer and other means, i.e., roaming with packet resumption is achieved, which can reduce packet loss and thus improve the user roaming experience.

[0008] In a possible implementation manner, the first indication information is used to indicate the target AP MLD, or the first indication information is a wildcard basic service set identifier (BSSID).

[0009] In this implementation, the first indication information is used to indicate the target AP MLD, so that the first AP MLD can know the AP MLD to roam the non-AP MLD to. The first indication information is a wildcard BSSID, so that the first AP MLD can decide which AP MLD to roam the non-AP MLD to.

[0010] In one possible implementation, the request frame further includes one or more second indication information, each second indication information being used to indicate a first link, where the first link is the link that the non-AP MLD requests the target AP MLD to establish. Alternatively, the request frame further includes second indication information, where the second indication information is used to indicate first links, where the first links include one or more links that the non-AP MLD requests the target AP MLD to establish.

[0011] In this implementation, the request frame further includes one or more pieces of second indication information, which may indicate the link that the non-AP MLD requests the target AP MLD to establish.

[0012] In a possible implementation, the request frame further includes third indication information and at least one of parameters used to establish one or more first links, and the third indication information is used to indicate a main link among the one or more first links.

[0013] In this implementation, the third indication information is used to indicate the primary link among the one or more first links, so that the target AP MLD knows the primary link that the non-AP MLD requests to establish. The request frame also includes parameters for establishing the one or more first links, which can more quickly determine the parameters for establishing the first links.

[0014] In a possible implementation manner, the request frame further includes fourth indication information, where the fourth indication information is used to indicate a link status of the first link after receiving the response frame.

[0015] In this implementation, the fourth indication information is used to indicate the link state of the first link after receiving the response frame, which can facilitate data transmission between the non-AP MLD, the current AP MLD, and the target AP MLD.

[0016] In a possible implementation, the link state includes enabled and disabled, or the link state includes awake and asleep states.

[0017] In a possible implementation, the request frame further includes timeout information, and the timeout information is used to feed back the determination of the valid time of the response frame corresponding to the request frame.

[0018] In this implementation, the request frame also includes timeout information, which is used to determine the validity period of the response frame corresponding to the feedback request frame; this can avoid long waiting times for non-AP MLD, which affects the roaming experience.

[0019] In a possible implementation manner, the request frame is a link reconfiguration request frame.

[0020] In this implementation, the advantage of multiplexing the link reconfiguration request frame is that it can simultaneously establish a link with the target AP MLD and trigger the first AP MLD to perform context transfer, thereby reducing the switching interaction to the target AP MLD and saving signaling overhead.

[0021] In one possible implementation, the method also includes: receiving a response frame from the first AP MLD, the response frame including fifth indication information, the fifth indication information being used to indicate a status code and / or a key update count value corresponding to the first link, the status code being used to indicate that the request to establish the first link is rejected or received, the key update count value being the number of times the key parameters of the basic service set (BSS) of the AP where the first link is located are currently updated, and when the BSS key parameters of the AP where the first link is located change, the key update count value increases by 1.

[0022] In this implementation, the fifth indication information is used to indicate the status code and / or key update count value corresponding to the first link, so that the non-AP MLD can know whether the request to establish the first link is received and / or whether the BSS key parameters of the AP where the first link is located need to be updated.

[0023] In a possible implementation manner, the response frame further includes sixth indication information, where the sixth indication information is used to indicate the target AP MLD.

[0024] In a possible implementation manner, the response frame is a link reconfiguration response frame.

[0025] In this implementation, link reconfiguration response frames are multiplexed, which can save signaling overhead.

[0026] In a second aspect, an embodiment of the present application provides a method for multi-link device communication, which is applied to a first AP MLD, and includes: receiving a request frame from a non-AP MLD, the request frame being used to request roaming to a target AP MLD, the request frame including first indication information, the first indication information being used to determine the target AP MLD; and performing a context transfer to the target AP MLD. The purpose of performing the context transfer is to roam the non-AP MLD to the target AP MLD. In other words, the context transfer is used to roam the non-AP MLD to the target AP MLD. Exemplarily, the context is used to configure the MLDMAC sublayer.

[0027] In this embodiment of the present application, context transfer is performed to a target AP MLD; roaming of a non-AP MLD to the target AP MLD is achieved. By performing context transfer to the target AP MLD, transmission of the non-AP MLD is uninterrupted during roaming, thereby achieving roaming with packet retransmission support, reducing packet loss and improving the user roaming experience.

[0028] In a possible implementation, the context includes Block Acknowledgement (BA) session-related parameters and / or security-related parameters.

[0029] In this implementation, if the context includes parameters related to the BA session, the context is transferred to the target AP MLD, which can reduce or avoid packet loss during roaming with the non-AP MLD, thereby improving the user roaming experience. If the context includes security-related parameters, the target AP MLD can perform encryption and decryption operations, improving data security.

[0030] In a possible implementation manner, the first indication information is used to indicate the target AP MLD, or the first indication information is a wildcard BSSID.

[0031] In a possible implementation, the request frame further includes one or more pieces of second indication information, each piece of the second indication information is used to indicate a first link, where the first link is the link that the non-AP MLD requests the target AP MLD to establish.

[0032] In a possible implementation, the request frame further includes third indication information and at least one of parameters used to establish one or more first links, and the third indication information is used to indicate a main link among the one or more first links.

[0033] In a possible implementation manner, the request frame further includes fourth indication information, where the fourth indication information is used to indicate a link status of the first link after receiving the response frame.

[0034] In a possible implementation, the link state includes enabled and disabled, or the link state includes awake and asleep states.

[0035] In a possible implementation, the request frame further includes timeout information, and the timeout information is used to feed back the determination of the valid time of the response frame corresponding to the request frame.

[0036] In a possible implementation manner, the request frame is a link reconfiguration request frame.

[0037] In one possible implementation, the method further includes: sending a response frame to the non-AP MLD, the response frame including fifth indication information, the fifth indication information being used to indicate a status code and / or a key update count value corresponding to the first link, the status code being used to indicate that the request to establish the first link is rejected or received, the key update count value being the number of times the basic service set BSS key parameters of the AP where the first link is located are currently updated, and when the BSS key parameters of the AP where the first link is located change, the key update count value increases by 1.

[0038] In this implementation, sending a response frame to the non-AP MLD may enable the non-AP MLD to learn the status code and / or the key update count value corresponding to the first link.

[0039] In a possible implementation manner, the response frame further includes sixth indication information, where the sixth indication information is used to indicate the target AP MLD.

[0040] In one possible implementation, the request frame further includes fourth indication information, where the fourth indication information is used to indicate a link status of a first link after receiving the response frame, where the first link is the link that the non-AP MLD requests the target AP MLD to establish. After sending the response frame to the non-AP MLD, the method further includes:

[0041] When the link state of the first link is disabled or in a dormant state, the remaining data packets in a transmission queue are sent to the non-AP MLD, the transmission queue including data packets to be sent to the non-AP MLD. When the last sequence number SN associated with the non-AP MLD on the first AP MLD is refreshed or times out, link deletion information is sent to the non-AP MLD, the link deletion information being used to instruct the non-AP MLD to delete the link of the first AP MLD. Sending the link deletion information to the non-AP MLD can be replaced by sending link disabling information to the non-AP MLD, the link disabling information being used to instruct the non-AP MLD to disable the link with the first AP MLD. Alternatively, sending the link deletion information to the non-AP MLD can be replaced by sending link dormancy information to the non-AP MLD, the link dormancy information being used to instruct the non-AP MLD to configure (switch) the link with the first AP MLD to a dormant state.

[0042] In this implementation, when the link state of the first link is disabled or in sleep state, the remaining data packets in the transmission queue are sent to the non-AP MLD, so that the non-AP MLD receives complete downlink data from the first AP MLD.

[0043] In a possible implementation manner, the response frame is a link reconfiguration response frame.

[0044] For possible implementations of the second aspect, reference can be made to various possible implementations of the first aspect.

[0045] For the technical effects brought about by various possible implementations of the second aspect, reference may be made to the introduction to the technical effects of various possible implementations of the first aspect.

[0046] In a third aspect, an embodiment of the present application provides a communication device, which has the function of implementing the behavior in the embodiment of the method of the first aspect above. The communication device can be a terminal device, or a component of a terminal device (such as a processor, a chip, or a chip system, etc.), or a logic module or software that can implement all or part of the functions of the terminal device. For example, the communication device is a second access point. The functions of the communication device can be implemented by hardware, or by hardware executing corresponding software, and the hardware or software includes one or more modules or units corresponding to the above functions. In one possible implementation, the communication device includes a transceiver module and a processing module, wherein: the processing module is used to generate a request frame, the request frame is used to request roaming to a target AP MLD, the request frame includes first indication information, and the first indication information is used to determine the target AP MLD; the transceiver module is used to send the request frame to the first AP MLD.

[0047] In one possible implementation, the transceiver module is also used to receive a response frame from the first AP MLD, and the response frame includes fifth indication information, and the fifth indication information is used to indicate the status code and / or key update count value corresponding to the first link, and the status code is used to indicate that the request to establish the first link is rejected or received, and the key update count value is the number of times the BSS key parameters of the AP where the first link is located are currently updated. When the BSS key parameters of the AP where the first link is located change, the key update count value increases by 1.

[0048] For possible implementations of the third aspect, reference can be made to various possible implementations of the first aspect.

[0049] For the technical effects brought about by various possible implementations of the third aspect, reference may be made to the introduction to the technical effects of various possible implementations of the first aspect.

[0050] In a fourth aspect, embodiments of the present application provide another communication device that has the functionality to implement the behaviors described in the method embodiment of the second aspect. The communication device may be a network device, a component of a network device (e.g., a processor, a chip, or a chip system), or a logic module or software that implements all or part of the functionality of the network device. For example, the communication device is a second access point. The functionality of the communication device may be implemented through hardware or through hardware executing corresponding software. The hardware or software includes one or more modules or units corresponding to the aforementioned functionality. In one possible implementation, the communication device includes a transceiver module and a processing module, wherein: the transceiver module is configured to receive a request frame from a non-AP MLD, the request frame being configured to request roaming to a target AP MLD, the request frame including first indication information used to determine the target AP MLD; and the processing module is configured to perform a context transfer to the target AP MLD. Exemplarily, the processing module is configured to perform a context transfer to the target AP MLD in response to the request frame.

[0051] In one possible implementation, the transceiver module is further used to send a response frame to the non-AP MLD, where the response frame includes fifth indication information, where the fifth indication information is used to indicate a status code and / or a key update count value corresponding to the first link, where the status code is used to indicate that the request to establish the first link is rejected or received, and where the key update count value is the number of times the BSS key parameters of the AP where the first link is located are currently updated. When the BSS key parameters of the AP where the first link is located change, the key update count value increases by 1.

[0052] In one possible implementation, the request frame further includes fourth indication information, where the fourth indication information is used to indicate a link state of a first link after receiving the response frame, where the first link is the link that the non-AP MLD requests the target AP MLD to establish. The transceiver module is further used to, when the link state of the first link is disabled or in a dormant state, send remaining data packets in a transmission queue to the non-AP MLD, where the transmission queue includes data packets to be sent to the non-AP MLD. When the last sequence number SN associated with the non-AP MLD on the first AP MLD is refreshed or times out, send link deletion information to the non-AP MLD, where the link deletion information is used to instruct the non-AP MLD to delete the link of the first AP MLD.

[0053] For possible implementations of the fourth aspect, reference may be made to various possible implementations of the second aspect.

[0054] For the technical effects brought about by various possible implementation methods of the fourth aspect, reference may be made to the introduction to the technical effects of various possible implementation methods of the second aspect.

[0055] In a fifth aspect, an embodiment of the present application provides another communication device, which includes one or more processors, and the one or more processors are used to process data and / or signaling so that the method of the first aspect or the second aspect mentioned above is implemented.

[0056] Optionally, the communication device further includes a memory storing a computer program or instruction. When the computer program or instruction is executed by the processor, the communication device performs the method of the first or second aspect described above. Exemplarily, the communication device may be a chip, the processor may be a processing unit in the chip, and the memory may be a random access memory or cache in the chip.

[0057] In the embodiment of the present application, during the execution of the above method, the process of sending information (or signal) in the above method can be understood as the process of outputting information based on the computer program or instructions of the processor. When outputting information, the processor outputs the information to the transceiver so that it can be transmitted by the transceiver. After being output by the processor, the information may undergo other processing before reaching the transceiver. Similarly, when the processor receives input information, the transceiver receives the information and inputs it into the processor. Furthermore, after the transceiver receives the information, the information may undergo other processing before being input into the processor.

[0058] For operations such as sending and / or receiving involved by the processor, unless otherwise specified, or unless they conflict with their actual functions or internal logic in the relevant description, they can be generally understood as computer programs or instruction outputs based on the processor.

[0059] During implementation, the processor may be a processor specifically configured to execute these methods, or may be a processor that executes computer programs or instructions in a memory to execute these methods, such as a general-purpose processor. For example, the processor may also be configured to execute a program stored in a memory. When the program is executed, the communication device performs the method described in the first aspect or any possible implementation of the first aspect.

[0060] In a possible implementation, the memory is located outside the communication device. In a possible implementation, the memory is located inside the communication device.

[0061] In a possible implementation, the processor and the memory may also be integrated into one device, that is, the processor and the memory may also be integrated together.

[0062] In a possible implementation, the communication device further includes a transceiver, and the transceiver is used to receive signals or send signals.

[0063] In a sixth aspect, the present application provides another communication device, which includes a processing circuit and an interface circuit, wherein the interface circuit is used to obtain data or output data; the processing circuit is used to execute the method of the first aspect or the second aspect mentioned above.

[0064] In a seventh aspect, the present application provides a computer-readable storage medium, which stores a computer program. The computer program includes program instructions, which, when executed, enable the computer to execute the method of the first or second aspect mentioned above.

[0065] In an eighth aspect, the present application provides a computer program product, which includes a computer program, and the computer program includes program instructions. When the program instructions are executed, the computer executes the method of the first aspect or the second aspect mentioned above.

[0066] In the ninth aspect, the present application provides a chip comprising a communication interface and a processor; the communication interface is used for transmitting and receiving signals of the chip; the processor is used for executing computer programs or instructions so that a communication device comprising the chip executes the method of the first or second aspect above.

[0067] In the tenth aspect, an embodiment of the present application provides a communication system, comprising the communication device described in the third aspect or any possible implementation of the third aspect, and the communication device described in the fourth aspect or any possible implementation of the fourth aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] FIG1 is a schematic diagram of a roaming scenario applicable to an embodiment of the present application;

[0069] FIG2 is an example of a structural diagram of a multi-link device provided in an embodiment of the present application;

[0070] FIG3 shows an example of a schematic structural diagram of a multi-link between multi-link devices provided in an embodiment of the present application;

[0071] FIG4 shows a schematic diagram of a format of a basic multilink element;

[0072] FIG5 is a schematic diagram showing a format of a reconfiguration multi-link element;

[0073] 6 is a schematic diagram of a connection method between a multi-link AP and a multi-link STA provided in an embodiment of the present application;

[0074] FIG7 is a schematic diagram of the architecture of a communication system provided in an embodiment of the present application;

[0075] FIG8 shows an example of a reconfiguration status list;

[0076] FIG9 shows an example of multicast key data;

[0077] FIG10 is a KDE format provided in an embodiment of the present application;

[0078] FIG11-1 is an MLO GTK KDE format provided in an embodiment of the present application;

[0079] FIG11-2 is an MLO IGTK KDE format provided in an embodiment of the present application;

[0080] FIG11-3 is an MLO BIGTK KDE format provided in an embodiment of the present application;

[0081] FIG12 is a format of an OCI element provided in an embodiment of the present application;

[0082] FIG13 is a flowchart of a BA session establishment provided in an embodiment of the present application;

[0083] FIG14 is a flow chart of a method for multi-link device communication provided by an embodiment of the present application;

[0084] FIG15 is an example of a frame structure of a request frame provided in an embodiment of the present application;

[0085] FIG16 is an example of a frame structure of another request frame provided in an embodiment of the present application;

[0086] FIG17 is an example of a frame structure of a response frame provided in an embodiment of the present application;

[0087] FIG18 is a flow chart of another method for multi-link device communication provided by an embodiment of the present application;

[0088] FIG19 is a flow chart of another method for multi-link device communication provided by an embodiment of the present application;

[0089] FIG20 is a schematic block diagram of a communication device 10 provided in an embodiment of the present application;

[0090] FIG21 is a schematic diagram of another communication device 20 provided in an embodiment of the present application;

[0091] FIG22 is a schematic diagram of a chip system 30 provided in an embodiment of the present application. DETAILED DESCRIPTION

[0092] The terms "first", "second", and various numerals (for example, "#1", "#2", etc.) in the specification, claims, and drawings of the present application are only used to distinguish different objects, rather than for describing a specific order. It will be appreciated that the various numerals involved in the embodiments of the present application are only for the convenience of describing the distinctions performed, and are not intended to limit the scope of the embodiments of the present application. The size of the sequence number of each process below does not mean the order of execution, and the execution order of each process should be determined by its function and inherent logic, and should not constitute any limitation to the implementation process of the embodiment of the present application. In addition, the terms "including" and "having" and any deformation thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or equipment, etc. comprising a series of steps or units, is not limited to the steps or units listed, but optionally also includes steps or units that are not listed, or optionally also includes other steps or units inherent to these processes, methods, products, or equipment, etc.

[0093] The "embodiment" mentioned in this document means that the specific features, structures or characteristics described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It can be understood explicitly and implicitly by those skilled in the art that the embodiments described herein can be combined with other embodiments. Some of the steps in the embodiments described herein can be used as an independent embodiment. In this application, the naming of messages (frames) is only used to distinguish different messages (frames) and should not be understood as a limitation. In other words, the name of any message or frame in this application can be replaced with other names, and this application is not limited.

[0094] The terms used in the following embodiments of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. As used in the specification of the present application and the appended claims, the singular expressions "one", "a kind of", "said", "above", "the" and "this" are intended to also include plural expressions, unless there is a clear contrary indication in the context. It should also be understood that the term "and / or" used in the present application refers to and includes any or all possible combinations of one or more listed items. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The term "multiple" used in the present application refers to two or more. In the textual description of the present application, the character " / " generally indicates that the objects associated before and after are in an "or" relationship.

[0095] It is understood that in each embodiment of the present application, "A corresponds to B" means that there is a corresponding relationship between A and B, and B can be determined according to A. However, it should also be understood that determining (or generating) B according to (or based on) A does not mean that B is determined (or generated) only according to (or based on) A, and B can also be determined (or generated) according to (or based on) A and / or other information.

[0096] It should be understood that, in this application, indication includes direct indication (also known as explicit indication) and implicit indication. Direct indication of information A refers to including information A; implicit indication of information A refers to indicating information A through the correspondence between information A and information B and the direct indication of information B. The correspondence between information A and information B can be predefined, pre-stored, pre-burned, or pre-configured.

[0097] It should be understood that, in this application, information C is used to determine information D, which includes both information D being determined solely based on information C and information D being determined based on information C and other information. Furthermore, information C can also be used to determine information D indirectly, for example, where information D is determined based on information E, and information E is determined based on information C.

[0098] In the embodiments of this application, words such as "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described in this application as "exemplary" or "for example" should not be construed as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0099] In addition, in each embodiment of the present application, "network element A sends information A to network element B" can be understood as the destination end of the information A or the intermediate network element in the transmission path between the destination end and the network element B, which may include directly or indirectly sending information to network element B. "Network element B receives information A from network element A" can be understood as the source end of the information A or the intermediate network element in the transmission path between the source end and the network element A, which may include directly or indirectly receiving information from network element A. The information may be processed as necessary between the source end and the destination end of the information transmission, such as format changes, but the destination end can understand the valid information from the source end. Similar expressions in this application can be understood similarly and will not be elaborated here.

[0100] In some of the drawings relating to the message (frame) structure in the embodiments of this application, examples of the lengths of fields in the message are provided. It should be understood that the lengths of the fields shown in the drawings of the embodiments of this application are only examples. In actual applications, the lengths of any field may vary. In the drawings relating to the message (frame) structure in the embodiments of this application, the positions of the fields are not limited.

[0101] In some of the drawings related to the message structure in the embodiments of this application, examples of the names of the fields in the message are given. It should be understood that the names of the fields shown in the drawings of the embodiments of this application are only examples, and in actual applications, the names of any field may change.

[0102] In the embodiments of the present application, the drawings involving the message structure are provided. Some of them show that the length of a field in the message is 0 or variable, indicating that the field is an optional field, that is, when the field is not included in the message, the length of the field is 0. If the length of the field is variable, it indicates that the length of the field is uncertain. In the actual design process, the specific length of the field can be indicated by other indication information, or the transceiver can negotiate the length of the field in advance, or the length of the field is predefined, or the receiving end can determine the length of the field based on other auxiliary information when receiving the message carrying the field, and parse the message. This application does not impose any restrictions on the method for determining the specific length of a field with a variable length. The length of the variable-length field involved in the message will not be repeated below.

[0103] The technical solutions provided in the embodiments of the present application can be applied to WLAN systems, such as Wi-Fi, etc. For example, the method provided in the embodiments of the present application can be applied to IEEE protocols, such as IEEE 802.11be / Wi-Fi 7 / EHT protocol, IEEE 802.11bn / UHR / Wi-Fi 8 protocol, IEEE Integrated mmWave / integrated millimeter wave / IMMW protocol, IEEE 802.15 / ultra-wideband (UWB) protocol, or IEEE 802.11bf / sensing / perception protocol; the present application can also support Spark Link / Nearlink standard protocol. The technical solutions provided in the embodiments of the present application can also be applied to wireless personal area networks (WPANs) based on UWB technology. For example, the method provided in the embodiments of the present application can be applied to IEEE802.15 series protocols, such as 802.15.4a protocol, 802.15.4z protocol or 802.15.4ab protocol, or a future generation of UWB WPAN protocols, etc., which are no longer listed one by one. The technical solutions provided in the embodiments of the present application can also be applied to the following communication systems, for example, the Internet of Things (IoT) system, the Vehicle to X (V2X), the Narrow Band Internet of Things (NB-IoT) system, devices in the Internet of Vehicles, IoT nodes and sensors in the Internet of Things (IoT), smart cameras in smart homes, smart remote controls, smart water and electricity meters, and sensors in smart cities, etc., or can also be applied to the Long Term Evolution (LTE) system, the fifth-generation (5G) communication system, and new communication systems that will emerge in the future development of communications.

[0104] WLAN systems can provide high-speed and low-latency transmission. As WLAN application scenarios continue to evolve, WLAN systems will be applied to more scenarios or industries, such as the Internet of Things industry, the Internet of Vehicles industry, the banking industry, corporate offices, sports stadiums and exhibition halls, concert halls, hotel rooms, dormitories, wards, classrooms, supermarkets, squares, streets, production workshops and warehouses, etc. Of course, devices supporting WLAN communication or perception (such as access points or stations) can be sensor nodes in smart cities (such as smart water meters, smart electricity meters, and smart air detection nodes), smart devices in smart homes (such as smart cameras, projectors, display screens, televisions, speakers, refrigerators, washing machines, etc.), nodes in the Internet of Things, entertainment terminals (such as wearable devices such as augmented reality (AR) and virtual reality (VR)), smart devices in smart offices (such as printers, projectors, speakers, and speakers, etc.), Internet of Vehicles (IoV) devices, infrastructure in daily life scenarios (such as vending machines, self-service navigation kiosks in supermarkets, self-service checkout devices, self-service ordering machines, etc.), and equipment in large sports and music venues. For example, access points and stations can be devices used in the IoV, IoT nodes and sensors in the Internet of Things, smart cameras, smart remote controls, smart water and electricity meters in smart homes, and sensors in smart cities.

[0105] Although the embodiments of the present application mainly take WLAN as an example, especially networks applied to the IEEE 802.11 series of standards, such as systems that support Wi-Fi 7, which can also be called extremely high-throughput (EHT), and systems that support Wi-Fi 8, which can also be called ultra-high reliability (UHR) or ultra-high reliability and throughput (UHRT). It will be readily understood by those skilled in the art that the various aspects involved in the embodiments of the present application can be extended to other networks that adopt various standards or protocols. For example, Bluetooth, high performance radio LAN (HIPERLAN) (a wireless standard similar to the IEEE 802.11 standard, mainly used in Europe) and wide area networks (WANs) or other networks now known or developed later.

[0106] The above-mentioned communication system applicable to the present application is only an example, and the communication system applicable to the present application is not limited to this. It is described uniformly here and will not be repeated below.

[0107] The method provided in the present application is mainly applied to a roaming scenario, which includes at least two access point (AP) multi-link devices (MLDs) and at least one non-access point (Non-AP) MLD. Figure 1 is a schematic diagram of a roaming scenario applicable to an embodiment of the present application. In the roaming scenario shown in Figure 1, when a non-AP MLD associated with AP MLD 1 moves from the coverage of AP MLD 1 to the coverage of AP MLD 2, the non-AP MLD establishes an association relationship with AP MLD 2, for example, STA1 of the non-AP MLD associates with AP1 of AP MLD 2 and STA2 of the non-AP MLD associates with AP2 of AP MLD 2. Figure 1 is only an example, and the number of non-AP MLDs and the number of AP MLDs in the roaming scenario are not limited.

[0108] A key technology of the Institute of Electrical and Electronics Engineers (IEEE) 802.11be (called Wi-Fi 7 by the Wi-Fi Alliance, also known as the extremely high throughput (EHT) standard) is multi-link technology. Accordingly, multi-link technology requires a multi-link device (MLD) to support it. MLD is a device that supports (has) multi-link simultaneous transmission. In the embodiments of the present application, a device that simultaneously supports multiple links and supports the IEEE 802.11 standard is referred to as a multi-link device. MLD can have the ability to establish multiple links simultaneously. For example, the multi-link device can be an AP MLD, or it can be a non-AP MLD, such as a station multi-link device (STA MLD). It should be noted that the names of the above-mentioned multi-link devices are only examples and do not constitute any limitation on the scope of protection of this application. For example, AP MLD can also be called multi-link AP, or with the development of communication technology, AP MLD can also have other names, which are not given examples here.

[0109] In the IEEE 802.11be (Wi-Fi 7) protocol, MLD can use multiple links simultaneously. In one possible implementation, the MLD has multiple radio frequency modules that can operate in different frequency bands. For example, the frequency bands in which the MLD operates can be all or part of 2.4 GHz, 5 GHz, 6 GHz, and high frequency 60 GHz. When the distance between the channels in which the two radio frequency modules in an MLD operate is large enough, the two radio frequency modules do not interfere with each other and can operate independently. If any two links support sending on one link while receiving on the other link, we call the two links supporting simultaneous transmitting and receiving (STR) capability. Otherwise, the two links are called non-STR. A multi-link device includes one or more affiliated stations (affiliated STAs). An affiliated STA is a logical station that can operate on one link. Among them, the affiliated station can be an access point (AP) or a non-access point station (non-AP STA). For ease of description, in this application, a multi-link device whose subordinate station is an AP may be referred to as a multi-link AP, a multi-link AP device, or an AP multi-link device (AP multi-link device), and a multi-link device whose subordinate station is a non-AP STA may be referred to as a multi-link STA, a multi-link STA device, or a STA multi-link device (STA multi-link device). For ease of description, "a multi-link device including subordinate STAs" is also briefly described as "a multi-link device including STAs" in this embodiment of the application.

[0110] It's important to note that a multi-link device includes multiple logical sites, each operating on a link. However, multiple logical sites can operate on the same link. The link identifier mentioned below represents a site operating on a link. That is, if there are more than one site on a link, more than one link identifier is required to represent them. The link mentioned below sometimes also refers to the site operating on that link.

[0111] During data transmission, multi-link APs and multi-link STAs can use link identifiers to identify a link or a station on a link. Before communication begins, the multi-link AP and STA can negotiate or communicate the mapping between link identifiers and links or stations on a link. This eliminates the need to transmit extensive signaling information to identify links or stations on a link; simply carrying the link identifier suffices, reducing signaling overhead and improving transmission efficiency.

[0112] In one example, when a multi-link AP device establishes a BSS, the management frame it sends, such as a beacon frame, carries an element including multiple link identification information fields, each of which can suggest a corresponding relationship between a link identifier and a station working on a link. Each link identification information field includes a link identifier and also includes: a media access control (MAC) address, an operation set, and a channel number, wherein one or more of the MAC address, the operation set, and the channel number can indicate a link. In another example, during the multi-link association process, the multi-link AP device and the multi-link station device negotiate multiple link identification information fields. In subsequent communications, the multi-link AP device or the multi-link station device will use the link identifier to represent a station in the multi-link device. The link identifier can also represent one or more attributes of the station's MAC address, the working operation set, and the channel number. The MAC address can also be replaced with the association identifier of the multi-link AP device after association.

[0113] If multiple stations work on a link, the link identifier (a numerical ID) not only represents the operation set and channel number of the link, but also includes the station identifier working on the link, such as the station's MAC address or AID.

[0114] Multi-link devices can implement wireless communications using the 802.11 family of protocols. For example, they can implement Extremely High Throughput (EHT) stations or 802.11be-based or 802.11be-compatible stations to communicate with other devices. These other devices may or may not be multi-link devices.

[0115] The non-AP MLD involved in this application can be a wireless communication chip, a wireless sensor or a wireless communication terminal. For example, a user terminal, a user device, an access device, a subscriber station, a subscriber unit, a mobile station, a user agent, and a user equipment that support Wi-Fi communication functions, wherein the user terminal can include various handheld devices with wireless communication functions, vehicle-mounted devices, wearable devices, Internet of Things (IoT) devices, computing devices or other processing devices connected to a wireless modem, as well as various forms of user equipment (UE), mobile station (MS), terminal, terminal equipment, portable communication devices, handheld devices, portable computing devices, entertainment devices, gaming devices or systems, global positioning system devices or any other suitable devices configured to communicate over a wireless medium. In addition, the non-AP MLD can support the 802.11be standard or the next generation of 802.11be, such as WLAN standards such as Wi-Fi 8. Non-AP MLD can also support multiple WLAN standards such as 802.11ax, 802.11ac, 802.11n, 802.11g, 802.11b, and 802.11a.

[0116] The AP MLD involved in the embodiments of the present application can be a device deployed in a wireless communication network to provide wireless communication functions to its associated non-APs. It is mainly deployed in homes, buildings, and campuses, with a typical coverage radius of tens to hundreds of meters. Of course, it can also be deployed outdoors. The AP MLD is equivalent to a bridge connecting wired and wireless networks. Its main function is to connect various wireless network clients together and then connect the wireless network to the Ethernet. Specifically, the AP MLD can be a communication device such as a base station, router, gateway, repeater, communication server, switch, or bridge with a Wi-Fi chip, wherein the base station can include various forms of macro base stations, micro base stations, relay stations, etc. In addition, the AP MLD can support 802.11be standards or the next generation of 802.11be, such as Wi-Fi 8 and other WLAN standards. The AP MLD can also support WLAN standards such as 802.11ax, 802.11ac, 802.11n, 802.11g, 802.11b, and 802.11a.

[0117] The MAC layer of MLD is divided into the MLD upper MAC sublayer and the MLD lower MAC sublayer. Each subsidiary station included in MLD has its own media access control (MAC) address. The MAC address of each subsidiary station can be called a low MAC address. MLD has an upper MAC address. The lower MAC address corresponds to the MLD lower MAC sublayer, and the upper MAC address corresponds to the MLD upper MAC sublayer. Figure 2 is an example of a structural schematic diagram of a multi-link device provided by an embodiment of the present application. As shown in Figure 2, the subsidiary stations of AP MLD include AP1 and AP2. The lower MAC address of AP1 (corresponding to MLD lower MAC sublayer 1) is MAC address #1, and the lower MAC address of AP2 (corresponding to MLD lower MAC sublayer 2) is MAC address #2. AP MLD also has an upper MAC address, called the MLD MAC address. The low MAC address of AP1 may be the MAC address of a link associated with (supported by) AP1, and the low MAC address of AP2 may be the MAC address of a link associated with AP2.

[0118] In order to facilitate understanding of the technical solutions of the embodiments of the present application, a brief description of the technologies that may be involved in the embodiments of the present application is first given.

[0119] 1) Multi-link establishment: AP MLD and non-AP MLD can establish a multi-link connection through signaling interaction on any link. Figure 3 shows an example of a structural schematic diagram of a multi-link between multi-link devices provided in an embodiment of the present application. As shown in Figure 3, AP MLD includes AP1 and AP2, AP1 includes AP1 physical layer (physical layer, PHY), AP1 low MAC (i.e., MLD low MAC sublayer) and MLD high MAC (i.e., MLD high MAC sublayer), AP2 includes AP2 PHY, AP2 low MAC and MLD high MAC, wherein AP1 and AP2 share MLD high MAC, non-AP MLD includes STA1 and STA2, STA1 includes STA1 PHY, STA1 low MAC and MLD high MAC, STA2 includes STA2 PHY, STA2 low MAC and MLD high MAC, wherein STA1 and STA2 share MLD high MAC, AP1 and STA1 are connected through link 1, and AP2 and STA2 are connected through link 2. FIG3 is only an example. The number of APs included in the AP MLD, the number of STAs included in the non-AP MLD, and the number of links between the AP MLD and the non-AP MLD are not limited.

[0120] For a non-AP MLD, it can establish associations with multiple links of the AP MLD simultaneously by performing a multi-link establishment operation on one of the links. In one possible implementation, during multi-link establishment, the non-AP MLD and the AP MLD can establish an association through an association process. Referring to Figure 3 , the multi-link establishment process may include: Step 1) The non-AP MLD sends an Association Request frame on Link 1. The Association Request frame carries STA-side information for Link 1 and STA-side information for Link 2. For example, the Association Request frame may carry a Multi-link Element field, which is used to carry information about the non-AP MLD and stations within the non-AP MLD. Step 2) The AP MLD sends an Association Response frame on Link 1. The Association Response frame carries AP-side information for Link 1 and AP-side information for Link 2, thereby establishing associations (or completing associations) between STA1 and STA2 of the non-AP MLD and AP1 and AP2 of the AP MLD, respectively. In the multi-link establishment process, the link that exchanges association request / response frames (eg, link 1) is called a transmitted link, and the corresponding other links (eg, link 2) are called non-transmitted links.

[0121] In order to carry non-AP MLD related information in the existing association request frame, the IEEE 802.11be protocol defines a Basic Multi-link Element (BME), which uses inheritance to carry MLD related information, similar to the Multi-BSS identifier (BSSID) element in the existing protocol. BSS is the abbreviation of Basic Service Set (BSS). In one possible implementation, the BME includes a Multi-Link Control (MLC) field, a Common Info (COMMON INFO) field, and a Link Info (LINK INFO) field, where the Common Info field carries common information for multiple stations in the MLD, as well as information about the MLD itself. The Link Info field carries information about stations on each link in the MLD, such as the Per-STA Profile shown in Figure 4. Exemplarily, a single STA configuration (PER-STA PROFILE) includes a subelement ID (SUB ELEMENT ID), a length (LENGTH), STA Control (STA CONTROL), STA Information (STA Info), and STA Configuration (STA PROFILE). Figure 4 shows a schematic diagram of the format of a BME. The meaning of each field in Figure 4 can be found in the existing protocol and will not be described in detail here. The multi-link control field carries the type of multi-link element (for example, there are currently defined variants such as Basic variant, Reconfiguration variant, and Probe Request variant), as well as the Presence Bitmap field, which indicates which fields do not appear. The inheritance method means that only when the content of the corresponding element of the corresponding link in the Per-STA Profile is different from the content of the corresponding element of the corresponding link in the frame body, it will be carried in the Per-STA Profile. If the content of the corresponding elements is the same, there is no need to repeat it in the Per-STA Profile.

[0122] Figure 5 shows a schematic diagram of the format of a reconfiguration multi-link element. As shown in Figure 5, the reconfiguration multi-link element includes a multi-link control field, a common information field, and a link information field. Exemplarily, the multi-link control field includes a type, a bitmap, and a reservation. Exemplarily, a single STA configuration (Per-STA Profile) includes a subelement ID, a length, a STA control, and a STA information field. Among them, the STA control field may include a link identifier (ID), a complete profile, a STA MAC address present, a removal timer present, an operation parameter present, and a reservation. The STA information may include at least one of the STA information length, the STA MAC address, the AP removal timer, and the operation parameters. The meaning of each field in FIG5 can be found in the existing protocol and will not be described in detail here.

[0123] 2) MLD MAC layer unicast data plane architecture: The MAC layer of MLD can be divided into the MLD upper MAC sublayer (MLD Upper MAC sublayer, which can be referred to as the upper MAC layer) and the MLD lower MAC sublayer (MLD lower MAC sublayer, which can be referred to as the lower MAC layer). Subordinate APs under the same AP MLD share one MLD upper MAC sublayer, and each subordinate AP has its own MLD lower MAC sublayer, as shown in Figure 6 below. Figure 6 is a schematic diagram of a connection method between a multi-link AP and a multi-link STA provided in an embodiment of the present application. The 802.11 standard focuses on the 802.11 PHY and MAC layer portions in multi-link devices, so Figure 6 only exemplarily shows the PHY and MAC layers.

[0124] As shown in Figure 6, a multi-link device (such as a multi-link AP and a multi-link STA) may include a PHY (PHY#1, PHY#2, and PHY#n as shown in Figure 6) and a MAC layer. The physical layer may be used to process physical layer signals, and the MAC layer may be used to process MAC layer signals. Furthermore, the MAC layer may be divided into a high-MAC layer (high-MAC as shown in Figure 6) and multiple low-MAC layers (low-MAC#1, low-MAC#2, through low-MAC#n as shown in Figure 6). As shown in Figure 6, the multiple APs included in a multi-link AP are independent of each other in the low-MAC layer and PHY, but share the high-MAC layer. The multiple STAs included in a multi-link STA are independent of each other in the low-MAC layer and PHY, but share the high-MAC layer. The high-MAC layer is connected to the multiple low-MAC layers, meaning that the high-MAC layer is shared by multiple links. Exemplarily, the high MAC layer includes the following functions: when the MLD sends data, the high MAC layer can implement one or more of the following functions: allocation of sequence numbers (SN) and packet numbers (PN) of MAC service data units (MSDUs), encryption of MAC protocol data units (MPDUs), mapping of traffic identifiers (TIDs) to links (TID-to-links), etc.; when the MLD sends data, the high MAC layer can implement one or more of the following functions: block confirmation scoreboard maintenance, duplicate detection, MPDU decryption, packet reordering, replay attack detection, etc.

[0125] In Figure 6, the PHY#1, lower MAC#1, and upper MAC layers in a multi-link AP can be considered AP#1, the PHY#2, lower MAC#2, and upper MAC layers can be considered AP#2, and so on. The PHY#n, lower MAC#n, and upper MAC layers can be considered AP#n, meaning that a multi-link AP can be understood as comprising n AP entities. A similar situation exists in a multi-link STA, where the upper MAC layer is also shared by multiple links. The PHY#1, lower MAC#1, and upper MAC layers can be considered STA#1, the PHY#2, lower MAC#2, and upper MAC layers can be considered STA#2, and so on. The PHY#n, lower MAC#n, and upper MAC layers can be considered STA#n, meaning that a multi-link STA can be understood as comprising n STA entities. As shown in Figure 6, PHY#1 of AP#1 in the multi-link AP and PHY#1 of STA#1 in the multi-link STA operate on a common channel, and AP#1 in the multi-link AP and STA#1 in the multi-link STA communicate through a link (link #1 as shown in Figure 6); PHY#2 of AP#2 in the multi-link AP and PHY#2 of STA#2 in the multi-link STA operate on another common channel, and AP#2 in the multi-link AP and STA#2 in the multi-link STA communicate through a link (link #2 as shown in Figure 6); PHY#n of AP#n in the multi-link AP and PHY#n of STA#n in the multi-link STA operate on another common channel, and AP#n in the multi-link AP and STA#n in the multi-link STA communicate through a link (link #n as shown in Figure 6).

[0126] Exemplarily, the high MAC layer or the low MAC layer can be implemented by a processor in a chip system of a multi-link device, or can be implemented by different software processing modules in a chip system, etc., which are not listed in the embodiments of the present application. It can be understood that Figure 6 can be understood as a division of functional modules of a multi-link device. The modules shown in Figure 6 can be implemented in the form of hardware or software functional modules. The PHY and MAC layers shown in Figure 6 can be understood as a division of logical functions. In actual implementation, there can be other division methods. The n shown in Figure 6 can be equal to 1, or n can be an integer greater than 1, etc.

[0127] For a multi-link device, in addition to having its own MAC address for each link, each multi-link device also has an MLD MAC address. Taking the architecture shown in FIG6 as an example, the high MAC layer can be uniquely identified by the MAC address corresponding to the MLD, and the low MAC layer can be uniquely identified by the MAC address corresponding to the link. For example, low MAC#1 and low MAC#2 can correspond to the MAC addresses of their respective links, respectively. For example, the multi-link device in the embodiments of the present application can be a single-antenna device or a multi-antenna device. For example, it can be a device with more than two antennas. The embodiments of the present application do not limit the number of antennas included in the multi-link device.

[0128] In one possible implementation, all links in the same MLD share a pairwise transient key (PTK), but each link has its own group temporal key (GTK), integrity group temporal key (IGTK), and beacon integrity group temporal key (BIGTK).

[0129] 3) Non-collocated AP MLD (Non-collocated AP MLD) or roaming AP MLD (RoamingAP MLD) architecture: Currently, IEEE 802.11be is discussing a new AP MLD architecture, called Non-collocated AP MLD. Non-collocated AP MLD can also be called logical AP MLD (logical AP MLD), and co-located AP MLD can also be called physical AP MLD (physical AP MLD). A possible deployment form of the non-collocated AP MLD architecture is that the MLD Upper MAC sublayer and MLD Lower MAC sublayer of AP MLD are not in the same device, and they communicate through wired, as shown in Figure 7 below. Figure 7 is an architectural diagram of a communication system provided in an embodiment of the present application. The architecture shown in Figure 7 includes a UHR system, an EHT system, and a system before EHT (such as called pre-EHT). It can be understood that the lines or dotted lines of different thicknesses shown in Figure 7 are intended to represent different transmission paths. Generally speaking, the interface between the upper layer (also referred to as the upper layer, such as the radio resource control (RRC) layer) and the MAC layer can be called a MAC service access point (SAP) (such as MAC SAP1 to MAC SAP7 indicated by the seven black dots in FIG7 ). The MAC address can uniquely identify the MAC SAP. It is understood that the representation method (such as the use of black dots) and the representation location (such as the location of the black dots) of the MAC SAP shown in FIG7 are merely examples and should not be construed as limiting the embodiments of the present application.

[0130] As an example, for Pre-EHT STA data, since it is associated with a subordinate AP, the data related to the Pre-EHT STA needs to be sent and received through the MAC SAP of the corresponding subordinate AP (MAC SAP1, MAC SAP3, MAC SAP4, MAC SAP6 as shown in Figure 7). As shown in Figure 7, for data from or to a pre-EHT STA, an AP can process the data through the non-MLD high MAC layer (MAC SAP1, MAC SAP3, MAC SAP4, MAC SAP6 as shown in Figure 7).

[0131] As another example, for EHT non-AP MLD data, since it is associated with a co-located AP MLD, all EHT non-AP MLD-related data must be sent and received through the MAC SAP of the corresponding co-located AP MLD (MAC SAP2 and MAC SAP5 as shown in Figure 7). As shown in Figure 7, for data from or to the EHT non-AP MLD, the co-located AP MLD can process the data through the AP MLD high MAC sublayer (MAC SAP2 and MAC SAP5 as shown in Figure 7) and then through the AP MLD low MAC sublayer. Each AP MLD lower MAC sublayer corresponds to a PHY. For example, for co-located AP MLD A, each AP MLD lower MAC sublayer corresponds sequentially to PHY 1 (also called link 1 or the PHY corresponding to link 1), ..., PHY N (also called link N or the PHY corresponding to link N). For co-located AP MLD B, each AP MLD lower MAC sublayer corresponds sequentially to PHY 1 (also called link 1 or the PHY corresponding to link 1), ..., PHY M (also called link M or the PHY corresponding to link M). A and B are used to distinguish different co-located AP MLDs, and M and N are both positive integers.

[0132] As another example, since data from a UHR non-AP MLD is associated with a non-co-located AP MLD, all data related to the UHR non-AP MLD must be sent and received via the MAC SAP (MAC SAP7, shown in Figure 7) of the corresponding non-co-located AP MLD. As shown in Figure 7, after processing data from or to the UHR non-AP MLD by the AP MLD higher MAC sublayer, the non-co-located AP MLD forwards the data via MAC SAP7 or forwards it to the corresponding co-located AP MLD. The co-located AP MLD then delivers the data to the modules related to TID and link mapping or link merging.

[0133] For example, the division of functions between the high MAC sublayer and the low MAC sublayer of a non-co-located AP MLD may depend on whether a certain traffic identifier (TID) is allowed to be mapped to links of different co-located AP MLDs. For example, when a certain traffic identifier (TID) is allowed to be mapped to links of different co-located AP MLDs, a block acknowledgment (BA) session for the TID needs to be maintained at the high MAC sublayer of the non-co-located AP MLD. The session may be refreshed based on BA information fed back by the corresponding co-located AP MLD.

[0134] It is understood that the AP MLD high MAC sublayer functional block can be placed in a co-located AP MLD, or in an access point controller, etc. The embodiments of the present application do not limit the configuration method of the high MAC sublayer of a non-co-located AP MLD. The AP MLD high MAC sublayer and the AP MLD low MAC sublayer can communicate via a network cable or other technology. For example, a non-co-located AP MLD can be understood as an AP MLD composed of multiple co-located AP MLDs. Alternatively, the non-co-located AP MLD can be understood as a device for centralized or unified management (or control) of multiple co-located AP MLDs.

[0135] Taking the relationship between the MAC address of an MLD and the MAC address of the link subordinate to the MLD as shown in Figure 2 , a similar relationship exists between non-co-located AP MLDs and co-located AP MLDs. For example, each non-co-located AP MLD has a non-co-located MLD MAC address (the upper MAC sublayer of the non-co-located AP MLD shown in Figure 7 ), the MLD MAC address of the co-located AP MLD subordinate to the non-co-located AP MLD, and the MAC address of the link subordinate to the co-located AP MLD. It can be understood that the non-co-located MLD MAC address can be understood as the MAC address of the AP MLD upper MAC sublayer shown in Figure 7 (for example, the MAC address of the AP MLD upper MAC sublayer can identify MAC SAP7). The n co-located AP MLDs subordinate to a non-co-located AP MLD can also be referred to as the non-co-located AP MLD including n co-located AP MLDs, or the non-co-located AP MLD corresponding to n co-located AP MLDs, etc.

[0136] It is understandable that the relationship between non-co-located AP MLD and co-located AP MLD may be described differently as the standard progresses. Therefore, the embodiment of the present application does not limit the description of the relationship between non-co-located AP MLD and co-located AP MLD.

[0137] In the non-co-located AP MLD architecture, a UHR non-AP MLD that needs to roam can be associated with a UHR non-collocated AP MLD, while an EHT non-AP MLD can only be associated with an AP MLD, and a Pre-EHT STA can only be associated with an affiliated AP. When a UHR non-AP MLD associated with a UHR non-collocated AP MLD moves from the coverage area of ​​one AP MLD to the coverage area of ​​another AP MLD, and both AP MLDs are affiliated with the UHR non-collocated AP MLD, data transmission can be uninterrupted during roaming by adding links and assigning multicast keys to the added links, without the need to update PTKs or reassociation.

[0138] It is worth noting that the non-collocated AP MLD architecture is sometimes also referred to as roaming AP MLD, meaning that the AP MLD architecture is proposed to improve the roaming performance of non-AP MLD.

[0139] However, there's currently no consensus on the specific implementation (deployment) of the non-co-located AP MLD architecture. Some believe that if the MLD Upper MAC sublayer and MLD Lower MAC sublayer of a non-co-located AP MLD are deployed in different locations, the communication latency between them will be significant, resulting in poor data transmission performance. Therefore, an alternative deployment of the non-co-located AP MLD architecture has been proposed: the MLD Upper MAC sublayer and MLD Lower MAC sublayer of a non-co-located AP MLD must be deployed on the same device. Furthermore, the MLD Upper MAC sublayer of a non-co-located AP MLD moves from one AP MLD to another as the non-AP MLD moves, i.e., by transferring the MLD Upper MAC sublayer via an upstream context. This context transfer can include MLD Upper MAC sublayer parameters and PTKSA information required for data transmission and reception. The advantage of this deployment method is that the MLD Upper MAC sublayer and the MLD Lower MAC sublayer are always located on the same device, and the communication latency between the MLD Upper MAC sublayer and the MLD Lower MAC sublayer is very low. For ease of description, we refer to the former deployment method as Deployment Method I and the latter as Deployment Method II.

[0140] 4) BSS Parameter Critical Update: To avoid clients (e.g., STAs) having to parse the Beacon frame content every time, the existing protocol defines a BSS Parameter Critical Update mechanism. Under this mechanism, the AP maintains a critical update counter and carries it in the Beacon frame. The STA stores the last critical update counter locally. If the local critical update counter differs from the critical update counter carried in the current Beacon frame, it is considered that the BSS parameters have changed, and the Beacon frame content will be further parsed. If the local critical update counter is the same as the critical update counter carried in the current Beacon frame, it is considered that the BSS parameters have not changed, and the Beacon frame content does not need to be parsed. The protocol defines which elements' content changes are defined as critical updates; when the content of these elements changes, the critical update value is incremented.

[0141] 5) Link Reconfiguration Request / Response Frames: The current IEEE 802.11be draft defines a multi-link reconfiguration operation that allows a non-AP MLD to add or remove one or more links while associated with the current AP MLD, without re-association. Multi-link reconfiguration does not require updating the PTK; instead, it only requires negotiation of per-link key information such as the GTK / IGTK / BIGTK for the newly added links. Specifically, multi-link reconfiguration is performed using the Link Reconfiguration Request / Response frame formats, as shown in Tables 1 and 2.

[0142] Table 1 Multilink reconfiguration request frame

[0143] The meaning of each field in Table 1 can be found in the existing protocol. When the Complete Profile subfield in the Reconfiguration Multilink element is set to 1, the Per-STA Profile carries all the fields and elements in the (Re)Association Request frame.

[0144] Table 2 Multilink reconfiguration response frame

[0145] In Table 2, Count is used to indicate the number of Reconfiguration Status Tuple fields in the Reconfiguration Status List; the Reconfiguration Status List is used to indicate the status code of the corresponding link, and its format is shown in Figure 8 below; the Multicast Key Data field is used to carry multicast key data, and its format is shown in Figure 9 below. Figure 8 shows an example of a Reconfiguration Status List. As shown in Figure 8, the Reconfiguration Status List includes multiple Reconfiguration Status Tuple fields, each of which includes a link identity (ID) and a status code, and each Reconfiguration Status Tuple field indicates the status of a link.

[0146] Figure 9 shows an example of multicast key data. As shown in Figure 9, the multicast key data includes a multicast data length (Key Data Length) and a key data (Key Data) subfield, and the multicast data length is used to indicate the length of the key data. The meaning of each field in Table 2 can be referred to the existing protocol. The Key Data subfield contains one or more multi-link operation (MLO) key data encapsulation (KDE) corresponding to the multicast key of the added link. Each MLO KDE is encapsulated using the KDE format shown in Figure 11. Figure 10 is a KDE format provided in an embodiment of the present application. For each added link, an MLO GTK KDE is included as defined in Figure 11-1 (MLO GTK KDE format), an MLO IGTK KDE is included as defined in Figure 11-2 (MLO IGTK KDE format), and an MLO BIGTK KDE is included as defined in Figure 11-3 (MLO BIGTK KDE)). Figure 11-1 is an MLO GTK KDE format provided in an embodiment of the present application. Figure 11-2 is an MLO IGTK KDE format provided in an embodiment of the present application. Figure 11-3 is an MLO BIGTK KDE format provided in an embodiment of the present application. Refer to Figure 10. When the Data type is MLO GTK KDE only, the Data field is shown in Figure 11-1. Refer to Figure 10. When the Data type is MLO IGTK KDE only, the Data field is shown in Figure 11-2.Refer to Figure 10. When the Data type is only MLO BIGTK KDE, the Data field is as shown in Figure 11-3.

[0147] The Operating Channel Information (OCI) element is used to indicate operating channel information, and its format is shown in Figure 12. Figure 12 shows the format of an OCI element provided in an embodiment of the present application.

[0148] 6) Block ACK session establishment: In a multi-link scenario, a block ACK session must be established before using multi-link aggregation transmission. The 802.11n protocol defines a BA mechanism, which improves channel efficiency by aggregating multiple "acknowledgments" into one frame. The BA mechanism is initiated by exchanging add block acknowledgment (addBA, ADDBA) request frames and ADDBA response frames. Specifically, the BA session establishment process is shown in Figure 13 below. Figure 13 is a BA session establishment flow chart provided in an embodiment of the present application. Referring to Figure 13, the BA session establishment process includes: the data sender (originator) (referred to as "sender") sends an ADDBARequest frame to the data receiver (recipient) (referred to as "receiver"), and the receiver replies with an ADDBAResponse frame to the sender. Through the above process, the BA mechanism (or "BA session") between the sender and the receiver is successfully established. Next, the transmitter sends multiple media access control layer protocol data units (MAC protocol data units, MPDUs) to the receiver. The multiple MPDUs sent by the transmitter to the receiver are aggregated into an aggregated media access control layer protocol data unit (A-MPDU). The transmitter sends a BA request (BAR) frame to the receiver. The receiver responds with a BA frame to the transmitter, confirming the receipt of all MPDUs in the A-MPDU sent by the transmitter. The initiator or responder can send a DELBA to terminate the block acknowledgement session for the corresponding TID.

[0149] Currently, there are two types of BA mechanisms: stateful BA and partial stateful BA. The stateful BA mechanism requires maintaining the scoreboard state throughout the entire BA session. Therefore, the receiving end must maintain the state of all active BA sessions, which places a heavy burden on the receiving end. The partial stateful BA mechanism only needs to store the state of the most recently active BA session in a cache. This ensures that the memory used to store BA state can be reused across different BA sessions and is backward compatible with the stateful BA mechanism.

[0150] A Block Ack session established between two stations has a specific traffic identifier (TID) and is used only for unidirectional data transmission, from the initiator to the responder. For example, for downlink data transmission, a BA session can only be initiated by the AP. For uplink data transmission, a BA session can only be initiated by the STA. Specifically, the initiator establishes a BA session for a specific TID by exchanging ADDBA Request / Response frames with the STA. The initiator or responder can terminate the Block Ack session for the corresponding TID by sending a DELBA.

[0151] The block confirmation session on the sending side includes one or more of the following parameters:

[0152] TID;

[0153] The SN (sequence number) assigned to each MSDU, block confirmation policy, whether MSDU aggregation is allowed, whether fragmentation is allowed, and whether HE fragmentation operation is supported;

[0154] Send the buffer's WinStart_O (window starting position), WinSize_O (window size);

[0155] The transmission success status and retransmission count of each MPDU in the window.

[0156] The receiving end's block confirmation session includes one or more of the following parameters:

[0157] TID;

[0158] Block confirmation policy, whether MSDU aggregation is allowed, whether fragmentation is allowed, and whether HE fragmentation operation is supported;

[0159] The receiving end scoreboard bitmap, as well as WinStart_R (window starting position), WinSize_R (window size), where the scoreboard bitmap is used to record which MSDUs are received successfully;

[0160] The receive reordering buffer's WinStart_B (window starting position) and WinSize_B (window size) are used to buffer received MSDUs. The MAC layer must deliver received MSDUs to the LLC layer in order. If a packet is not received successfully, subsequent MSDUs cannot be delivered to the LLC layer, even if they are received successfully.

[0161] For a certain TID, both the sender and the receiver can send DELBA to delete the block session.

[0162] Figure 13 shows the existing ADDBA Request / Response frame structure. The functions of the fields in Figure 13 can be found in existing protocols. The Frame Body of the ADDBA Request frame includes the fields shown in Table 3. The Frame Body of the ADDBA Response frame includes the fields shown in Table 4.

[0163] Table 3

[0164] Table 4

[0165] In order to achieve roaming of multi-link devices, the present application provides a solution for achieving multi-link device roaming by performing context transfer operations between different AP MLDs. The solution provided by the present application is applicable to deployment form II of the Roaming AP MLD (i.e., non-collocated AP MLD) architecture. In other words, when the Roaming AP MLD (i.e., non-collocated AP MLD) architecture is deployment form II, the solution of the present application can achieve roaming of multi-link devices. The general process of the solution provided by the present application is shown in Figure 14 below. Figure 14 is a flow chart of a method for multi-link device communication provided by an embodiment of the present application. As shown in Figure 14, the Non-AP MLD triggers roaming from the current AP MLD (i.e., the AP MLD currently associated with the Non-AP MLD) to the target AP MLD by sending a roaming request (Roaming Request) frame, which optionally includes the current AP MLD transferring the Context to the target AP MLD. After the context is transferred, the current AP MLD or the target AP MLD returns a roaming response Roaming Response frame to the Non-AP MLD. As shown in Figure 14, the method includes:

[0166] 1401. Non-AP MLD generates a request frame.

[0167] The request frame is used to request roaming to the target AP MLD.

[0168] In one possible implementation, the request frame is used to trigger roaming from the first AP MLD to the target AP MLD. The request frame can be considered a roaming request. In other words, the request frame is used to trigger the first AP MLD to roam the non-AP MLD to the target AP MLD.

[0169] In one possible implementation, the request frame is used to trigger the first AP MLD to transfer the context to the target AP MLD, thereby achieving roaming of the non-AP MLD to the target AP MLD. The request frame can be regarded as a roaming context transfer request. The above context is used to configure the MLD upper MAC sublayer, such as the MLD upper MAC sublayer of the target AP MLD. The above uplink text may include one or more of the following information: parameters of the MLD Upper MAC sublayer required for data transmission and reception, PTK, or PN. Exemplarily, the above uplink text may include at least one of BA session-related parameters and security-related parameters. BA session-related parameters (also called BA session context) are parameters of the MLD Upper MAC sublayer required for data transmission and reception, such as SN (sequence number), security-related parameters (also called security context), such as one or more of the information related to encryption and decryption such as PTKSA, and for example, PN (packet number). In one possible implementation, the context further includes one or more link indication information, where the link indication information is used to indicate a first link, where the first link includes the link that the non-AP MLD requests the target AP MLD to establish. The uplink context transfer step in this embodiment of the present invention is optional.

[0170] 1402. The Non-AP MLD sends a request frame to the first AP MLD.

[0171] Accordingly, the first AP MLD receives a request frame from the non-AP MLD. The first AP MLD is the AP MLD with which the non-AP MLD is currently associated. In other words, the first AP MLD currently has at least one link with the non-AP MLD. Alternatively, the non-AP MLD is associated with one or more links of the first AP MLD. The request frame may include first indication information, which is used to determine the target AP MLD.

[0172] In one possible implementation, the first indication information is used to indicate the target AP MLD. For example, the first indication information includes the MLD MAC address or MLD ID (i.e., the ID of the target AP MLD) of the target AP MLD. The first indication information may also include other information used to uniquely identify the target AP MLD, which is not limited here.

[0173] In one possible implementation, the first indication information includes a Wildcard MLD MAC Address field or a Wildcard BSSID. In this case, the non-AP MLD is not clear about which AP MLD to roam to, or in other words, the target AP MLD for roaming is determined by the first AP MLD. Exemplarily, the Wildcard MLD MAC Address field includes a broadcast address or a Wildcard BSSID, for example, the field is set to all 1s. The broadcast address or Wildcard BSSID is used to indicate that the non-AP MLD is not clear about which AP MLD to roam to. The embodiment of the present application does not limit the broadcast address or Wildcard BSSID. Exemplarily, the Wildcard BSSID is a special value specified by the protocol, such as all 0s or all 1s, which indicates that the first AP MLD determines to which AP MLD the non-AP MLD roams, that is, the first AP MLD determines the target AP MLD for the non-AP MLD to roam. The embodiment of the present application does not limit the special value.

[0174] In one possible implementation, the first indication information indicates an AP MLD set (including multiple AP MLDs), and the first indication information is used to instruct the first AP MLD to determine the selection of an AP MLD from the AP MLD set as the target AP MLD to which the non-AP MLD roams. That is, when the first indication information indicates an AP MLD set (including multiple AP MLDs), the first indication information implicitly indicates that the non-AP MLD is unclear about the AP MLD to roam to. In this case, the first AP MLD can determine the AP MLD in the AP MLD set to roam to. Exemplarily, the first indication information includes multiple AP MLDs, i.e., an AP MLD set. Exemplarily, the first indication information includes an index, and the index is associated with an AP MLD set.

[0175] In one possible implementation, the request frame further includes one or more second indication information, each second indication information being used to indicate a first link, where the first link is a link that the non-AP MLD requests the target AP MLD to establish. Exemplarily, each second indication information includes the link ID of a first link. The links that the non-AP MLD requests the target AP MLD to establish may include one or more first links, with different first links associated with different sites. In other words, the request frame further includes second indication information, where the second indication information is used to indicate first links, where the first links include one or more links that the non-AP MLD requests the target AP MLD to establish. Exemplarily, the second indication information includes an identifier of the first link, i.e., an identifier of the one or more links that the non-AP MLD requests the target AP MLD to establish. Optionally, the request frame further includes third indication information, where the third indication information is used to indicate a primary link among the first links. In other words, the third indication information is used to indicate a primary link among the one or more first links. Exemplarily, the request frame further includes a primary link indication field corresponding to each link in the first link, where the primary link indication field corresponding to each link is used to indicate whether the link is a primary link. Optionally, the request frame further includes information parameters for establishing the first link.

[0176] In one possible implementation, the request frame further includes fourth indication information, and the fourth indication information is used to indicate the link status of the first link after the non-AP MLD receives the response frame. Alternatively, the fourth indication information is used to indicate the link status of the first link after the first AP MLD and the target AP MLD complete context transfer. Alternatively, the fourth indication information is used to indicate the link status of the first link after the first AP MLD or the target AP MLD replies to the response frame. Exemplarily, each link ID in the first link is followed by an enable / disable status indication. An enable status indication after a link ID indicates that the link corresponding to the link ID is enabled after the non-AP MLD receives the response frame, or in other words, indicates that the link corresponding to the link ID is an enable link after the non-AP MLD receives the response frame. Alternatively, an enable status indication after a link ID indicates that the link corresponding to the link ID is in an enabled state after the non-AP MLD receives the response frame. A disable status indication following a link ID indicates that the link corresponding to the link ID is disabled after the non-AP MLD receives a response frame, or in other words, indicates that the link corresponding to the link ID is a disable link after the non-AP MLD receives a response frame. Alternatively, a disable status indication following a link ID indicates that the link corresponding to the link ID is in a disabled state after the non-AP MLD receives a response frame. Alternatively, a delete status indication following a link ID (e.g., a link between a first AP MLD and a non-AP MLD) indicates that the link corresponding to the link ID is deleted after the first AP MLD responds to the response frame. For example, each link ID in the first link is followed by an awake / doze status indication. An awake status indication following a link ID indicates that the link corresponding to the link ID is in an awake state after the non-AP MLD receives a response frame. A doze status indication following a link ID indicates that the link corresponding to the link ID is in a doze state after the non-AP MLD receives a response frame.

[0177] Optionally, the request frame further includes fourth indication information, and the fourth indication information is used to indicate the link status of the second link after the first AP MLD replies to the response frame. Alternatively, the fourth indication information is used to indicate the link status of the second link after the first AP MLD and the target AP MLD complete the context transfer. The second link includes the link between the first AP MLD and the non-AP MLD. Exemplarily, each link ID in the second link and / or the first link is followed by an enable / disable status indication. An enable status indication after the link ID indicates that the link corresponding to the link ID is enabled after the first AP MLD replies to the response frame, or in other words, indicates that the link corresponding to the link ID is an enable link in the first AP MLD reply response frame. A disable status indication after the link ID indicates that the link corresponding to the link ID is disabled after the first AP MLD replies to the response frame. Of course, the fourth indication information may not indicate the link status of the second link after the first AP MLD replies to the response frame, but may infer the link status of the second link based on the link status of the first link. For example, if the first link is in the disabled state, then the second link between the non-AP MLD station operating on the first link (for the target AP MLD) and the AP of the first AP MLD is in the enabled state. For another example, if the first link is in the enabled state, then the second link between the non-AP MLD station operating on the first link (for the target AP MLD) and the AP of the first AP MLD is in the disabled state. The enable / disable in the link status may also be replaced by awake / doze.

[0178] When the request frame also includes fourth indication information, the primary link among the first links can be indicated as follows: if the first link includes only one link and an enable status indication, the link is the primary link. When the request frame also includes fourth indication information, the primary link among the first links can also be indicated as follows: if the first link includes multiple links and an enable status indication, the request frame also includes a primary link indication field corresponding to each enable link in the first link, indicating whether the enable link is the primary link. In one possible implementation, the Non-AP MLD requires that the primary link it requests the target AP MLD to establish must be accepted; otherwise, all links established by the target AP MLD are rejected. This prevents the target AP MLD from establishing a link that does not meet the Non-AP MLD requirements. In this implementation, by indicating at least one of the link status of the second link and the link status of the first link after the first AP MLD replies to the response frame, data transmission between the Non-AP MLD, the current AP MLD, and the target AP MLD can be facilitated.

[0179] In one possible implementation, the request frame also includes timeout information, which is used to determine the validity period of a response frame corresponding to the request frame. Exemplarily, the timeout information is used by the first AP MLD or the target AP MLD to determine the validity period of a response frame corresponding to the request frame. The timeout information may be a timeout value. Exemplarily, the timeout information includes a time length (duration), which indicates that the first AP MLD or the target AP MLD must return a response frame within the time length after receiving the request frame, otherwise the roaming request or context transfer request is considered failed. Exemplarily, the timeout information indicates an absolute time before which the first AP MLD or the target AP MLD must return a response frame; if no response frame is returned before the time, the roaming request or context transfer request is considered failed. In this implementation, the request frame also includes timeout information, which is used to determine the validity period of a response frame corresponding to the request frame. This can prevent the non-AP MLD from having to wait for a long time, which could affect the roaming experience.

[0180] In one possible implementation, the request frame is a management frame, such as a link reconfiguration request frame. In other words, the request frame can reuse the link reconfiguration request frame. In one possible implementation, a new element is added to the link reconfiguration request frame (Link Reconfiguration Request) to carry one or more of the above-mentioned first indication information, second indication information, third indication information, fourth indication information, or timeout information. When the first AP MLD receives the link reconfiguration request frame, in addition to performing the link reconfiguration operation, it also performs context transfer. In this implementation, the advantage of multiplexing the link reconfiguration request frame is that it can trigger the first AP MLD to perform context transfer while establishing a link with the target AP MLD, thereby reducing the switching to the target AP MLD interaction and saving signaling overhead.

[0181] Figure 15 is an example of the frame structure of a request frame provided in an embodiment of the present application. As shown in Figure 15, the request frame includes: a Category field, an MLD MAC address, link information (Link Info) (optional), and a timeout value (optional). The Category field in the embodiment of the present application can be used to indicate the type of frame / message, that is, to distinguish different types of action frames. The type indicated by the Category field in Figure 15 corresponds to a request frame for requesting roaming to the target AP MLD, such as a request frame for triggering uplink transfer. The MLD MAC Address field is used to indicate the MLD MAC address or MLD ID of the target AP MLD. The MLD MAC Address field is an example of the first indication information. Referring to Figure 15, the link information field includes a second field and optionally includes a first field. The first field is used to indicate the link status of the second link after the first AP MLD replies to the response frame. Referring to Figure 15 , the first field includes a link ID (Link ID) and a link status indication (e.g., enable / disable). Each link ID is the ID of a link in the second link, and x1 and y1 are integers greater than or equal to 0. If a link ID is associated with an enable status indication, the link corresponding to that link ID is not disabled after the first AP MLD reply response frame; if a link ID is associated with a disable status indication, the link corresponding to that link ID is disabled after the first AP MLD reply response frame. The second field is used to indicate the first link, the link status of the first link after the first AP MLD reply response frame, and the primary link in the first link. The second field may include a link ID (Link ID), a link status indication (e.g., enable / disable), and a primary link indication (optional). Referring to Figure 15 , the second field includes a link ID (Link ID), a link status indication, and a primary link indication. Each link ID is the ID of a link in the first link, and the primary link indication associated with each link ID indicates whether the link is the primary link. x2 and y2 are integers greater than 0. For example, when the value of the main link indication associated with a link ID is 1, the link corresponding to the link ID is the main link. The above-mentioned second indication information includes each link ID in the second field, that is, the link ID of the first link. In other words, each link ID in the second field is an example of the above-mentioned second indication information. The above-mentioned third indication information includes the main link indication associated with each link ID in the second field. In other words, the main link indication associated with each link ID in the second field is an example of the above-mentioned third indication information. The above-mentioned fourth indication information includes the link status indication associated with each link ID in the second field, and optionally, also includes the link status indication associated with each link ID in the first field.In other words, at least one of the link status indications associated with each link ID in the first field and the link status indications associated with each link ID in the second field is an example of the fourth indication information. The timeout value is the timeout information. The timeout value represents a time length or an absolute time.

[0182] Figure 16 is an example of the frame structure of another request frame provided in an embodiment of the present application. As shown in Figure 16, the request frame includes: a Category field, a wildcard MLD MAC address / Wildcard BSSID, link information (Link Info) (optional), and a timeout value (optional). The wildcard MLD MAC Address or Wildcard BSSID is used to indicate that the non-AP MLD does not know which AP MLD to roam to. In other words, the wildcard MLD MAC Address or Wildcard BSSID is used to indicate any target AP MLD, or the target AP MLD for context transfer is determined by the above-mentioned first AP MLD. The functions of the other fields in Figure 16 can be found in the description of each field in Figure 15.

[0183] 1403. The first AP MLD receives the request frame and transfers the context to the target AP MLD.

[0184] The request frame is used to request roaming to a target AP MLD. The first indication information in the request frame is used to determine the target AP MLD.

[0185] In one possible implementation, the request frame is used to trigger the first AP MLD to transfer the context to the target AP MLD, and the first indication information is used to indicate the target AP MLD; the first AP MLD can determine the target AP MLD for context transfer based on the request frame and transfer the context to the target AP MLD.

[0186] In one possible implementation, the request frame includes first indication information, where the first indication information indicates an AP MLD set (including multiple AP MLDs). The first indication information is used to instruct the first AP MLD to determine which AP MLD to select from the AP MLD set as the target AP MLD for context transfer. Based on the request frame, the first AP MLD selects an AP MLD from the AP MLD set as the target AP MLD for context transfer and performs context transfer to the target AP MLD. The implementation of the first AP MLD selecting an AP MLD from the AP MLD set as the target AP MLD for context transfer based on the request frame is not limited. Exemplarily, the first AP MLD first estimates the distance between each AP MLD in the AP MLD set and a non-AP MLD; then, the first AP MLD selects the AP MLD in the AP MLD set that is closest to the non-AP MLD as the target AP MLD for context transfer. Exemplarily, the first AP MLD selects the AP MLD in the AP MLD set with the highest signal strength as the target AP MLD for context transfer. Exemplarily, the first AP MLD selects an AP MLD with the lightest load in the AP MLD set as the target AP MLD for context transfer.

[0187] In one possible implementation, the request frame includes first indication information, which includes a Wildcard MLD MAC Address field or a Wildcard BSSID, indicating that no target AP MLD is specified, or indicating that the first AP MLD determines the target AP MLD for context transfer. Based on the request frame, the first AP MLD selects an AP MLD as the target AP MLD for context transfer and performs context transfer to the target AP MLD. The manner in which the first AP MLD selects the target AP MLD for context transfer is not limited. Exemplarily, the first AP MLD selects the AP MLD closest to the non-AP MLD from among nearby AP MLDs as the target AP MLD for context transfer. Exemplarily, the first AP MLD selects the AP MLD closest to the non-AP MLD as the target AP MLD for context transfer. Exemplarily, the first AP MLD selects the AP MLD with the lightest load from among nearby AP MLDs as the target AP MLD for context transfer.

[0188] The context transfer performed by the first AP MLD to the target AP MLD may include: the first AP MLD transmitting at least one of a BA session context and a security context to the target AP MLD. In one possible implementation, when a non-AP MLD roams from a current AP MLD to a target AP MLD, the BA session context may be transferred from the current AP MLD to the target AP MLD to prevent packet loss. Context transfer (including the BA session context) to the target AP MLD prevents packet loss, thereby ensuring that transmission of the non-AP MLD is not interrupted during roaming to the target AP MLD. This implements a roaming mechanism that supports packet retransmission. In a multi-link scenario, a block acknowledgement session must be established before using multi-link aggregation transmission. The first AP MLD transmits the BA session context to the target AP MLD. This eliminates the need to perform a BA session establishment process before using multi-link aggregation transmission between the non-AP MLD and the target AP MLD, thereby reducing the delay in the non-AP MLD roaming to the target AP MLD. For example, for downlink transmission of TID#n, the first AP MLD can transfer the BA session context of the sender of TID#n (i.e., the AP MLD end) to the target AP MLD. The BA session context includes at least one of the following items: SN Counter, WinStart_O and WinSize_O of the send buffer; the sending success status and number of retransmissions of each MSDU / MPDU in the send window; whether A-MSDU is enabled; whether the block confirmation policy is immediate block confirmation or delayed block confirmation; the timeout value of the block session; whether fragmentation is allowed; and whether HE (High Efficiency) fragmentation operation is supported. For example, for uplink transmission of TID#n, the first AP MLD can transfer the BA session context of the receiver (i.e., the AP MLD) of TID#n to the target AP MLD. The BA session context includes at least one of the following: a receiver scoreboard and its corresponding WinStart_R (window start position) and WinSize_R (window size). The scoreboard is used to record which MSDUs are successfully received; WinStart_B (window start position) and WinSize_B (window size, i.e., buffer size) of the receive reordering buffer; the receive reordering buffer is used to buffer received MSDUs, as the MAC layer must deliver received MSDUs to the LLC layer in order. If a packet is not received successfully, then other MSDUs following it cannot be delivered to the LLC layer even if they are received successfully; whether A-MSDU is enabled; whether the block acknowledgment policy is immediate or delayed; the block session timeout value; whether fragmentation is allowed; and whether HE fragmentation is supported.The security context may include one or more of the following: PTK, PN counter, or replay counter.

[0189] In one possible implementation, the target AP MLD configures the MLD high MAC sublayer for data transmission between itself and the non-AP MLD based on the context from the first AP MLD, such as at least one of the BA session context and the security context. The configured MLD high MAC sublayer parameters can be the same as those used by the first AP MLD for data transmission between itself and the non-AP MLD. This implementation is equivalent to transferring the MLD high MAC sublayer from the first AP MLD to the target AP MLD, thereby enabling non-AP MLD roaming.

[0190] In one possible implementation, the target AP MLD establishes one or more link associations with the non-AP MLD based on the context from the first AP MLD, such as at least one of the BA session context and the security context, and the second indication information, and uses multi-link aggregation transmission to transmit with the non-AP MLD.

[0191] 1404. The first AP MLD or the target AP MLD sends a response frame to the non-AP MLD.

[0192] Accordingly, the non-AP MLD receives a response frame from the first AP MLD or the target AP MLD. In one possible implementation, after completing context transfer to the target AP MLD (i.e., sending the context to the target AP MLD), the first AP MLD sends a response frame to the non-AP MLD. In another possible implementation, after receiving the context from the first AP MLD, the target AP MLD sends a response frame to the non-AP MLD. The two dashed boxes in Figure 14 illustrate two possible solutions for step 1404.

[0193] The response frame includes the sixth indication information (optional) and the fifth indication information. The sixth indication information is used to indicate the target AP MLD. In one possible implementation, the first indication information in the request frame is used to indicate the target AP MLD for context transfer, and the response frame may or may not include the sixth indication information. In one possible implementation, the first indication information in the request frame is used to indicate roaming from the first AP MLD to the target AP MLD, for example, including the first AP MLD transferring the context to the target AP MLD. The response frame includes the sixth indication information and the fifth indication information. The fifth indication information is used to indicate the status code and / or critical update counter corresponding to the first link. The status code indicates whether the request to establish the first link was rejected or accepted. The critical update counter is the current number of updates to the BSS critical parameters of the AP to which the first link belongs. When the BSS critical parameters of the AP to which the first link belongs change, the BSS critical parameter update counter is incremented by 1 or another value. The receiving end (a station of the non-AP MLD) maintains or retains the BSS critical parameter update counter (which may be referred to as the critical update counter). Wait until the next time any AP receives MLD to broadcast the BSS key parameter update count value of the AP where the first link is located, and compare it with the BSS key parameter update count value received or maintained last time. If they are the same, it means that the BSS key parameters of the AP where the first link is located have not changed, otherwise the BSS key parameters of the AP where the first link is located have changed. Exemplarily, the fifth indication information also includes the link ID of each link in the first link, and the status code and key update count value (or key update counter) corresponding to each link. The status code corresponding to each link is used to indicate whether the request to establish the link is rejected or accepted. The key update count value corresponding to each link indicates whether the key parameters of the BSS of the AP where the link is located have been updated. In the response frame, the key update count value of the newly added link is carried; so that the Non-AP MLD can know whether the corresponding BSS key parameters have changed based on the key update count value.

[0194] In one possible implementation, non-AP MLD requires that the primary link it requests (specifies) must be accepted; otherwise, all requested links (i.e., links requested to be established by the target AP MLD) are rejected. For example, the protocol stipulates that the primary link requested (specified) by non-AP MLD must be accepted by the target AP MLD; otherwise, all requested links (i.e., links requested to be established by the target AP MLD) are rejected by the target AP MLD. Exemplarily, the target AP MLD can perform one of the following three operations: accept all the requested links (accept all the links that are requested), accept a subset of the requested links, where the subset of the requested links includes the primary link (accept a subset of the links that are requested, and the subset of the links include the primary link that is requested in the Roaming Request frame), or reject all requested links.

[0195] The key update count is a non-negative integer count value. When a BSS key parameter (which may be named a key BSS parameter) of the AP corresponding to the link ID is updated, the corresponding key update count value increases, for example, by 1. The BSS key parameter may include one or more of the following: channel switch announcement element, extended channel switch announcement element, enhanced distributed channel access (EDCA) parameter element, quiet element, DSSS parameter set, HT operation element, wide bandwidth channel switch element, channel switch wrapper element, operating mode notification element, quiet channel element, VHT (very high throughput) operation element, HE (high efficient) operation element, broadcast TWT element, BSS color change announcement element, MU EDCA parameter set element, element), spatial reuse parameter set element, UORA Parameter Set element, Index Adjustment Factor field in a Multiple BSSID Configuration element, EHT (extremely high throughput) operation element,The transmission power includes the element (Transmit Power Envelope element, if the AP is an EHT AP), and the UHR (ultra high reliability) operation element. One or more BSS key parameters can also be listed as key parameters of the link. In addition, the update events of BSS key parameters include one or more of the following: inclusion of channel switch announcement element, inclusion of extended channel switch announcement element, modification of enhanced distributed channel access,EDCA) parameter elements, including the inclusion of the quiet element, Modification of DSSS parameter set, Modification of HT operation element, including the inclusion of the wide bandwidth channel switch element, including the inclusion of the channel switch wrapper element, including the inclusion of the operating mode notification element, including the inclusion of the quiet channel element, Modification of the very high throughput (VHT) operation element, Modification of the high efficiency (HE) operation element, including the inclusion of the broadcast TWT element, Insertion or removal of a Broadcast TWT Parameter Set field in a Broadcast TWT element, including the inclusion of the BSS color change announcement element, and Modification of the MU EDCA parameter set element. element), Modification of spatial reuse parameter set element,Modification of the UORA Parameter Set element, Insertion of an Index Adjustment Factor field in a Multiple BSSID Configuration element, Modification of the EHT operation element, Inclusion, modification or removal of the Transmit Power Envelope element, if the AP is an EHT AP, Modification of the UHR operation element.

[0196] In one possible implementation, a station (a station in a non-AP MLD) will locally maintain the key update count corresponding to the link ID based on the link ID and key update count in the response frame. For example, after the station subsequently receives a management frame, such as a beacon frame or a probe response frame, to obtain the key update count corresponding to the link ID, it compares the local key update count with the most recently received key update count. If they are the same, it indicates that the key parameters of the BSS where the AP corresponding to the link ID is located have not been updated; otherwise, the key parameters of the BSS where the AP corresponding to the link ID is located have been updated. At this point, the non-AP MLD where the station is located can send a probe request frame to the AP MLD where the AP corresponding to the link ID is located through any station, requesting the key parameters of the BSS where the AP corresponding to the link ID is located. It then receives the latest parameters upon receiving the probe response frame. Alternatively, it receives the latest parameters upon receiving a beacon frame sent by the AP corresponding to the link ID.

[0197] In a possible implementation, the response frame further includes eighth indication information, and the eighth indication information is used to indicate whether roaming is performed between different AP MLDs in the same roaming domain or mobility domain, such as including a context transfer operation, or roaming is performed between different AP MLDs in different roaming domains or mobility domains, such as including a context transfer operation. The eighth indication information includes one bit or multiple bits. Exemplarily, when the value of the eighth indication information is 1, it is used to indicate roaming between different AP MLDs in the same roaming domain or mobility domain; when the value of the eighth indication information is 0, it is used to indicate roaming between different AP MLDs in different roaming domains or mobility domains. The roaming domain or mobility domain can also be expressed as a non-co-located AP MLD or a roaming AP MLD, and the non-co-located AP MLD or the roaming AP MLD includes multiple AP MLDs.

[0198] Step 1404 is optional. In one possible implementation, the first indication information in the request frame is used to indicate the target AP MLD for context transfer; if the first AP MLD or the target AP MLD rejects the request in the request frame or fails to complete the context transfer to the target AP MLD within a first time period after receiving the request frame, a response frame is sent to the non-AP MLD to indicate the rejection of the request frame.

[0199] In one possible implementation, the response frame is a Link Reconfiguration Response frame. Alternatively, the response frame can reuse the Link Reconfiguration Response frame. In one possible implementation, a new element is added to the Link Reconfiguration Response frame to carry the sixth and fifth indication information. In this implementation, reuse of the Link Reconfiguration Response frame can save signaling overhead.

[0200] Figure 17 is an example of a frame structure of a response frame provided in an embodiment of the present application. As shown in Figure 17, the response frame includes: a Category field, an MLD MAC address field (optional), link information (Link Info), and a scenario indication field (optional). The MLD MAC address field is used to indicate the MLD MAC address or MLD ID of the target AP MLD. The MLD MAC Address field is an example of the sixth indication information. Referring to Figure 17, the link information field includes the link ID of the link requested to be established (or added) in the request frame and the status code (statuscode) and critical update count value (criticalupdatecounter) corresponding to each link ID. The scenario indication field, that is, the eighth indication information mentioned above, is used to indicate whether to perform a context transfer operation between different AP MLDs under the same roaming AP MLD or a context transfer operation under different roaming AP MLDs.

[0201] In an embodiment of the present application, a non-AP MLD sends a request frame to a first AP MLD. Upon receiving the request frame, the first AP MLD performs a context transfer to a target AP MLD. The context associated with the non-AP MLD can be transferred to the target AP MLD so that the target AP MLD can subsequently establish a link association with the non-AP MLD based on the context, thereby implementing roaming of the non-AP MLD. Context transfer to the target AP MLD ensures that transmission of the non-AP MLD is not interrupted during roaming from the non-AP MLD to the target AP MLD, thereby implementing roaming that supports packet retransmission and reduces packet loss.

[0202] FIG18 is a flowchart of another method for multi-link device communication provided by an embodiment of the present application. The method flow of FIG18 is based on the method flow of FIG14, and adds the transmission operation related to the Non-AP MLD after the first AP MLD sends the response frame. As shown in FIG18, the method includes:

[0203] 1801. Non-AP MLD generates a request frame.

[0204] 1802. The Non-AP MLD sends a request frame to the first AP MLD.

[0205] 1803. The first AP MLD performs context transfer to the target AP MLD based on the request frame.

[0206] 1804. The first AP MLD sends a response frame to the non-AP MLD.

[0207] Steps 1801 to 1804 can refer to steps 1401 to 1404 in FIG. 14 , which will not be repeated here.

[0208] 1805. Data is transmitted between the non-AP MLD and the target AP MLD.

[0209] In one possible implementation, after receiving the response frame, the non-AP MLD establishes a link and / or association with the target AP MLD and performs data transmission. The target AP MLD may establish a link and / or association with the non-AP MLD based on the context from the first AP MLD and perform data transmission with the non-AP MLD. Exemplarily, the fifth indication information in the response frame indicates the status code and / or critical update count corresponding to the first link. Based on the fifth indication information, the non-AP MLD may determine that the target AP MLD accepts the established link and then establish a link and / or association with the target AP MLD.

[0210] 1806. The first AP MLD sends downlink data to the non-AP MLD.

[0211] In one possible implementation, the fourth indication information in the request frame indicates that the link state of the second link is enabled or awake after the response frame is sent. In another possible implementation, the fourth indication information in the request frame indicates that the link state of the first link is disabled or dormant after the response frame is sent. In this case, the non-AP MLD station operating on the first link can communicate with the first AP MLD. When the link state of the second link is enabled or awake, the first AP MLD sends the remaining data packets (i.e., downlink data) in the transmission queue to the non-AP MLD. The transmission queue includes data packets to be sent to the non-AP MLD. In this embodiment of the present application, after sending the response frame to the non-AP MLD, the first AP MLD may continue to send downlink data to the non-AP MLD. The order of steps 1806 and 1805 is not limited. Steps 1805 and 1806 can be performed in parallel. Step 1806 is optional.

[0212] 1807. The first AP MLD sends link deletion information to the non-AP MLD.

[0213] Correspondingly, the non-AP MLD receives link deletion information from the first AP MLD. The link deletion information instructs the non-AP MLD to delete (or disable) the link associated with the first AP MLD. In one possible implementation, when the last SN associated with the non-AP MLD on the first AP MLD is refreshed or times out, the link deletion information is sent to the non-AP MLD. This allows for timely link release and full utilization of link resources.

[0214] 1808. The non-AP MLD deletes the link associated with the first AP MLD based on the link deletion information.

[0215] In one possible implementation, steps 1807 and 1808 are replaced by: when the link quality between the non-AP MLD and the first AP MLD falls below a certain threshold, the non-AP MLD deletes the link associated with the first AP MLD and sends a message to the first AP MLD instructing the first AP MLD to delete the link between the non-AP MLD and the non-AP MLD. This improves resource utilization. The threshold can be set based on actual needs.

[0216] In this embodiment of the present application, after the first AP MLD sends a response frame to the non-AP MLD, it continues to send downlink data to the non-AP MLD until the last SN associated with the non-AP MLD on the first AP MLD is refreshed or times out. This allows the first AP MLD to send the remaining data packets in the transmission queue to the non-AP MLD, so that the non-AP MLD receives the complete downlink data from the first AP MLD. Roaming of the non-AP MLD is achieved by performing context transfer to the target AP MLD, thereby reducing packet loss.

[0217] Figure 19 is a flowchart of another method for multi-link device communication provided by an embodiment of the present application, which is optionally applicable to a single radio multi-link device (single radio MLD). The method flow of Figure 19 is based on the method flow of Figure 14, and adds the transmission operation related to the Non-AP MLD after the first AP MLD sends a response frame. The method flow in Figure 19 and the method flow in Figure 18 are two parallel method flows. The difference between the method flow in Figure 19 and the method flow in Figure 18 is that in the method flow of Figure 19, after sending the response frame, the first AP MLD no longer sends downlink data to the Non-AP MLD; in the method flow of Figure 18, after sending the response frame, the first AP MLD can continue to send downlink data to the Non-AP MLD. As shown in Figure 19, the method includes:

[0218] 1901. Non-AP MLD generates a request frame.

[0219] 1902. The Non-AP MLD sends a request frame to the first AP MLD.

[0220] 1903. The first AP MLD performs context transfer to the target AP MLD based on the request frame.

[0221] Steps 1901 to 1903 can refer to steps 1401 to 1403 in FIG. 14 , which will not be repeated here.

[0222] 1904. The first AP MLD sends downlink data to the non-AP MLD.

[0223] In one possible implementation, the fourth indication information in the request frame is used to indicate that the link state of the second link is disabled or dormant after the first AP MLD or the target AP MLD replies to the response frame. In another possible implementation, the fourth indication information in the request frame is used to indicate that the link state of the first link is enabled or awake after the response frame is replied. In this case, after the response frame is replied, the station of the non-AP MLD operating on the first link is disabled or dormant. If the link state of the second link is disabled or dormant, the first AP MLD sends the remaining data packets (i.e., downlink data) in the transmission queue to the non-AP MLD before sending the response frame to the non-AP MLD. The transmission queue includes data packets to be sent to the non-AP MLD.

[0224] 1905. The first AP MLD sends a response frame to the non-AP MLD.

[0225] For step 1905, please refer to step 1404 in FIG. 14 , which will not be described in detail here.

[0226] 1906. The non-AP MLD deletes the link of the first AP MLD.

[0227] In one possible implementation, the request frame may optionally include fourth indication information, where the fourth indication information is used to indicate the link status of a second link after the response frame is returned, where the second link includes the link between the first AP MLD and the non-AP MLD, and the link status of the second link is disabled or dormant; or the fourth indication information is used to indicate the link status of the first link after the response frame is returned, where the non-AP MLD learns the link status of the second link between the first AP MLD and the non-AP MLD according to a corresponding rule. In one possible implementation, the response frame may also include seventh indication information, where the seventh indication information is used to instruct the non-AP MLD to delete the link with the first AP MLD; the non-AP MLD deletes the link with the first AP MLD based on the seventh indication information. In one possible implementation, the protocol stipulates that the non-AP MLD deletes the link established with the first AP MLD after receiving the response frame.

[0228] 1907. Data is transmitted between the non-AP MLD and the target AP MLD.

[0229] Step 1907 can refer to step 1805 in Figure 18 and will not be repeated here.

[0230] In the embodiment of the present application, before sending a response frame to the non-AP MLD, the first AP MLD sends the remaining data packets in the transmission queue to the non-AP MLD. This allows the first AP MLD to send the remaining data packets in the transmission queue to the non-AP MLD, so that the non-AP MLD receives complete downlink data from the first AP MLD.

[0231] It should be understood that the size of the serial numbers of the above processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0232] It should also be understood that in the various embodiments of the present application, unless otherwise specified or there is a logical conflict, the terms and / or descriptions between different embodiments are consistent and can be referenced to each other, and the technical features in different embodiments can be combined to form new embodiments according to their internal logical relationships.

[0233] It should also be understood that in some of the above embodiments, devices in existing network architectures are mainly used as examples for illustrative purposes, and it should be understood that the embodiments of the present application do not limit the specific form of the devices. For example, devices that can achieve the same functions in the future are applicable to the embodiments of the present application.

[0234] It is understandable that in the above-mentioned various method embodiments, the methods and operations implemented by devices (such as non-AP MLD, first AP MLD, target AP MLD) may also be implemented by components applicable to the device (such as chips or circuits).

[0235] It can also be understood that some optional features in the various embodiments of the present application may not depend on other features in certain scenarios, and may also be combined with other features in certain scenarios, without limitation.

[0236] Those skilled in the art should be aware that, in combination with the units and algorithm steps of each example described in the embodiments disclosed herein, the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is performed in the form of hardware or computer software driving hardware 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 to be beyond the scope of this application.

[0237] The communication device provided in the embodiment of the present application is described in detail below with reference to Figures 20 to 22. It should be understood that the description of the device embodiment corresponds to the description of the method embodiment. Therefore, for matters not described in detail, reference can be made to the method embodiment above. For the sake of brevity, some contents are not repeated here.

[0238] In the embodiment of the present application, the functional modules of the transmitting device or the receiving device can be divided according to the above method example. For example, each functional module can be divided according to each function, or two or more functions can be integrated into one processing module. The above integrated modules can be implemented in the form of hardware or in the form of software functional modules. It should be noted that the division of modules in the embodiment of the present application is schematic and is only a logical functional division. There may be other division methods in actual implementation. The following is an example of dividing each functional module according to each function.

[0239] Figure 20 is a schematic block diagram of a communication device 10 provided in an embodiment of the present application. The device 10 includes a transceiver module 11 and a processing module 12. The transceiver module 11 can implement corresponding communication functions, and the processing module 12 is used to process data. In other words, the transceiver module 11 is used to perform operations related to receiving and sending, and the processing module 12 is used to perform other operations besides receiving and sending. The transceiver module 11 can also be referred to as a communication interface or a communication unit.

[0240] Optionally, the device 10 may further include a storage module 13, which may be used to store instructions and / or data. The processing module 12 may read the instructions and / or data in the storage module so that the device implements the actions of the devices in the aforementioned method embodiments.

[0241] In one design, the apparatus 10 may correspond to the non-AP MLD in the above method embodiments, or be a component (such as a chip) of the non-AP MLD.

[0242] The apparatus 10 can implement steps or processes corresponding to those executed by the non-AP MLD in the above method embodiment. The transceiver module 11 can be used to perform operations related to the transceiver reception and transmission of the non-AP MLD in the above method embodiment, and the processing module 12 can be used to perform operations related to the processing of the non-AP MLD in the above method embodiment.

[0243] It should be understood that the specific process of each unit executing the above corresponding steps has been described in detail in the above method embodiment, and for the sake of brevity, it will not be repeated here.

[0244] In another design, the device 10 may correspond to the first AP MLD in the above method embodiment, or a component (such as a chip) of the first AP MLD.

[0245] The apparatus 10 can implement steps or processes corresponding to those performed by the first AP MLD in the above method embodiment. The transceiver module 11 can be used to perform operations related to the transceiver operation of the first AP MLD in the above method embodiment, and the processing module 12 can be used to perform operations related to the processing of the first AP MLD in the above method embodiment.

[0246] It should be understood that the specific process of each unit executing the above corresponding steps has been described in detail in the above method embodiment, and for the sake of brevity, it will not be repeated here.

[0247] It should also be understood that the apparatus 10 herein is embodied in the form of functional modules. The term "module" herein may refer to an application specific integrated circuit (ASIC), an electronic circuit, a processor (e.g., a shared processor, a dedicated processor, or a group processor, etc.) and memory for executing one or more software or firmware programs, incorporating logic circuits, and / or other suitable components that support the described functionality.

[0248] The apparatus 10 of each of the above-described solutions has the function of implementing the corresponding steps performed by the device (e.g., the first AP MLD) in the above-described method. This function can be implemented by hardware, or by hardware executing corresponding software implementations. The hardware or software includes one or more modules corresponding to the above-described functions; for example, the transceiver module can be replaced by a transceiver (e.g., the transmitting unit in the transceiver module can be replaced by a transmitter, and the receiving unit in the transceiver module can be replaced by a receiver), and other units, such as the processing module, can be replaced by a processor to respectively perform the transceiver operations and related processing operations in each method embodiment.

[0249] In addition, the transceiver module 11 may also be a transceiver circuit (for example, may include a receiving circuit and a sending circuit), and the processing module may be a processing circuit.

[0250] Figure 21 is a schematic diagram of another communication device 20 provided in an embodiment of the present application. The device 20 includes a processor 21, which is configured to execute computer programs or instructions stored in a memory 22, or read data / signaling stored in the memory 22, to perform the methods described in the above method embodiments. Optionally, there are one or more processors 21.

[0251] Optionally, as shown in FIG21 , the device 20 further includes a memory 22 for storing computer programs or instructions and / or data. The memory 22 may be integrated with the processor 21 or may be separately provided. Optionally, there may be one or more memories 22.

[0252] Optionally, as shown in Figure 21, the device 20 further includes a transceiver 23, which is used to receive and / or send signals. For example, the processor 21 is used to control the transceiver 23 to receive and / or send signals.

[0253] As a solution, the apparatus 20 is configured to implement the operations performed by the non-AP MLD or the first AP MLD in the above various method embodiments.

[0254] It should be understood that the processor mentioned in the embodiments of the present application may be a central processing unit (CPU), or may be other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor, etc.

[0255] It should also be understood that the memory mentioned in the embodiments of the present application may be a volatile memory and / or a non-volatile memory. Among them, the non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM). For example, RAM can be used as an external cache. By way of example and not limitation, RAM includes the following forms: static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link dynamic random access memory (SLDRAM), and direct rambus RAM (DR RAM).

[0256] It should be noted that when the processor is a general-purpose processor, DSP, ASIC, FPGA or other programmable logic device, discrete gate or transistor logic device, discrete hardware component, the memory (storage module) can be integrated into the processor.

[0257] It should also be noted that the memory described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0258] 22 is a schematic diagram of a chip system 30 provided in an embodiment of the present application. The chip system 30 (or also referred to as a processing system) includes a logic circuit 31 and an input / output interface 32.

[0259] The logic circuit 31 may be a processing circuit in the chip system 30. The logic circuit 31 may be coupled to a storage unit and call instructions in the storage unit so that the chip system 30 can implement the methods and functions of the various embodiments of the present application. The input / output interface 32 may be an input / output circuit in the chip system 30, outputting information processed by the chip system 30 or inputting data or signaling information to be processed into the chip system 30 for processing.

[0260] As a solution, the chip system 30 is used to implement the operations performed by the non-AP MLD or the first AP MLD in the above various method embodiments.

[0261] For example, the logic circuit 31 is used to implement the processing-related operations performed by the non-AP MLD or the first AP MLD in the above method embodiment; the input / output interface 32 is used to implement the sending and / or receiving-related operations performed by the non-AP MLD or the first AP MLD in the above method embodiment.

[0262] An embodiment of the present application further provides a computer-readable storage medium on which computer instructions for implementing the methods executed by the device in the above-mentioned method embodiments are stored.

[0263] For example, when the computer program is executed by a computer, the computer can implement the method performed by the non-AP MLD or the first AP MLD in each embodiment of the above method.

[0264] An embodiment of the present application further provides a computer program product, comprising instructions, which, when executed by a computer, implement the methods performed by the non-AP MLD or the first AP MLD in the above-mentioned method embodiments.

[0265] An embodiment of the present application further provides a communication system, including a non-AP MLD, a first AP MLD, and a target AP MLD.

[0266] The explanation of the relevant contents and beneficial effects of any of the above-mentioned devices can be referred to the corresponding method embodiments provided above, which will not be repeated here.

[0267] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0268] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. For example, the computer can be a personal computer, a server, or a network device, etc. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from one website, computer, server or data center to another website, computer, server or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) mode. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more available media integrations. The available medium may be a magnetic medium (e.g., a floppy disk, a hard disk, a magnetic tape), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., a solid state disk (SSD)). For example, the aforementioned available medium includes, but is not limited to, various media that can store program code, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0269] 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 this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A method for multi-link device communication, characterized in that: The method is applied to a non-access point multi-link device (non-AP MLD), and the method includes: Generate a request frame, the request frame being used to request roaming to a target access point multi-link device (AP MLD), the request frame including first indication information, the first indication information being used to determine the target AP MLD; The request frame is sent to the first AP MLD.

2. The method according to claim 1, characterized in that The first indication information is used to indicate the target AP MLD, or the first indication information is a wildcard basic service set identifier BSSID.

3. The method according to claim 1 or 2, characterized in that The request frame further includes one or more pieces of second indication information, each piece of the second indication information is used to indicate a first link, where the first link is the link that the non-AP MLD requests the target AP MLD to establish.

4. The method according to claim 3, characterized in that The request frame further includes one or more of the following: third indication information or parameters used to establish one or more of the first links, where the third indication information is used to indicate a main link among the one or more first links.

5. The method according to any one of claims 1 to 4, characterized in that The request frame further includes fourth indication information, where the fourth indication information is used to indicate a link status of the first link after receiving the response frame.

6. The method according to claim 5, characterized in that The link state includes enable and disable, or the link state includes awake state and sleep state.

7. The method according to any one of claims 1 to 6, characterized in that The request frame further includes timeout information, and the timeout information is used to feed back the determination of the valid time of the response frame corresponding to the request frame.

8. The method according to any one of claims 1 to 7, characterized in that The request frame is a link reconfiguration request frame.

9. The method according to any one of claims 1 to 8, characterized in that The method further comprises: Receive a response frame from the first AP MLD, the response frame including fifth indication information, the fifth indication information being used to indicate a status code and / or a key update count value corresponding to the first link, the status code being used to indicate that the request to establish the first link is rejected or received, the key update count value being the number of times the basic service set BSS key parameters of the AP where the first link is located are currently updated, and when the BSS key parameters of the AP where the first link is located change, the key update count value increases by 1.

10. The method according to claim 9, characterized in that The response frame further includes sixth indication information, where the sixth indication information is used to indicate the target AP MLD.

11. The method according to claim 9 or 10, characterized in that The response frame is a link reconfiguration response frame.

12. A method for multi-link device communication, characterized in that: The method is applied to a first access point multi-link device AP MLD, and the method includes: receiving a request frame from a non-AP MLD, the request frame being used to request roaming to a target AP MLD, the request frame including first indication information, the first indication information being used to determine the target AP MLD; Perform context transfer to the target AP MLD.

13. The method according to claim 12, characterized in that The context includes Block ACK (BA) session-related parameters and / or security-related parameters.

14. The method according to claim 12 or 13, characterized in that The first indication information is used to indicate the target AP MLD, or the first indication information is a wildcard basic service set identifier BSSID.

15. The method according to claims 12 to 14, characterized in that The request frame further includes one or more pieces of second indication information, each piece of the second indication information is used to indicate a first link, where the first link is the link that the non-AP MLD requests the target AP MLD to establish.

16. The method according to claim 15, characterized in that The request frame further includes third indication information and at least one of parameters used to establish one or more first links, where the third indication information is used to indicate a main link among the one or more first links.

17. The method according to any one of claims 12 to 16, characterized in that The request frame further includes fourth indication information, where the fourth indication information is used to indicate a link status of the first link after receiving the response frame.

18. The method according to claim 17, characterized in that The link state includes enable and disable, or the link state includes awake state and sleep state.

19. The method according to any one of claims 12 to 18, characterized in that The request frame further includes timeout information, and the timeout information is used to feed back the determination of the valid time of the response frame corresponding to the request frame.

20. The method according to any one of claims 12 to 19, characterized in that The request frame is a link reconfiguration request frame.

21. The method according to any one of claims 12 to 20, characterized in that The method further comprises: A response frame is sent to the non-AP MLD, where the response frame includes fifth indication information, where the fifth indication information is used to indicate a status code and / or a key update count value corresponding to the first link, where the status code is used to indicate that the request to establish the first link is rejected or received, and where the key update count value is the number of times the basic service set (BSS) key parameters of the AP where the first link is located are currently updated. When the BSS key parameters of the AP where the first link is located change, the key update count value increases by 1.

22. The method according to claim 21, characterized in that The response frame further includes sixth indication information, where the sixth indication information is used to indicate the target AP MLD.

23. The method according to claim 22, characterized in that The request frame further includes fourth indication information, where the fourth indication information is used to indicate a link state of a first link after receiving the response frame, where the first link is the link that the non-AP MLD requests the target AP MLD to establish; After sending the response frame to the non-AP MLD, the method further includes: When the link state of the first link is disabled or in a dormant state, remaining data packets in a transmission queue are sent to the non-AP MLD, where the transmission queue includes data packets to be sent to the non-AP MLD. When the last sequence number SN associated with the non-AP MLD on the first AP MLD is refreshed or times out, link deletion information is sent to the non-AP MLD, where the link deletion information is used to instruct the non-AP MLD to delete the link of the first AP MLD.

24. The method according to any one of claims 21 to 23, characterized in that The response frame is a link reconfiguration response frame.

25. A communication device, characterized in that: The method comprises a processor coupled to a memory, the memory being used to store a computer program or instructions, the processor being used to execute the computer program or instructions in the memory, so that the communication device performs the method according to any one of claims 1 to 11; or, the communication device performs the method according to any one of claims 12 to 24.

26. A communication system, characterized in that: The communication system includes a first communication device and a second communication device; wherein the first communication device is used to perform the method according to any one of claims 1 to 11, and the second communication device is used to perform the method according to any one of claims 12 to 24.

27. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a computer program or instructions, and when the computer program or instructions are executed on a computer, the computer is caused to perform the method according to any one of claims 1 to 24.

28. A chip, characterized in that: include: A communication interface and a processor; the communication interface is used for sending and receiving signals of the chip; the processor is used to execute a computer program or instruction so that the communication device including the chip executes the method as described in any one of claims 1 to 24.

29. A computer program product, characterized in that When the computer program product is run on a computer, the computer is caused to perform the method according to any one of claims 1 to 24.

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