Communication method and apparatus

Abstract

Provided in the present application are a communication method and apparatus. The method comprises: a first access-point multi-link device determining that a station multi-link device has roamed from the first access-point multi-link device to a second access-point multi-link device, and storing first context information of the station multi-link device for a first duration. When determining that a station multi-link device completes roaming, a first access-point multi-link device stores, for a first duration, context information related to the station multi-link device, rather than immediately deleting the context information once the station multi-link device completes the roaming. Therefore, the additional overheads caused by repeated roaming of the station multi-link device can be effectively reduced, for example, the additional overheads caused by repeated context transfer or context re-negotiation in a roaming scenario can be reduced.

Description

Communication method and apparatus

[0001] Cross-reference to Related Applications

[0002] This application claims priority to the Chinese Patent Application No. 202411254650.9, filed on September 6, 2024, and entitled “A communication method and apparatus”, the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0003] The present application relates to the field of communication technology, and in particular, to a communication method and apparatus. BACKGROUND

[0004] Due to the movement of a none access point (non-AP) multi-link device (MLD) (also referred to as a station multi-link device), the non-AP MLD needs to switch its associated access point (AP) MLD. For example, when an AP MLD is providing services for a non-AP MLD, as the non-AP MLD moves, the signal quality of the communication connection between the non-AP MLD and the AP MLD gradually attenuates with the increasing distance. When the signal quality attenuates to a certain extent, the non-AP MLD is no longer suitable for communication connection with the AP MLD, and instead wishes to roam to (or switch to) another AP MLD with better signal quality in order to maintain normal data transmission.

[0005] However, during the roaming of the non-AP MLD, a ping-pong roaming (also referred to as back and forth roaming) problem can occur. Specifically, the non-AP MLD can repeatedly roam back and forth between at least two AP MLDs multiple times due to certain reasons, which can result in a large amount of additional overhead. In view of this, how to effectively reduce the additional overhead caused by the repeated roaming of the non-AP MLD becomes a problem to be solved. SUMMARY

[0006] The present application provides a communication method and apparatus to effectively reduce the additional overhead caused by the repeated roaming of a station multi-link device.

[0007] In a first aspect, the present application provides a communication method, which can be executed by a first access point multi-link device or a module (such as a processor, a processing unit, a chip system, a circuit or a chip, etc.) in the first access point multi-link device. Alternatively, the method can also be implemented by a logic node, a logic module or software which can implement all or part of the function of the first access point multi-link device. Exemplarily, the following takes the first access point multi-link device as an example to execute the communication method. The method can include the following steps: the first access point multi-link device determines that a station multi-link device roams from the first access point multi-link device to a second access point multi-link device, and saves first context information of the station multi-link device within a first time length.

[0008] In the method, the first access point multi-link device saves the context information (which can also be understood as the first access point multi-link device saves the context information related to the station multi-link device within a period of time after the station multi-link device completes the roaming) for the station multi-link device (which can also be referred to as a non-access point multi-link device) that completes the roaming for a period of time (such as the first time length), instead of deleting the context information immediately after the station multi-link device completes the roaming, so that the additional overhead caused by repeated roaming of the station multi-link device can be effectively reduced, such as the additional overhead caused by repeated context transfer or context re-negotiation in the roaming scenario.

[0009] Based on the first aspect, in a possible implementation, the method further includes: the first access point multi-link device sends first information to the station multi-link device, wherein the first information can be used to indicate that the context information is supported to be saved, or the first information can be used to indicate that the second context information supported to be saved, and the second context information can include the first context information; and then the first access point multi-link device receives second information from the station multi-link device, wherein the second information can be used to indicate that the context information of the station multi-link device is saved, or the second information can be used to indicate the identification of the first context information.

[0010] In the above implementation, the first access point multi-link device and the station multi-link device perform context information saving capability interaction to indicate whether to save the context information or to indicate which context information to save, so that the context information saving can be better implemented, and the resource waste caused by meaningless context information saving (or saving the context information) can be avoided.

[0011] Based on the first aspect, in a possible implementation, the method further includes:

[0012] The first access point multi-link device can send third information to the station multi-link device, wherein the third information is used to indicate the first time length.

[0013] In the implementation manner, the first access point multi-link device can send the third information to the station multi-link device, so that the station multi-link device can learn the storage time (or the storage expiration time) of the context information related to the station multi-link device in time, and then the station multi-link device can learn that the context information stored by the first access point multi-link device can be reused (or used) only when the station multi-link device roams back to the first access point multi-link device within the first time length.

[0014] With reference to the first aspect, in a possible implementation manner, the method further includes:

[0015] When (or after) receiving the first roaming request from the station multi-link device, or when (or after) sending the first roaming response to the station multi-link device, the first access point multi-link device can start a timer, wherein the timing length of the timer is the first time length, the first roaming request corresponds to the first roaming response, and the first roaming request is used to request roaming from the first access point multi-link device to the second access point multi-link device. After that, when the timer does not time out, the first access point multi-link device can store the first context information, or when the timer times out, the first access point multi-link device can delete the first context information.

[0016] The implementation manner can ensure that the time interval between two roaming requests (i.e., the first roaming request and the second roaming request for roaming back to the first access point multi-link device) does not exceed the first time length, or can ensure that the time interval between the last roaming response and the next roaming request (i.e., the first roaming response and the second roaming request for roaming back to the first access point multi-link device) does not exceed the first time length, so that the first context information stored by the first access point multi-link device can be reused.

[0017] In a second aspect, the present application provides a communication method, which can be executed by a station multi-link device or a module (such as a processor, a processing unit, a chip system, a circuit or a chip, etc.) in the station multi-link device. Alternatively, the method can also be implemented by a logic node, a logic module or software which can implement all or part of the functions of the station multi-link device. Exemplarily, the following takes the station multi-link device as an example to execute the communication method. The method can include the following steps: the station multi-link device receives first information from a first access point multi-link device, wherein the first information can be used to indicate that the context information is supported to be saved, or the first information can be used to indicate that the second context information is supported to be saved, the second context information can include the first context information, the first context information can be the context information saved by the first access point multi-link device when the station multi-link device roams from the first access point multi-link device to a second access point multi-link device, and the first context information is saved for a first time length. Then, the station multi-link device can send second information to the first access point multi-link device, wherein the second information can be used to indicate that the context information of the station multi-link device is saved, or the second information can be used to indicate the identification of the first context information.

[0018] The technical effects achieved by the second aspect can refer to the technical effects achieved by the corresponding implementation manners provided by the first aspect, which will not be repeated here.

[0019] Based on the second aspect, in a possible implementation manner, the method further includes:

[0020] The station multi-link device can receive third information from the first access point multi-link device, wherein the third information is used to indicate the first time length.

[0021] The technical effects achieved by the above implementation manners can refer to the technical effects achieved by the corresponding implementation manners provided by the first aspect, which will not be repeated here.

[0022] Based on the first aspect or the second aspect, in a possible implementation manner, the third information can carry a timeout interval element, and the timeout interval element includes the first time length.

[0023] The above implementation manner can define a new type in the timeout interval element reserved or reserved to indicate the first time length, which is simple and can effectively utilize the timeout interval element.

[0024] Based on the first aspect or the second aspect, in a possible implementation manner, the third information can be one of the following: a beacon frame, a probe response frame, an association response frame, and a re-association response frame.

[0025] In the implementation manner, the third information is for one of the beacon frame, the probe response frame, the association response frame, or the re-association response frame, so that the station multi-link device can learn the first time length in time (or earlier).

[0026] In a possible implementation manner of the first aspect or the second aspect, the context information can include at least one of the following: a pairwise transient key, a block acknowledgement, a flow classification service, a mirror flow classification service, a target wake-up time, a traffic identifier and a link-to-link mapping, and an emergency preparedness communication service.

[0027] The context information is closely related to data transmission of the station multi-link device, so that the context information transfer when switching the access point multi-link device can ensure the continuity of data transmission, thereby realizing seamless roaming.

[0028] In a possible implementation manner of the first aspect or the second aspect, the first time length can be a preset context information holding time length, or the first time length can be a roaming deadline.

[0029] In the implementation manner, the existing roaming deadline (or re-association deadline) is multiplexed as the first time length, so that the first access point multi-link device does not need to provide the first time length to the station multi-link device, which helps to save communication overhead.

[0030] In a third aspect, the present application provides a communication method, which can be executed by the first access point multi-link device or a module (such as a processor, a processing unit, a chip system, a circuit or a chip, etc.) in the first access point multi-link device. Optionally, the method can also be implemented by a logical node, a logical module or software capable of implementing all or part of the functions of the first access point multi-link device. Exemplarily, the following takes the first access point multi-link device executing the communication method as an example. The method can include the following steps: the first access point multi-link device determines that a station multi-link device roams from the first access point multi-link device to a second access point multi-link device, and holds a setting link between the first access point multi-link device and the station multi-link device within a second time length.

[0031] In the method, the first access point multi-link device maintains the set link between the first access point multi-link device and the station multi-link device for a period of time (such as the second time length) after the station multi-link device completes roaming, so that the set link between the first access point multi-link device and the station multi-link device can be reused when the station multi-link device roams back to the first access point multi-link device within the first time length, thereby effectively avoiding the need for the station multi-link device to add a link again when roaming back to the first access point multi-link device, and effectively reducing the additional overhead caused by the need for the station multi-link device to add a link again when roaming back to the first access point multi-link device. In addition, based on the first access point multi-link device maintaining the set link between the first access point multi-link device and the station multi-link device for a period of time (such as the second time length) after the station multi-link device completes roaming, the context information of the station multi-link device is also saved to some extent, achieving the effect of saving context information, that is, the additional overhead caused by repeatedly transferring or re-negotiating context in the repeated roaming scenario can be reduced.

[0032] Based on the third aspect, in a possible implementation manner, the method further includes: the first access point multi-link device sends fourth information to the station multi-link device, where the fourth information can be used to indicate that the set link is supported to be maintained, and then the first access point multi-link device can receive fifth information from the station multi-link device, where the fifth information is used to indicate that the set link between the first access point multi-link device and the station multi-link device is maintained.

[0033] In the above implementation manner, the first access point multi-link device and the station multi-link device perform set link maintenance capability interaction to indicate whether the set link is maintained, so that the set link maintenance can be better implemented, the context information of the station multi-link device can be saved to some extent, the effect of saving context information can be achieved, and resource waste caused by meaningless set link maintenance can be avoided.

[0034] Based on the third aspect, in a possible implementation manner, the method further includes:

[0035] The first access point multi-link device can send sixth information to the station multi-link device, where the sixth information can be used to indicate the second time length.

[0036] In the implementation manner, the first access point multi-link device can facilitate the station multi-link device to learn the save duration (or save expiration time) of the setup link between the first access point multi-link device and the station multi-link device in time by sending the sixth information to the station multi-link device, so that the station multi-link device can learn that the setup link between the first access point multi-link device and the station multi-link device can be reused only when the station multi-link device roams back to the first access point multi-link device within the second duration.

[0037] In a possible implementation manner based on the third aspect, the method further includes:

[0038] When (or after) receiving the first roaming request from the station multi-link device, or when (or after) sending the first roaming response to the station multi-link device, the first access point multi-link device can start a timer, where a timing duration of the timer is the second duration, the first roaming request corresponds to the first roaming response, and the first roaming request is used to request roaming from the first access point multi-link device to the second access point multi-link device. After that, when the timer does not time out, the first access point multi-link device can save the setup link between the first access point multi-link device and the station multi-link device, or when the timer times out, the first access point multi-link device can delete the setup link between the first access point multi-link device and the station multi-link device.

[0039] The implementation manner can implement that a time interval between two roaming requests (i.e., the first roaming request and the second roaming request for roaming back to the first access point multi-link device) cannot exceed the first duration, or can implement that a time interval between a last roaming response and a next roaming request (i.e., the first roaming response and the second roaming request for roaming back to the first access point multi-link device) cannot exceed the first duration, so that the setup link between the first access point multi-link device and the station multi-link device that has been saved can be reused.

[0040] In a fourth aspect, a communication method is provided. The method can be performed by a station multi-link device or a module (e.g., a processor, a processing unit, a chip system, a circuit, or a chip) in the station multi-link device. Alternatively, the method can also be implemented by a logic node, a logic module, or software that can implement all or part of the functions of the station multi-link device. For example, the method performed by the station multi-link device is described below. The method can include the following steps: receiving, by the station multi-link device, fourth information from a first access point multi-link device, wherein the fourth information can be used to indicate that the set link is supported to be saved, and then sending, by the station multi-link device, fifth information to the first access point multi-link device, wherein the fifth information is used to indicate that the set link between the first access point multi-link device and the station multi-link device is saved, and the saving duration of the set link is a second duration.

[0041] The technical effects achieved by the fourth aspect can refer to the technical effects achieved by the corresponding implementation manners of the third aspect, which will not be described herein.

[0042] Based on the fourth aspect, in a possible implementation, the method further includes:

[0043] The station multi-link device can receive sixth information from the first access point multi-link device, wherein the sixth information can be used to indicate the second duration.

[0044] The technical effects achieved by the above implementation manners can refer to the technical effects achieved by the corresponding implementation manners of the third aspect, which will not be described herein.

[0045] Based on the third aspect or the fourth aspect, in a possible implementation, the sixth information can carry a timeout interval element, and the timeout interval element includes the second duration.

[0046] The above implementation manner can define a new type in the timeout interval element reserved or reserved to indicate the second duration, which is simple and can effectively utilize the timeout interval element.

[0047] Based on the third aspect or the fourth aspect, in a possible implementation, the sixth information can be one of the following: a beacon frame, a probe response frame, an association response frame, and a re-association response frame.

[0048] In the above implementation, based on the sixth information being one of the beacon frame, the probe response frame, the association response frame, or the re-association response frame, the station multi-link device can learn the second duration in time (or earlier).

[0049] Based on the third aspect or the fourth aspect, in a possible implementation, the second duration can be a preset context information saving duration, or the second duration can be a roaming cutoff duration.

[0050] In the above implementation, by multiplexing the existing roaming timeout (or re-association timeout) as the first timeout, the first access point multi-link device does not need to additionally provide the second timeout to the station multi-link device, which helps to save communication overhead.

[0051] In a fifth aspect, a communication method is provided, which can be performed by a first access point multi-link device or a module (such as a processor, a processing unit, a chip system, a circuit or a chip, etc.) in the first access point multi-link device. Optionally, the method can also be implemented by a logical node, a logical module or software capable of implementing all or part of the functions of the first access point multi-link device. It can be understood that the method can also be performed by a second access point multi-link device or a module (such as a processor, a processing unit, a chip system, a circuit or a chip, etc.) in the second access point multi-link device. Optionally, the method can also be implemented by a logical node, a logical module or software capable of implementing all or part of the functions of the second access point multi-link device. Exemplarily, the following takes the first access point multi-link device or the second access point multi-link device as an example to perform the communication method. The method can include the following steps: the first access point multi-link device or the second access point multi-link device receives seventh information from a station multi-link device, wherein the seventh information can be used to request to roam from the first access point multi-link device to the second access point multi-link device, and then the first access point multi-link device or the second access point multi-link device can send eighth information to the station multi-link device, wherein the eighth information can be used to indicate a context information transfer result, and the context information transfer result can include context information that has been accepted by the second access point multi-link device and / or context information that has not been accepted by the second access point multi-link device.

[0052] In the method, by sending the eighth information to the station multi-link device, the first access point multi-link device or the second access point multi-link device can make the station multi-link device know the context information transfer result in time, so that the station multi-link device can clearly know which context information has been accepted by the second access point multi-link device and which context information has not been accepted by the second access point multi-link device, thereby effectively avoiding the problem of continuity of data transmission between the station multi-link device and the second access point multi-link device due to the station multi-link device mistakenly thinking that some context information has been successfully accepted by the second access point multi-link device.

[0053] Based on the fifth aspect, in a possible implementation, the method further includes:

[0054] The first access point multi-link device or the second access point multi-link device can receive ninth information from the station multi-link device, where the ninth information can be used to indicate whether context information transfer is needed, or the ninth information can be used to indicate an identity of the context information that needs to be transferred.

[0055] In the above implementation, considering that the context information transferred to the second access point multi-link device can not be accepted by the second access point multi-link device, the station multi-link device can not want to perform context information transfer, but rather re-negotiate the context information with the second access point multi-link device after completing roaming, and therefore the station multi-link device sends indication information that context information transfer is not needed, or indication information that some or part of the context information transfer is needed, to the first access point multi-link device or the second access point multi-link device, which can effectively reduce the additional overhead caused by context information transfer.

[0056] In a sixth aspect, the present application provides a communication method, which can be executed by a station multi-link device or a module (such as a processor, a processing unit, a chip system, a circuit, or a chip) in the station multi-link device. Optionally, the method can also be implemented by a logical node, a logical module, or software that can implement all or part of the functions of the station multi-link device. Exemplarily, the following takes the station multi-link device as an example to execute the communication method. The method can include the following steps: the station multi-link device sends seventh information to the first access point multi-link device or the second access point multi-link device, where the seventh information can be used to request roaming from the first access point multi-link device to the second access point multi-link device, and then the station multi-link device receives eighth information from the first access point multi-link device or the second access point multi-link device, where the eighth information can be used to indicate a context information transfer result, and the context information transfer result can include context information that has been accepted by the second access point multi-link device and / or context information that has not been accepted by the second access point multi-link device.

[0057] The technical effects achieved by the sixth aspect are the same as those achieved by the fifth aspect, which will not be repeated here.

[0058] Based on the sixth aspect, in a possible implementation, the method further includes:

[0059] The station multi-link device can send ninth information to the first access point multi-link device or the second access point multi-link device, where the ninth information can be used to indicate whether context information transfer is needed, or the ninth information can be used to indicate an identity of the context information that needs to be transferred.

[0060] The technical effects achieved by the above implementation manners can refer to the technical effects achieved by the corresponding implementation manners provided in the fifth aspect, which will not be described herein.

[0061] Based on the fifth aspect or the sixth aspect, in a possible implementation manner, if the context information transfer result includes context information that is not accepted by the second access point multi-link device, the eighth information can further include third context information recommended by the second access point multi-link device, where the third context information corresponds to the context information that is not accepted by the second access point multi-link device.

[0062] The above implementation manners can enable the station multi-link device to learn in a timely manner what kind of context information can be accepted by the second access point multi-link device, and help the station multi-link device to perform re-negotiation with the second access point multi-link device in a timely manner, thereby effectively improving the re-negotiation efficiency.

[0063] In the seventh aspect, the present application provides a communication apparatus, including units or means for performing each step of any possible implementation manner of the first aspect or the third aspect or the fifth aspect.

[0064] For example, the communication apparatus can be the first access point multi-link device, and can also be a module (such as a processor, a processing unit, a chip system, a circuit or a chip, etc.) in the first access point multi-link device. The communication apparatus has the function of implementing the method in any possible implementation manner of the first aspect or the third aspect or the fifth aspect. The function can be implemented by hardware, or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above functions.

[0065] In the eighth aspect, the present application provides a communication apparatus, including units or means for performing each step of any possible implementation manner of the second aspect or the fourth aspect or the sixth aspect.

[0066] For example, the communication apparatus can be the station multi-link device, and can also be a module (such as a processor, a processing unit, a chip system, a circuit or a chip, etc.) in the station multi-link device. The communication apparatus has the function of implementing the method in any possible implementation manner of the second aspect or the fourth aspect or the sixth aspect. The function can be implemented by hardware, or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above functions.

[0067] In a ninth aspect, the present application provides a communication apparatus, which implements the functions of the first aspect to the sixth aspect, for example, the communication apparatus includes modules or units or means corresponding to the operations of the first aspect to the sixth aspect, and the functions or units or means can be implemented by software or by hardware, or by a combination of hardware and software.

[0068] In a possible implementation, the communication apparatus can include a processing unit (or a processing module). Optionally, the communication apparatus can also include a transceiver unit (or a communication module or a transceiver module or a communication module, for transmitting and receiving data). The transceiver unit can be used to transceive signals to realize communication between the communication apparatus and other apparatuses, for example, the transceiver unit is used to transmit data to other communication apparatuses; the processing unit can be used to perform some internal operations of the communication apparatus. The functions performed by the transceiver unit and the processing unit can correspond to the operations of the first aspect to the sixth aspect.

[0069] In a possible implementation, the communication apparatus includes a processor, which can be coupled with a memory. The memory can store necessary computer programs or instructions for implementing the functions of the first aspect to the sixth aspect. The processor can execute the computer programs or instructions stored in the memory, and when the computer programs or instructions are executed, the communication apparatus can implement the method in any possible implementation of any one of the first aspect to the sixth aspect.

[0070] In a possible implementation, the communication apparatus includes a processor and a memory, and the memory can store necessary computer programs or instructions for implementing the functions of the first aspect to the sixth aspect. The processor can execute the computer programs or instructions stored in the memory, and when the computer programs or instructions are executed, the communication apparatus can implement the method in any possible implementation of any one of the first aspect to the sixth aspect.

[0071] In a possible implementation, the communication apparatus includes a processor and a transceiver (or a communication interface or an interface circuit), wherein the processor is configured to communicate with other apparatuses through the transceiver and perform the method in any possible implementation of any one of the first aspect to the sixth aspect. The transceiver is configured to realize communication between the communication apparatus and other apparatuses, for example, to receive signals from other communication apparatuses and transmit the signals to the processor or transmit signals from the processor of the communication apparatus to other communication apparatuses, for example, transmission or reception of data and / or signals. Exemplarily, the communication interface can be a transceiver, a circuit, a bus, a module or other types of communication interfaces.

[0072] It can be understood that, in the ninth aspect, the processor can be implemented by hardware or software. When implemented by hardware, the processor can be a logic circuit, an integrated circuit, etc. When implemented by software, the processor can be a general-purpose processor, which implements by reading software codes stored in the memory. In addition, the processor can be one or more, and the memory can be one or more. The memory can be integrated with the processor, or the memory and the processor can be separately arranged. In the implementation process, the memory can be integrated on the same chip as the processor, or can be separately arranged on different chips. The type of the memory and the arrangement manner of the memory and the processor are not limited in the embodiments of the present application.

[0073] In the tenth aspect, the present application provides a possible communication system, which can include the station multi-link device, the first access point multi-link device, the second access point multi-link device, etc. mentioned in the first aspect or the second aspect or the third aspect or the fourth aspect or the fifth aspect or the sixth aspect. The related functions of the station multi-link device, the first access point multi-link device, or the second access point multi-link device can be implemented by referring to the related descriptions in the first aspect or the second aspect or the third aspect or the fourth aspect or the fifth aspect or the sixth aspect, which will not be repeated here.

[0074] In the eleventh aspect, the present application provides a computer program product, which includes computer programs or instructions, and when the computer programs or instructions are executed on a communication device (or a computer), the communication device (or the computer) executes the method in any possible implementation manner of any one of the first aspect to the sixth aspect.

[0075] In the twelfth aspect, the present application provides a computer readable storage medium, which stores computer programs or instructions, and when the computer programs or instructions are executed by a communication device (or a computer), the communication device (or the computer) executes the method in any possible implementation manner of any one of the first aspect to the sixth aspect.

[0076] In the thirteenth aspect, the present application provides a chip, which can include a processor and can also include a memory (or the chip is coupled with the memory). The chip executes program instructions in the memory, so that the chip executes the method in any possible implementation manner of any one of the first aspect to the sixth aspect. The "coupling" means that two components are directly or indirectly combined with each other, such as the electrical connection between the two components.

[0077] In a fourteenth aspect, the present application also provides a chip system, which comprises a processor for supporting a computer device to implement the method in any possible implementation manner of any one of the first aspect to the sixth aspect. In a possible implementation manner, the chip system further comprises a memory for storing the necessary programs and data of the computer device. The chip system can be composed of a chip, or can include a chip and other discrete devices.

[0078] On the basis of the implementation manners of the above aspects, the present application can be further combined to provide more implementation manners. BRIEF DESCRIPTION OF DRAWINGS

[0079] FIG. 1 exemplarily shows a network architecture of a WLAN provided by an embodiment of the present application;

[0080] FIG. 2a exemplarily shows a possible roaming scenario provided by an embodiment of the present application;

[0081] FIG. 2b exemplarily shows another possible roaming scenario provided by an embodiment of the present application;

[0082] FIG. 3 exemplarily shows a link between a Non-AP MLD and an AP MLD provided by an embodiment of the present application;

[0083] FIG. 4 exemplarily shows a flow of a communication method provided by an embodiment of the present application;

[0084] FIG. 5 exemplarily shows a structure of a timeout interval element provided by an embodiment of the present application;

[0085] FIG. 6 exemplarily shows a flow of another communication method provided by an embodiment of the present application;

[0086] FIG. 7 exemplarily shows a flow of still another communication method provided by an embodiment of the present application;

[0087] FIG. 8 exemplarily shows a flow of still another communication method provided by an embodiment of the present application;

[0088] FIG. 9 exemplarily shows another link between a Non-AP MLD and an AP MLD provided by an embodiment of the present application;

[0089] FIG. 10 exemplarily shows a flow of still another communication method provided by an embodiment of the present application;

[0090] FIG. 11 exemplarily shows a flow of still another communication method provided by an embodiment of the present application;

[0091] FIG. 12 exemplarily shows a structure of a possible communication device provided by an embodiment of the present application;

[0092] FIG. 13 shows a schematic diagram of another possible communication apparatus provided by the embodiments of the present application. DETAILED DESCRIPTION

[0093] Before introducing the technical solutions provided by the present application, first, some terms involved in the present application are explained and described, so as to facilitate the understanding of those skilled in the art.

[0094] MLD: refers to a device that has multiple radio frequency modules at the same time, which work on different frequency bands / channels. When the channel spacing of two radio frequency modules in a device is large enough, they can not interfere with each other and can operate independently. If any two links support simultaneous transmission and reception (simultaneous transmit and receive, STR) on one link while the other link is receiving, it can be considered that the two links support simultaneous transmission and reception (non-simultaneous transmit and receive, NSTR).

[0095] The embodiments of the present application will be described in detail below with reference to the drawings.

[0096] The network architecture to which the communication method provided by the present application is applicable will be introduced below. It should be noted that these introductions are for the convenience of those skilled in the art to understand, and do not limit the scope of protection required by the present application.

[0097] The embodiments of the present application can be applicable to WLAN scenarios, for example, can be applicable to IEEE 802.11 system standards, such as 802.11be standard, wireless fidelity (WiFi) 7 or extremely high throughput (EHT), 802.11bf, or 802.11be next generation, such as WiFi 8 or more next generation standards. Or the embodiments of the present application can also be applicable to wireless local area network systems such as Internet of Things (IoT) networks or Vehicle to X (V2X) networks. Of course, the embodiments of the present application can also be applicable to other possible communication systems, such as worldwide interoperability for microwave access (WiMAX) communication systems, 5G communication systems, and future communication systems.

[0098] Hereinafter, the embodiments of the present application can be applicable to a WLAN scenario. It should be understood that the WLAN starts from the 802.11a / g standard, goes through 802.11n, 802.11ac, 802.11ax, and 802.11be which is currently discussed. Among them, 802.11n can also be referred to as high throughput (HT); 802.11ac can also be referred to as very high throughput (VHT); 802.11ax can also be referred to as high efficiency (HE) or WiFi 6; 802.11be can also be referred to as EHT or WiFi 7, and the standards before HT, such as 802.11a / b / g, etc. can be collectively referred to as Non-HT.

[0099] FIG. 1 exemplarily shows a network architecture diagram of a WLAN to which the embodiments of the present application are applicable. As shown in FIG. 1, the network architecture can include one or more access point type stations and one or more non-access point type stations (non-AP STAs). For ease of description, the access point type station is referred to as an access point (AP) and the non-access point type station is referred to as a station (STA) in the present application. FIG. 1 takes the network architecture including one AP and six stations (STA 1, STA 2, STA 3, STA 4, STA 5, and STA 6) as an example for illustration. It can be understood that the STA associated with the AP can receive the wireless frame sent by the AP and can also send the wireless frame to the AP. In addition, the embodiments of the present application are also applicable to the communication between APs, for example, the APs can communicate with each other through a distributed system (DS). It should be understood that the number of APs and STAs in FIG. 1 is only an example, and there can be more or less.

[0100] The access point can be an access point for a terminal device (such as a mobile phone) to enter a wired (or wireless) network, and is mainly deployed in a home, a building, and a park, and has a typical coverage radius of tens of meters to hundreds of meters, and can also be deployed outdoors. The access point is equivalent to a bridge connecting a wired network and a wireless network, and mainly functions to connect various wireless network clients together and then access the wireless network to an Ethernet. Specifically, the access point can be a terminal device (such as a mobile phone) or a network device (such as a router) with a WiFi chip. The access point can be a device supporting the 802.11bn standard, and the access point can also be a device supporting multiple WLAN standards of the 802.11 family such as 802.11be, 802.11ax, 802.11n, 802.11g, 802.11b, and 802.11a. The access point in this application can be a VHT access point, an HE access point, or an EHT access point, and can also be an access point applicable to a future generation of WiFi standards.

[0101] The station can be a wireless communication chip, a wireless sensor, or a wireless communication terminal, and can also be referred to as a user. For example, the station can be a mobile phone supporting WiFi communication, a tablet computer supporting WiFi communication, a set-top box supporting WiFi communication, a smart television supporting WiFi communication, a smart wearable device supporting WiFi communication, a vehicle-mounted communication device supporting WiFi communication, and a computer supporting WiFi communication, and the like. Alternatively, the station can support the 802.11bn standard, and the station can also support multiple WLAN standards of the 802.11 family such as 802.11be, 802.11ax, 802.11ac, 802.11n, 802.11g, 802.11b, and 802.11a. The station in this application can be a VHT station, an HE station, or an EHT station, and can also be a station applicable to a future generation of WiFi standards.

[0102] For example, the access point and the station can be devices applied to the Internet of Vehicles, Internet of Things nodes, sensors, smart cameras, smart remote controls, smart water meters, and sensors in a smart city, and the like.

[0103] The AP involved in FIG. 1 can be an MLD with multi-link communication function, referred to as an access point multi-link device (AP MLD); the STA involved in FIG. 1 can be an MLD with multi-link communication function, referred to as a non-access point multi-link device or a station multi-link device (Non-AP MLD). The AP MLD and the Non-AP MLD have multiple radio frequency modules, which work on different frequency bands or channels or links. For example, the frequency bands in which the AP MLD and the Non-AP MLD work can be all or part of sub-1 gigahertz (GHz), 2.4 GHz, 5 GHz, 6 GHz, and high frequency 60 GHz, which is not limited here. Among them, one AP MLD can include one or more affiliated stations, such as an AP, and one Non-AP MLD can also include one or more affiliated stations, such as a non-AP STA (also referred to as a STA). Each affiliated station has its own media access control (MAC) address. The MLD can aggregate a larger bandwidth and also use multi-link cooperation technology, such as sharing the MAC layer on multiple links to implement flexible transmission of message packets or simultaneously send message packets of the same service to the same station. The AP MLD and the Non-AP MLD can establish association through a link, thereby quickly establishing association of multiple links.

[0104] In the embodiments of the present application, the Non-AP MLD may, due to factors such as movement, switch the associated AP MLD. For example, due to the movement of the Non-AP MLD, it moves from the coverage range (or coverage area) of the current AP MLD to the coverage range of the target AP MLD. Therefore, it can be necessary to switch the AP MLD associated with the Non-AP MLD, such as switching the AP MLD associated with the Non-AP MLD from the current AP MLD to the target AP MLD. Specifically, when the AP MLD provides services for the Non-AP MLD, the signal quality will attenuate as the distance between the AP MLD and the Non-AP MLD gradually increases. When the signal quality of the connection between the AP MLD and the Non-AP MLD drops to a certain extent, the Non-AP MLD is no longer suitable for communication connection (or association) with the AP MLD, but hopes to roam to (or switch to) another AP MLD with better signal quality in order to maintain normal data transmission.

[0105] For example, FIG. 2a is a schematic diagram of a possible roaming scenario provided by an embodiment of the present application. As shown in FIG. 2a, taking the example of a Non-AP MLD roaming from a current AP MLD to a target AP MLD. When the signal quality of the connection between the Non-AP MLD and the current AP MLD falls to a certain extent, the Non-AP MLD can request to roam (or switch) from the current AP MLD to the target AP MLD.

[0106] For another example, FIG. 2b is a schematic diagram of another possible roaming scenario provided by an embodiment of the present application. As shown in FIG. 2b, taking the example of a Non-AP MLD including two STAs (such as STA1' and STA2'), a current AP MLD being AP MLD1, and a target AP MLD being AP MLD2. It is assumed that the current AP MLD includes two APs, namely AP1-1 and AP1-2. It is assumed that the target AP MLD includes two APs, namely AP2-1 and AP2-2. When the Non-AP MLD is connected to the current AP MLD, STA1' in the Non-AP MLD establishes a communication link with AP1-1 in the current AP MLD, and STA2' in the Non-AP MLD establishes a communication link with AP1-2 in the current AP MLD. When the signal quality of the connection between the Non-AP MLD and AP MLD1 falls to a certain extent, the Non-AP MLD can request to roam from AP MLD1 to AP MLD2. That is, STA1' in the Non-AP MLD can roam from AP1-1 to AP2-1 in AP MLD2 (i.e., the communication link between STA1' and AP1-1 is disconnected, and a communication link is established between STA1' and AP2-1), and STA2' in the Non-AP MLD can roam from AP1-2 to AP2-2 in AP MLD2 (i.e., the communication link between STA2' and AP2-1 is disconnected, and a communication link is established between STA2' and AP2-2).

[0107] In the present example, a Non-AP MLD can include multiple links, each of which corresponds to a different STA entity. The multiple STA entities are independent of each other at a low MAC layer and a physical (PHY) layer, and share a high MAC layer. The multiple STA entities usually work on different frequency bands or channels or links. Similarly to a Non-AP MLD, an AP MLD can include multiple links, each of which corresponds to a different AP entity. The multiple AP entities are independent of each other at a low MAC layer and a PHY layer, and share a high MAC layer. The multiple AP entities usually work on different frequency bands or channels.

[0108] As shown in FIG. 3, the AP MLD includes AP1 and AP2, AP1 includes AP1 PHY, AP1 lower layer MAC and high layer MAC, AP2 includes AP2 PHY, AP2 lower layer MAC and high layer MAC. Among them, the high layer MAC is shared between AP1 and AP2, the Non-AP MLD includes STA1” and STA2”, STA1” includes STA1” PHY, STA1” lower layer MAC and high layer MAC, STA2” includes STA2” PHY, STA2” lower layer MAC and high layer MAC, wherein the high layer MAC is shared between STA1 and STA2, AP1 and STA1” are connected through link1, and AP2 and STA2” are connected through link2.

[0109] In the multi-link establishment, the Non-AP MLD sends an Association Request frame on link1, the Association Request frame carries the STA side information of link1 and carries the STA side information of link2. The Association Request frame can carry a Multi-link Element, which is used to carry the information of the MLD and the information of the stations in the MLD. The AP MLD sends an Association Response frame on link1, the Association Response frame carries the AP side information of link1, and also carries the AP side information of link2, so as to realize the association establishment of STA1” and STA2” of the Non-AP MLD with AP1 and AP2 of the AP MLD respectively.

[0110] Before the multi-link establishment, the STA can discover the existence of the AP through the scanning form of active scanning or passive scanning, so as to associate with the AP to establish a connection, and then realize the establishment of the multi-link. Simply speaking, the purpose of the association establishment of the Non-AP MLD with the AP MLD is to establish one or more links (such as the link1 and link2 in the above FIG. 3) for the communication between the Non-AP MLD and the AP MLD.

[0111] In the passive scanning process, the STA can receive the management frame (such as the Beacon frame or the broadcasted Probe Response frame) sent by the AP on the channel. For example, the STA can jump to search the Beacon frame sent by the AP on different channels, and once the STA obtains the management information of the AP through the Beacon frame, the STA can further communicate with the AP through the Probe Request frame or the Probe Request frame to obtain other information in the AP.

[0112] In the active scanning process, the STA can actively broadcast a probe request frame without monitoring a beacon frame. If the AP receives the probe request frame and meets certain conditions (the conditions are not limited in the embodiments of the present application), the AP can initiate random channel access to reply to the probe response frame.

[0113] To assist the STA in fast scanning, the AP can carry a reduced neighbor report element (RNR element) in the beacon frame or the probe response frame to report the relevant information of the corresponding AP. In this way, the STA can obtain the information of the neighbor APs during scanning, select a suitable AP for association, and avoid the STA from constantly scanning the channel, thereby reducing the scanning time of the STA. According to 802.11be, a certain subordinate AP needs to carry the relevant information of other subordinate APs belonging to the same AP MLD through the reduced neighbor report element. Among them, the neighbor AP refers to the neighbor AP of the STA for the STA, and the neighbor AP refers to the neighbor AP of the AP for the AP.

[0114] It can be understood that the embodiments of the present application can be applied to various seamless roaming architectures, such as an enhanced fast basic service set (basic service set, BSS) switching (fast BSS transition, FT) architecture, a roaming AP MLD architecture, and the like. Among them, the enhanced FT is improved from the FT protocol, and by introducing context transfer (also referred to as context information transfer), the process of re-association of the non-AP MLD and the target AP MLD can be shortened, which helps to enhance the continuity of data transmission. In addition, since it is extended to the case of multi-link, the enhanced FT can also include the advance setting of the multi-link between the non-AP MLD and the target AP MLD. The roaming AP MLD architecture is an extension on the concept of AP MLD. In the roaming AP MLD architecture, two or more AP MLDs can logically belong to the same larger roaming AP MLD, so that even if the non-AP MLD switches from the current AP MLD to the target AP MLD, it is still logically associated with the same roaming AP MLD, and the only difference is that the link between the non-AP MLD and the roaming AP MLD has changed. Therefore, the process of roaming is equivalent to the process of link reconfiguration, which deletes the link with the current AP MLD and adds the link with the target AP MLD. This architecture also uses the context transfer method to shorten the link reconfiguration time and enhance the continuity of data transmission.

[0115] The embodiments of the present application mainly take the network deployed by IEEE 802.11 as an example for description, and those skilled in the art can easily understand that various aspects involved in the present application can be extended to other networks using various standards or protocols, for example, bluetooth, high performance radio LAN (HIPERLAN) and wide area network (WAN), WLAN, personal area network (PAN) or other now known or later developed networks. Therefore, regardless of the coverage range and wireless access protocol used, various aspects provided by the present application can be applied to any suitable wireless network.

[0116] One important protocol to help achieve fast roaming in the existing WiFi standards is the FT protocol, which is proposed by 802.11r. The FT protocol defines a mobility domain, which can include multiple BSSs. With the support of the FT protocol, a STA can quickly switch between BSSs under the same mobility domain. To achieve fast switching, the FT supports the STA to perform early pairwise transient key (PTK) negotiation with a target AP MLD, and allows the STA to perform early resource request, which greatly shortens the process of the STA establishing reassociation with the target AP, thereby achieving fast switching.

[0117] The main goal of IEEE 802.11bn is to achieve ultra high reliability, which includes reducing data loss and latency, and improving data transmission continuity. Although the FT protocol effectively speeds up roaming, in order to achieve seamless roaming, 802.11bn is also seeking a method to achieve faster switching and better maintain data transmission continuity.

[0118] In the current 802.11bn standard proposal, there is a preliminary consensus on context transfer. Context transfer will be used to enhance data transmission continuity and speed up roaming in the process of seamless roaming. Specifically, in the process of non-AP MLD roaming from the current AP MLD to the target AP MLD, the context of the non-AP MLD can be transferred to the target AP MLD, so that the context of the non-AP MLD data exchange can be saved (or retained or maintained). In addition, the context of the non-AP MLD can also be negotiated in advance with the target AP MLD. However, considering the phenomenon of ping-pong roaming, the non-AP MLD can roam between several AP MLDs multiple times, such as repeatedly roaming between AP MLD 1 and AP MLD 2. Although the transfer or early negotiation of the context can speed up the roaming of the non-AP MLD, since the non-AP MLD has to repeat such a process every time it roams, it will bring more additional overhead.

[0119] In view of this, the present application provides a communication method to effectively reduce the additional overhead caused by repeated roaming of the non-AP MLD.

[0120] The specific implementation of the communication method in the embodiments of the present application will be described in detail below with reference to the accompanying drawings. It can be understood that the methods or steps performed by the first access point multi-link device in each of the following embodiments can also be performed by a module (such as a processor, a processing unit, a chip system, a circuit or a chip, etc.) in the first access point multi-link device, or can also be implemented by a logic node, a logic module or software that can implement all or part of the functions of the first access point multi-link device. The methods or steps performed by the second access point multi-link device in each of the following embodiments can also be performed by a module (such as a processor, a processing unit, a chip system, a circuit or a chip, etc.) in the second access point multi-link device, or can also be implemented by a logic node, a logic module or software that can implement all or part of the functions of the second access point multi-link device. The methods or steps performed by the station multi-link device in each of the following embodiments can also be performed by a module (such as a processor, a processing unit, a chip system, a circuit or a chip, etc.) in the station multi-link device, or can also be implemented by a logic node, a logic module or software that can implement all or part of the functions of the station multi-link device.

[0121] FIG. 4 is a flow diagram of a communication method provided by an embodiment of the present application. The method is applicable to the network architecture shown in FIG. 1, and can also be applicable to the roaming scenarios shown in FIG. 2a or FIG. 2b. For the convenience of description, the communication method shown in FIG. 4 performed by the first access point multi-link device will be taken as an example for description below. For example, taking the roaming scenario shown in FIG. 2a as an example, the first access point multi-link device can be the current AP MLD shown in FIG. 2a, the second access point multi-link device can be the target AP MLD shown in FIG. 2a, and the station multi-link device can be the Non-AP MLD shown in FIG. 2a. For example, taking the roaming scenario shown in FIG. 2b as an example, the first access point multi-link device can be the AP MLD1 shown in FIG. 2b, the second access point multi-link device can be the AP MLD2 shown in FIG. 2b, and the station multi-link device can be the Non-AP MLD shown in FIG. 2b.

[0122] As shown in FIG. 4, the method comprises:

[0123] Step 401: The first access point multi-link device determines that the station multi-link device roams from the first access point multi-link device to the second access point multi-link device.

[0124] In the embodiments of the present application, if the station multi-link device determines to roam from the first access point multi-link device to the second access point multi-link device, the station multi-link device can send a roaming request to the first access point multi-link device or the second access point multi-link device. For example, when the signal quality between the station multi-link device and the first access point multi-link device is lower than a signal quality threshold, the station multi-link device wants to roam to an access point multi-link device (such as the second access point multi-link device) with better signal quality, and the station multi-link device can send a roaming request to the first access point multi-link device or the second access point multi-link device.

[0125] After receiving the roaming request from the station multi-link device, the first access point multi-link device or the second access point multi-link device can perform a roaming operation. The roaming request is used to request roaming from the first access point multi-link device to the second access point multi-link device (or roaming from the first access point multi-link device to the second access point multi-link device). When the first access point multi-link device senses (or knows) that the roaming operation is completed, the first access point multi-link device can send a roaming response to the station multi-link device, or when the second access point multi-link device senses (or knows) that the roaming operation is completed, the second access point multi-link device can send a roaming response to the station multi-link device.

[0126] The following is an example of the first access point multi-link device determining that the station multi-link device roams from the first access point multi-link device to the second access point multi-link device. For example, the second access point multi-link device can send indication information c to the first access point multi-link device when it is ready to perform data transmission with the station multi-link device, or after receiving the transferred context information. The first access point multi-link device can determine that the station multi-link device roams from the first access point multi-link device to the second access point multi-link device according to the indication information c after receiving the indication information c from the second access point multi-link device. The indication information c is used to indicate that the second access point multi-link device is ready to perform data transmission with the station multi-link device, or the indication information c is used to indicate that the second access point multi-link device has received the transferred context information. Alternatively, the second access point multi-link device can also send the indication information c to the first access point multi-link device when it senses that the switching operation (or roaming operation) of the station multi-link device is completed.

[0127] It can be understood that the first access point multi-link device can also determine that the station multi-link device roams from the first access point multi-link device to the second access point multi-link device by other means, which is not limited in the embodiments of the present application.

[0128] Step 402: The first access point multi-link device saves the first context information of the station multi-link device within a first time length.

[0129] For example, the first time length can be used to represent a time length for saving (or preserving) the context information when (or after) the roaming of the station multi-link device is completed. For example, the first time length can also be referred to as a context information save timeout value or a context information preserve timeout value. Alternatively, in some embodiments, the first time length can also be alternatively described as a "valid period (or time length) of saving of the context information". Alternatively, in some embodiments, the first time length can also be alternatively described as a "cut-off time (which can also be referred to as an expiration time) of saving of the context information".

[0130] In one example, the first time length can be a preset (or pre-defined or pre-configured) context information save time length, which can be determined according to an actual business scenario or an actual roaming situation of the station multi-link device.

[0131] In the embodiments of the present application, when the first time length is a preset context information save time length, the first access point multi-link device can determine that the preset context information save time length is the first time length. For example, the first access point multi-link device can determine a cut-off time of saving of the context information according to the first time length.

[0132] In another example, the first time length can be a roaming cut-off time length (or a re-association cut-off time length), such as a roaming cut-off time length (or a re-association cut-off time length) that can be defined by a protocol. That is, the first access point multi-link device can take the roaming cut-off time length (which can also be referred to as a roaming cut-off time interval, or can be understood as a time length before a roaming cut-off time) as the first time length.

[0133] In the embodiments of the present application, when the first time length is a roaming cut-off time length (or a re-association cut-off time length), the first access point multi-link device can determine that the roaming cut-off time length (or the re-association cut-off time length) is the first time length. For example, the first access point multi-link device can determine a cut-off time of saving of the context information according to the first time length.

[0134] It can be understood that there is already a reassociation deadline time in the existing standard, which stipulates the valid time for the station multi-link device (such as a Non-AP MLD or a STA) in the FT to perform PTK re-negotiation and resource request in advance, and the station multi-link device needs to send a reassociation request within the stipulated reassociation deadline time (which can also be referred to as a reassociation deadline time interval, or can be understood as a time interval before the reassociation deadline time). In other words, the reassociation deadline time is equivalent to a timeout value for reserving resources in advance for the roaming of the station multi-link device. Under the seamless roaming architecture, the concept of the reassociation deadline time can also be extended to the roaming deadline time.

[0135] Considering that the access point multi-link device reserves the context information is actually to reserve resources in advance for the next round of roaming of the station multi-link device, the first access point multi-link device can take the roaming deadline time or the reassociation deadline time as the first time length. In this way, the method can realize multiplexing of the existing roaming deadline time or reassociation deadline time without the need for reconfiguration or redefinition.

[0136] It should be understood that the context information mainly refers to information related to data exchange between the station multi-link device and the access point multi-link device. For example, the context information can be divided into semi-static context information and dynamic context information.

[0137] The semi-static context is not updated too frequently once negotiation is completed. For example, the semi-static context can include, but is not limited to, at least one of the following: pairwise transient key, block acknowledgement (BA), stream classification service (SCS), mirrored stream classification service (MSCS), target wake time (TWT), traffic identifier (TID) and TID-to-link mapping (TTLM), emergency preparedness communications service (EPCS). For example, the block acknowledgement can include, but is not limited to, the following: traffic identifier, BA policy, buffer size, or BA timeout, etc. The dynamic context is updated in time with data transmission, such as sequence number (SN) related information.

[0138] It can be understood that the semi-static context can be transferred during roaming or before roaming, and the dynamic context can only be transferred during roaming because it is updated in time.

[0139] Optionally, the first access point multi-link device can send third information to the station multi-link device after obtaining the first time length. Then, the station multi-link device can receive the third information from the first access point multi-link device. The third information can be used to indicate the first time length, or the third information can be used to indicate the timeout time. By sending the third information to the station multi-link device, the station multi-link device can learn the time length (or the expiration time) of the context information related to the station multi-link device in time, so that the station multi-link device can learn that the context information saved by the first access point multi-link device can only be reused (or used) when roaming back to the first access point multi-link device within the first time length.

[0140] For example, the first time length (or the timeout time) can be included in (or carried in or carried by) a timeout interval element (TIE), and the TIE can be carried in the third information.

[0141] Exemplarily, the third information can be one of the following: a beacon frame, a probe response frame, an association response frame, and a reassociation response frame.

[0142] Optionally, the timeout interval element can be sent by the first access point multi-link device to the station multi-link device in a process of associating the station multi-link device with the first access point multi-link device. For example, the timeout interval element can be carried in a beacon frame (or a probe response frame or an association response frame or a reassociation response frame), or can also be carried in a 4-way handshake of an association process.

[0143] Exemplarily, the structure of the timeout interval element can refer to FIG. 5. As shown in FIG. 5, the timeout interval element can include an element ID, a length, a timeout interval type, and a timeout interval value. In the embodiment of the present application, a new type is defined by using a reserved timeout interval type, and the corresponding timeout interval value is the first time length (or timeout time). For example, when timeout interval type = 7, the meaning of timeout interval value is defined as the first time length (or timeout time).

[0144] It can be understood that when the first time length is the roaming cutoff time length or the reassociation cutoff time length, the existing roaming cutoff time length or reassociation cutoff time length can be directly reused. In this case, the first time length is defined based on the protocol, and the first access point multi-link device and the station multi-link device have already learned the first time length in advance, so the first access point multi-link device does not need to send the third information to the station multi-link device, which can achieve the need to provide the first time length to the station multi-link device without extra, and helps to save communication overhead.

[0145] In the embodiment of the present application, when it is determined that the station multi-link device roams from the first access point multi-link device to the second access point multi-link device (or after it is determined that the station multi-link device roams from the first access point multi-link device to the second access point multi-link device), the first access point multi-link device can save the first context information of the station multi-link device (which can be understood as the first context information associated with the station multi-link device) within the first time length. In addition, the first access point multi-link device deletes the first context information of the station multi-link device after the first time length.

[0146] For example, the first context information can include, but is not limited to, at least one of the following: pairwise transient key, block acknowledgement, flow classification service, mirror flow classification service, target wake time, traffic identifier and link mapping, emergency preparedness communication service. Among these information, the information important for the continuity of data transmission of the station multi-link device includes the pairwise transient key, the block acknowledgement, the flow classification service and the target wake time. Therefore, the first access point multi-link device saving the context information helps to maintain the continuity of data transmission of the station multi-link device, and can help to reduce the latency or data loss caused by roaming. The first access point multi-link device saving the context information can also reduce (or reduce) the additional overhead caused by multiple context transfers between the first access point multi-link device and the second access point multi-link device or multiple context renegotiations between the first access point multi-link device and the second access point multi-link device.

[0147] It can be understood that the first context information can refer to semi-static context.

[0148] For example, taking the station multi-link device as Non-AP MLD, the first access point multi-link device as AP MLD1, and the second access point multi-link device as AP MLD2 as an example. In the case of ping-pong roaming, when the Non-AP MLD roams from the AP MLD1 to the AP MLD2, if it needs to roam back to the AP MLD1 within a first time period, the context saved at the AP MLD1 can be reused, so as to avoid the additional overhead caused by context transfer or context renegotiation. Alternatively, when the Non-AP MLD roams back to the AP MLD1 from the AP MLD2, the Non-AP MLD can carry information in the roaming request (or roaming request frame) for indicating that the saved context information does not need to be transferred. It should be understood that if the dynamic context information needs to be transferred, the Non-AP MLD can carry information in the roaming request (or roaming request frame) for indicating that the dynamic context information needs to be transferred.

[0149] It should be understood that when the Non-AP MLD roams back to the AP MLD1 from the AP MLD2, based on the data transmission between the Non-AP MLD and the AP MLD1, the context information related thereto can be normally updated according to the existing rules.

[0150] Similarly, in subsequent ping-pong roaming, if the non-AP MLD needs to roam back to the AP MLD2 within the first time length, the context saved at the AP MLD2 can also be reused, so as to avoid the additional overhead caused by context transfer or context re-negotiation. Optionally, when the non-AP MLD roams back to the AP MLD2 from the AP MLD1, the non-AP MLD can carry information indicating that the transfer of the saved context information is not needed in the roaming request. It should be understood that if the dynamic context information needs to be transferred, the non-AP MLD can carry information indicating that the transfer of the dynamic context information is needed in the roaming request.

[0151] It should be understood that after the non-AP MLD roams back to the AP MLD2 from the AP MLD1, based on the data transmission between the non-AP MLD and the AP MLD2, the context information related thereto can be normally updated according to the existing rules.

[0152] The implementation process of the first access point multi-link device saving the first context information of the station multi-link device within the first time length is introduced below through the following possible implementation manners.

[0153] Manner A1: The first access point multi-link device can start a timer when (or after) receiving the first roaming request (also referred to as the first roaming request frame) from the station multi-link device. The timer has a timing duration of the first time length, and the first roaming request is used to request roaming to a second access point multi-link device by the first access point multi-link device. For example, the first access point multi-link device can save the first context information when the timer has not timed out. That is to say, if the first access point multi-link device can save the first context information until the timer times out. For another example, the first access point multi-link device can delete the first context information when the timer times out. That is to say, if the first access point multi-link device can delete the first context information when (or after) the timer times out.

[0154] The manner A1 can make the time interval between the two roaming requests (i.e., the first roaming request and the second roaming request (also referred to as the second roaming request frame) for roaming back to the first access point multi-link device) not exceed the first time length, so as to reuse the first context information saved by the first access point multi-link device. The second roaming request is a roaming request located after the first roaming request, and is used to request roaming back to the first access point multi-link device. Optionally, when the station multi-link device sends the second roaming request to the second access point multi-link device, the station multi-link device can carry an indication information in the second roaming request, which is used to indicate that context information transfer is not needed, so as to avoid the additional overhead caused by context information transfer.

[0155] The manner A2 is that the first access point multi-link device can start a timer when (or after) sending the first roaming response (also referred to as the first roaming response frame) to the station multi-link device. The timer has a timing duration of the first time length. The first roaming request corresponds to (or maps to or is associated with) the first roaming response. That is, the first roaming response is a response to the first roaming request. For example, the first access point multi-link device can save the first context information when the timer has not timed out. That is, the first access point multi-link device can save the first context information until the timer times out. For another example, the first access point multi-link device can delete the first context information when the timer times out. That is, the first access point multi-link device can delete the first context information when (or after) the timer times out.

[0156] The manner A2 can make the time interval between the last roaming response and the next roaming request (i.e., the first roaming response and the second roaming request for roaming back to the first access point multi-link device) not exceed the first time length, so as to reuse the first context information saved by the first access point multi-link device.

[0157] For example, if the station multi-link device initiates a roaming request before (or when) the timer times out, the roaming request is used to request roaming from the second access point multi-link device to the first access point multi-link device (it can be understood that the roaming request is used to request roaming back to the second access point multi-link device), the first context information can be reused. If the station multi-link device initiates a roaming request after (or when) the timer times out, the roaming request is used to request roaming from the second access point multi-link device to the first access point multi-link device, the first context information cannot be reused (the first context information has been deleted), and the station multi-link device can perform roaming according to the existing roaming process.

[0158] It can be understood that, for the roaming request and the roaming response, there can be different names according to different seamless roaming architectures. For example, in the enhanced FT architecture, the roaming request can be a reassociation request, and the roaming response can be a reassociation response. For another example, in the roaming AP MLD architecture, the roaming request can be a link reconfiguration request, and the roaming response can be a link reconfiguration response.

[0159] In the embodiments of the present application, the context information saved after each time the station multi-link device roams away from a certain access point multi-link device is independent. That is to say, after each time the station multi-link device roams away from a certain access point multi-link device, the first time length for saving the context information corresponding to each roaming is re-timed. For example, continuing to take the station multi-link device as the Non-AP MLD, the first access point multi-link device as the AP MLD1, and the second access point multi-link device as the AP MLD2. If there is a roaming request 1, the roaming request 1 or the roaming response 1 can trigger the timer at the AP MLD1 to start timing. Among them, the roaming request 1 is used to request roaming from the AP MLD1 to the AP MLD2, and the roaming response 1 is a response to the roaming request 1. If there is a roaming request 2, the roaming request 2 or the roaming response 2 can trigger the timer at the AP MLD2 to start timing. Among them, the roaming request 2 is used to request roaming from the AP MLD2 to the AP MLD1, and the roaming response 2 is a response to the roaming request 2. If there is a roaming request 3, the roaming request 3 or the roaming response 3 can trigger the timer at the AP MLD1 to start timing. Among them, the roaming request 3 is used to request roaming from the AP MLD1 to the AP MLD2, and the roaming response 3 is a response to the roaming request 3.

[0160] Through the above steps 401 to 402, it can be seen that, compared with the existing roaming scheme, after the station multi-link device completes roaming, the context information related to the station multi-link device is directly deleted, and the first access point multi-link device saves the context information of the station multi-link device for a period of time (such as the first time length) after completing roaming, instead of deleting the context information immediately after the station multi-link device completes roaming. Therefore, the additional overhead caused by repeated roaming of the station multi-link device can be effectively reduced, such as the additional overhead caused by repeated context transfer or context re-negotiation in the roaming scenario.

[0161] It can be understood that, considering that saving context information needs to occupy the resources of the first access point multi-link device, the first access point multi-link device can not want to support this capability. In addition, since the resources occupied by saving different context information can also be different, even if the first access point multi-link device supports this capability, it can only support saving specific context information, such as pairwise transient key, block acknowledgement, flow classification service, and target wake-up time. Based on this, before the first access point multi-link device performs the saving operation of the first context information, the first access point multi-link device can interact with the station multi-link device for capability information (which can also be referred to as context information saving capability interaction). For details, refer to the communication method shown in FIG. 6.

[0162] For the convenience of description, the communication method shown in FIG. 6 is introduced below by taking the first access point multi-link device and the station multi-link device as the execution subject of the interaction illustration, but the application does not limit the execution subject of the interaction illustration.

[0163] As shown in FIG. 6, the method comprises:

[0164] Step 601: The first access point multi-link device sends first information to the station multi-link device. Correspondingly, the station multi-link device receives the first information from the first access point multi-link device.

[0165] The first information is used to indicate support for saving context information (context preserve), or the first information is used to indicate support for saving second context information (it can be understood that which context information is supported). The second context information can include the first context information, or the first information can be used to indicate that the first access point multi-link device supports saving context information within a first time length. For example, the second context information can include at least one of the following: pairwise transient key, block acknowledgement, flow classification service, mirror flow classification service, target wake-up time, traffic identifier and link mapping, emergency preparation communication service.

[0166] Optionally, the first information can also be used to indicate that saving context information is not supported.

[0167] For example, the first information can be carried in one of the following: a beacon frame, a probe response frame, an association response frame, and a re-association response frame.

[0168] Exemplarily, the following describes the indication of whether the first information supports saving context information through the following possible examples.

[0169] Example 1: Whether to support saving context information can be indicated by a corresponding change (such as content change or format change or length change or field change, etc.) of the first information.

[0170] Example 2: Whether to support saving context information can be implemented by the first information occupying (or using) 1 bit to indicate the corresponding content.

[0171] For example, when the bit value of the first information is 1, the first information can be used to indicate that saving context information is supported, at which time it can be defaulted that all context information of the station multi-link device can be saved. When the bit value of the first information is 0, the first information can be used to indicate that saving context information is not supported.

[0172] Example 3: Whether to support saving context information can be implemented by the type of the first information to indicate the corresponding content.

[0173] For example, when the type of the first information is type a1, it indicates that saving context information is supported. When the type of the first information is type a2, it indicates that saving context information is not supported.

[0174] Optionally, when the first information indicates that the second context information to be saved is supported, the first information can include the identification (or number or index or name) of the second context information to be saved.

[0175] For example, the following introduces the indication of the first information indicating which context information to be saved by the following possible examples.

[0176] Example 1': The first information includes a bitmap. Each bit of the bitmap corresponds to a context information. That is, the bitmap can be used to indicate which context information can be saved and which context information is not saved.

[0177] For example, the bitmap can include t bits. Each bit of the t bits corresponds to a context information (which can be understood as each bit corresponds to the identification (or number or index or name) of a context information). For example, taking a certain bit (such as the first bit) of the t bits as an example. The first bit corresponds to the context information p1, and the first bit can be used to indicate that the context information p1 is saved or the first bit can be used to indicate that the context information p1 is not saved. For example, taking the bit value of the bit as 1 or 0 as an example. When the bit value of the bit is 1, it means that the context information corresponding to the bit can be supported to be saved. When the bit value of the bit is 0, it means that the context information corresponding to the bit is not supported to be saved.

[0178] Example 2': The first information includes level information. The level information includes a certain level. It should be understood that different levels correspond to different context information storage ranges. That is, one level corresponds to one context information storage range. For example, the context information storage range can include the identification of the supported context information.

[0179] Considering the importance of different context information and the resources required to save the context information, the context information storage capability can be divided into different levels or context information storage levels, and the higher the level, the wider the corresponding context information range (or context information storage range). The first access point multi-link device can indicate the maximum level (or maximum context information storage level) supported.

[0180] As an example, the level division of the context information storage capability is as follows:

[0181] Level 0, indicating that it does not support saving context information;

[0182] Level 1, indicating that it supports saving pair-wise transient keys;

[0183] Level 2, indicating that it supports saving pair-wise transient keys and block acknowledgments;

[0184] Level 3, indicating that it supports saving all semi-static context information (such as pair-wise transient keys, block acknowledgments, flow classification services, mirror flow classification services, and target wake-up time).

[0185] Step 602: The station multi-link device sends second information to the first access point multi-link device. Accordingly, the first access point multi-link device receives the second information from the station multi-link device.

[0186] The second information can be used to indicate saving the context information of the station multi-link device, or the second information can be used to indicate the identification (or number or index or name) of the first context information (it can be understood that which context information is saved).

[0187] Alternatively, in some embodiments, the second information can be used to indicate saving the context information of the station multi-link device, which can be described as "the second information can be used to indicate saving the context information".

[0188] For example, the second information can be carried in a roaming request (such as the first roaming request). Alternatively, the station multi-link device can also send the second information to the first access point multi-link device before sending the first roaming request to the first access point multi-link device.

[0189] It can be understood that even if the first access point multi-link device (such as the current AP MLD) supports saving context information, the station multi-link device (such as the Non-AP MLD) does not necessarily have the need to save context information every time it roams. For example, in some roaming scenarios, when the station multi-link device initiates a roaming request, the connection quality (or signal quality) between the station multi-link device and the first access point multi-link device has been significantly reduced, which can be manifested in that the receive signal strength indicator (RSSI) of the first access point multi-link device is very poor. At this time, the connection quality between the station multi-link device and the second access point multi-link device (such as the target AP MLD) is obviously better than that between the station multi-link device and the first access point multi-link device, and the possibility of ping-pong roaming is small. Therefore, even if the first access point multi-link device saves context information, since the station multi-link device is not likely to roam back, the context information saving does not bring significant gain, but wastes the resources of the first access point multi-link device. Considering this scenario, since the station multi-link device can accurately measure the connection quality (such as comparing the RSSI) with the first access point multi-link device and the second access point multi-link device, the station multi-link device can decide whether to save context information, so as to explicitly inform the first access point multi-link device whether context information saving is needed after this roaming is completed, so as to avoid wasting the resources of the first access point multi-link device. For example, the station multi-link device can send indication information to the first access point multi-link device to indicate whether to save context information. When the station multi-link device determines that it will not roam back to the first access point multi-link device according to the actual situation (such as the RSSI of the second access point multi-link device being greater than the RSSI of the first access point multi-link device), it can send indication information to the first access point multi-link device not to save context information, so that the first access point multi-link device learns in time not to save context information, which helps to avoid wasting the resources of the first access point multi-link device.

[0190] Optionally, in the case that the first information indicates that saving context information is supported, or the first information indicates that the second context information that is supported is saved, the station multi-link device can determine whether to indicate to the first access point multi-link device whether to save context information according to the actual situation. For example, taking the case that the station multi-link device uses 1 bit indication information to indicate whether to save context information as an example. When the bit value of the 1 bit indication information is 1, it indicates to save context information. When the bit value of the 1 bit indication information is 0, it indicates not to save context information. Optionally, in the case that the first access point multi-link device needs to save context information, the station multi-link device can also indicate to the first access point multi-link device which context information to save (which can be understood as the range of context information to be saved).

[0191] For example, taking the first information indicating support for saving context information as an example. In the case where the first information indicates support for saving context information, if the station multi-link device expects that it may roam back to the first access point multi-link device within the first time length, the station multi-link device can send the second information described above to the first access point multi-link device.

[0192] In one example, if the second information is used to indicate saving the context information of the station multi-link device, the station multi-link device can use the second information (such as 1 bit indication information) to indicate whether to save the context information. For example, taking the second information as 1 bit indication information as an example. When the bit value of the 1 bit indication information is 1, it indicates saving the context information. When the bit value of the 1 bit indication information is 0, it indicates not saving the context information.

[0193] In another example, if the second information is used to indicate which specific context information to save, the station multi-link device can use the second information (such as 1 bit indication information) to indicate saving the context information, and the saving range of the context information is all the context information that can be saved, or the station multi-link device can carry the identity of the saved context information in the second information. At this time, the saved context information indicated by the station multi-link device belongs to the context information that the first access point multi-link device must save.

[0194] For another example, taking the first information indicating support for saving which context information as an example. In the case where the first information indicates support for saving which context information, if the station multi-link device expects that it may roam back to the first access point multi-link device within the first time length, the station multi-link device can send the second information described above to the first access point multi-link device. For example, when the first information includes a bit map d1 (used to indicate support for saving which context information), the station multi-link device can carry a bit map d2 in the second information, and the bit map d2 is used to indicate which specific context information to save. Wherein, the range of the saved context information indicated by the bit map d2 is not greater than (which can be understood as less than or equal to) the range of the saved context information indicated by the bit map d1. For example, the bit map d1 indicates support for saving the pair temporary key, block acknowledgement, flow classification service, mirror flow classification service and target wake-up time, and the bit map d2 indicates saving the pair temporary key, block acknowledgement and flow classification service.

[0195] When the first information includes the level information f1 (used to indicate the level corresponding to the supported saved context information), the station multi-link device can carry the level information f2 in the second information, the level information f2 being used to indicate the level corresponding to the specific saved context information. The level corresponding to the specific saved context information indicated by the level information f2 is not greater than the level corresponding to the supported saved context information indicated by the level information f1. For example, the level information f1 indicates level 2, and the level information f2 indicates level 1. The level 2 is used to indicate that the pair temporary key and block confirmation is saved, and the level 1 is used to indicate that the pair temporary key is saved.

[0196] It can be seen from the above steps 601 to 602 that the first access point multi-link device and the station multi-link device perform context information saving capability interaction, and indicate whether to save the context information or indicate which specific context information to save, so that the context information saving can be better implemented, and resource waste caused by meaningless context information saving (or saving meaningless context information) can be avoided.

[0197] Based on the technical solution of the communication method shown in FIG. 4, the communication method shown in FIG. 4 is introduced in detail through the specific example shown in FIG. 7. In the specific example shown in FIG. 4, the station multi-link device is a Non-AP MLD, the first access point multi-link device is an AP MLD1, and the second access point multi-link device is an AP MLD2.

[0198] FIG. 7 is a flow diagram of another communication method provided by an embodiment of the present application. As shown in FIG. 7, the specific process of the method can include:

[0199] Step 701: The Non-AP MLD performs data transmission with the AP MLD1.

[0200] When the Non-AP MLD and the AP MLD1 are in an associated state, the Non-AP MLD can perform data transmission with the AP MLD1.

[0201] Step 702: Roaming preparation phase.

[0202] For example, when the connection quality between the non-AP MLD and the AP MLD 1 decreases, the non-AP MLD prepares to roam to the AP MLD2. In order to speed up the roaming speed, the non-AP MLD can prepare to roam to the AP MLD2 before sending the roaming request a, which can include pair temporary key renegotiation (PTK renegotiation) or pair temporary key sharing (PTK sharing), and transfer of other semi-static context information.

[0203] Optionally, when the roaming condition is met (such as the roaming preparation operation has been completed or the connection quality between the non-AP MLD and the AP MLD 1 has decreased to a certain extent), the Non-AP MLD can send a roaming request a to the AP MLD 1 to start roaming (or switching) from the AP MLD 1 to the AP MLD 2.

[0204] Step 703: The Non-AP MLD sends a roaming request a to the AP MLD 1. Correspondingly, the AP MLD 1 receives the roaming request a from the Non-AP MLD.

[0205] The roaming request a is used to request roaming from the AP MLD 1 to the AP MLD 2.

[0206] Optionally, the AP MLD 1 can perform context information saving capability interaction with the Non-AP MLD before receiving the roaming request a from the Non-AP MLD, or before performing data transmission with the Non-AP MLD. The specific implementation can refer to the communication method illustrated in FIG. 6 described above, which will not be described here.

[0207] Optionally, the Non-AP MLD can also send a roaming request a to the AP MLD 2. Correspondingly, the AP MLD 2 can receive the roaming request a from the Non-AP MLD.

[0208] Step 704: The AP MLD 1 performs context information transfer with the AP MLD 2.

[0209] Optionally, during the switching from the AP MLD 1 to the AP MLD 2, the context information transfer between the AP MLD 1 and the AP MLD 2 about the non-AP MLD can be performed, which can specifically include dynamic context information transfer and semi-static context information that is not transferred in the roaming preparation phase. After completing the switching from the AP MLD 1 to the AP MLD 2, the AP MLD 1 or the AP MLD 2 can send a roaming response a' to the Non-AP MLD.

[0210] Step 705: The AP MLD 1 sends a roaming response a' to the Non-AP MLD. Correspondingly, the Non-AP MLD receives the roaming response a' from the AP MLD 1.

[0211] The roaming response a' can be used to indicate that the roaming has been completed.

[0212] Optionally, the roaming response a' can also be sent by the AP MLD 2 to the Non-AP MLD. For example, if the AP MLD 2 receives the roaming request a from the Non-AP MLD, the AP MLD 2 can also send the roaming response a' to the Non-AP MLD. Accordingly, the Non-AP MLD can receive the roaming response a' from the AP MLD 2.

[0213] Optionally, the AP MLD 1 can perform the saving operation of the context information related to the Non-AP MLD when receiving the roaming request a, or sending the roaming response a' to the Non-AP MLD. The specific implementation can refer to the related description in the communication method shown in FIG. 4, which will not be repeated here.

[0214] In the embodiment of the present application, after receiving the roaming response a', the Non-AP MLD can know that the roaming is completed, and then can perform data transmission with the AP MLD 2.

[0215] Step 706: The Non-AP MLD performs data transmission with the AP MLD 2.

[0216] When the Non-AP MLD and the AP MLD 2 are in the associated state, the Non-AP MLD can perform data transmission with the AP MLD 2.

[0217] Step 707: The Non-AP MLD sends a roaming request b to the AP MLD 2. Accordingly, the AP MLD 2 receives the roaming request b from the Non-AP MLD.

[0218] The roaming request b is used to request roaming from the AP MLD 2 to the AP MLD 1. That is to say, the roaming request b is used to request roaming back to the AP MLD 1.

[0219] Optionally, the Non-AP MLD can also send the roaming request b to the AP MLD 1. Accordingly, the AP MLD 1 can receive the roaming request b from the Non-AP MLD.

[0220] It can be understood that since the AP MLD 1 still saves the context information related to the Non-AP MLD after the first roaming process (i.e., the roaming request a) is completed, and the Non-AP MLD requests to roam back to the AP MLD 1 within the first time period, the previously saved context information can be reused, thereby reducing the additional overhead caused by the roaming preparation stage (such as context information re-negotiation or context information transfer) of the second roaming (i.e., the roaming request b).

[0221] Step 708: The AP MLD 1 performs context information transfer with the AP MLD 2.

[0222] The step 708 is an optional step.

[0223] It can be understood that, in the handover process from the AP MLD 2 to the AP MLD 1, dynamic context information transfer can still be performed between the AP MLD 2 and the AP MLD 1, but compared with the case without context information saving, the context information that needs to be transferred or re-negotiated has been minimized. For example, if dynamic context information transfer needs to be performed between the AP MLD 2 and the AP MLD 1, the step 708 can be performed. If dynamic context information transfer does not need to be performed between the AP MLD 2 and the AP MLD 1, the step 708 does not need to be performed.

[0224] Step 709: The AP MLD 2 sends a roaming response b' to the Non-AP MLD. Correspondingly, the Non-AP MLD receives the roaming response b' from the AP MLD 2.

[0225] The roaming response b' can be used to indicate that the roaming has been completed.

[0226] Optionally, the roaming response b' can also be sent by the AP MLD 1 to the Non-AP MLD. For example, if the AP MLD 1 receives the roaming request b from the Non-AP MLD, the AP MLD 1 can also send the roaming response b' to the Non-AP MLD. Correspondingly, the Non-AP MLD can receive the roaming response b' from the AP MLD 1.

[0227] Optionally, the AP MLD 2 can perform the context information saving operation related to the Non-AP MLD when receiving the roaming request b, or when sending the roaming response b' to the Non-AP MLD. The specific implementation can be referred to the related description in the communication method shown in FIG. 4, which will not be described here.

[0228] In the embodiment of the present application, the Non-AP MLD can know that the roaming has been completed after receiving the roaming response b', and then can perform data transmission with the AP MLD 1.

[0229] Optionally, the AP MLD 2 can perform context information saving capability interaction with the Non-AP MLD before receiving the roaming request b from the Non-AP MLD, or before sending the roaming response b' to the Non-AP MLD. The specific implementation can be referred to the communication method shown in FIG. 6, which will not be described here.

[0230] Step 710: The Non-AP MLD performs data transmission with the AP MLD1.

[0231] When the Non-AP MLD is in an associated state with the AP MLD1, the Non-AP MLD can perform data transmission with the AP MLD1.

[0232] FIG. 8 is a flow diagram illustrating a communication method according to an embodiment of the present disclosure. The method is applicable to the network architecture shown in FIG. 1, and can also be applicable to the roaming scenario shown in FIG. 2a or FIG. 2b. For ease of description, the following describes an example in which a first access point multi-link device performs the communication method shown in FIG. 8. For example, in the roaming scenario shown in FIG. 2a, the first access point multi-link device can be the current AP MLD shown in FIG. 2a, the second access point multi-link device can be the target AP MLD shown in FIG. 2a, and the station multi-link device can be the Non-AP MLD shown in FIG. 2a. For example, in the roaming scenario shown in FIG. 2b, the first access point multi-link device can be the AP MLD1 shown in FIG. 2b, the second access point multi-link device can be the AP MLD2 shown in FIG. 2b, and the station multi-link device can be the Non-AP MLD shown in FIG. 2b.

[0233] As shown in FIG. 8, the method includes the following steps.

[0234] Step 801: The first access point multi-link device determines that a station multi-link device roams from the first access point multi-link device to a second access point multi-link device.

[0235] It can be understood that the implementation process of step 801 can refer to the implementation process of step 401 described above, which will not be described here again.

[0236] Step 802: The first access point multi-link device saves a setup link between the first access point multi-link device and the station multi-link device for a second time duration.

[0237] For example, the second time duration can be used to represent a time duration for saving the setup link between the first access point multi-link device and the station multi-link device when (or after) the station multi-link device completes roaming. It should be understood that the second time duration can be the same as the first time duration.

[0238] For example, the second time duration can also be referred to as a setup link save timeout value or a setup link reservation timeout value. Alternatively, in some embodiments, the second time duration can also be described as a “save validity period (or save time duration) of the setup link” or a “save expiration time (also referred to as save expiration time) of the setup link”.

[0239] In one example, the second time length can be a preset setting link preservation time length, which can be determined according to an actual business scenario or an actual roaming situation of the station multi-link device.

[0240] In the embodiment of the present application, when the second time length is the preset setting link preservation time length, the first access point multi-link device can determine that the preset setting link preservation time length is the second time length. For example, the first access point multi-link device can determine the preservation deadline of the setting link according to the second time length.

[0241] In another example, the second time length can be a roaming deadline (or a re-association deadline), which can be defined by a protocol. That is, the first access point multi-link device can take the roaming deadline (which can also be referred to as a roaming deadline interval, or can be understood as a time length before the roaming deadline) as the second time length.

[0242] In the embodiment of the present application, when the second time length is the roaming deadline (or the re-association deadline), the first access point multi-link device can determine that the roaming deadline (or the re-association deadline) is the second time length. For example, the first access point multi-link device can determine the preservation deadline of the setting link according to the second time length.

[0243] The related description about the roaming deadline (or the re-association deadline) can be referred to the related introduction in the above step 402, which will not be repeated here.

[0244] Optionally, after obtaining the second time length, the first access point multi-link device can send third information to the station multi-link device. Then, the station multi-link device can receive sixth information from the first access point multi-link device. The sixth information can be used to indicate the second time length, or the sixth information can be used to indicate the timeout time. By sending the sixth information to the station multi-link device, the method can facilitate the station multi-link device to timely learn the preservation time length (or the preservation expiration time) of the setting link (which can also be referred to as the already set link) between the first access point multi-link device and the station multi-link device, so that the station multi-link device can learn that only roaming back to the first access point multi-link device within the second time length can reuse (which can also be referred to as re-use or re-enable) the setting link between the first access point multi-link device and the station multi-link device.

[0245] For example, the second time length (or the timeout time) can be included in a timeout interval element, and the timeout interval element can be carried in the sixth information.

[0246] Exemplarily, the sixth information can be one of: a beacon frame, a probe response frame, an association response frame, and a re-association response frame.

[0247] Optionally, the timeout interval element can be sent by the first access point multi-link device to the station multi-link device in a process of associating the station multi-link device with the first access point multi-link device. For example, the timeout interval element can be carried in a beacon frame (or a probe response frame or an association response frame or a re-association response frame), or can also be carried in the 4-way handshake of the association process.

[0248] Exemplarily, the structure of the timeout interval element can continue to refer to FIG. 5, and the related description of FIG. 5 can refer to the related introduction of the above-mentioned FIG. 5 part, and only the “first duration” is replaced by “second duration”.

[0249] It can be understood that when the second duration is the roaming cutoff duration or the re-association cutoff duration, the existing roaming cutoff duration or re-association cutoff duration can be directly reused, and in this case, the second duration is defined based on the protocol, and the first access point multi-link device and the station multi-link device have already known the second duration in advance, so the first access point multi-link device does not need to send the sixth information to the station multi-link device, which can achieve the need to provide the second duration to the station multi-link device without extra, and helps to save communication overhead.

[0250] Next, taking the station multi-link device as a Non-AP MLD and the first access point multi-link device as an AP MLD1, the setting link is introduced.

[0251] In the (re)association process, the non-AP MLD can request the (re)setup link to the AP MLD1 through the (re)association request frame. If the AP MLD1 indicates in the (re)association response frame that it accepts the link (re)setup request, and these links are not removed (removed by the AP MLD1 to remove the AP belonging to it) or deleted (deleted by the link re-setup) in the subsequent, then these links are referred to as the setup link between the AP MLD1 and the non-AP MLD, such as the link 1 and the link 2 shown in FIG. 3.

[0252] For example, if there is at least one uplink or downlink traffic identifier mapped to a certain setup link, the usage state of the setup link is defined as enabled. If there is no uplink or downlink traffic identifier mapped to a certain setup link, the usage state of the setup link is defined as disabled.

[0253] In the embodiments of the present application, when or after the determination that the station multi-link device roams from the first access point multi-link device to the second access point multi-link device, the first access point multi-link device can save the setup link between the first access point multi-link device and the station multi-link device for a second time length. That is, the setup link between the first access point multi-link device and the station multi-link device is saved for the second time length. In addition, after the second time length, the first access point multi-link device deletes the setup link between the first access point multi-link device and the station multi-link device.

[0254] Optionally, the setup link can be related to the context information of the station multi-link device. In other words, if the first access point multi-link device saves the setup link between the first access point multi-link device and the station multi-link device, that is, saves some context information negotiated on the setup link (or can be understood as saves some context information that has been negotiated before). For example, some context information can include pairwise transient key, block acknowledgement, flow classification service and mirror flow classification service. Optionally, in addition to the above negotiated some context information, the first access point multi-link device can additionally indicate to the station multi-link device whether to support saving other context information, and the specific indication implementation process can refer to the related implementation of step 601, which will not be described here.

[0255] It can be understood that, since the station multi-link device has roamed to the second access point multi-link device, the setup link saved between the first access point multi-link device and the station multi-link device will not have any traffic identifier mapping. In addition, from the perspective of the first access point multi-link device, after the station multi-link device completes roaming, the setup link between the first access point multi-link device and the station multi-link device is disabled for a second time length, or in other words, the setup link between the first access point multi-link device and the station multi-link device is saved for a second time length, rather than being directly deleted. After that, the setup link between the first access point multi-link device and the station multi-link device is deleted after being saved for a second time length. However, the existing roaming scheme directly deletes the setup link between the first access point multi-link device and the station multi-link device after the station multi-link device completes roaming. Therefore, compared with the existing roaming scheme, the scheme provided by the embodiments of the present application can effectively avoid the need for the station multi-link device to re-add a link when roaming back to the first access point multi-link device, thereby effectively reducing the additional overhead caused by the need for the station multi-link device to re-add a link when roaming back to the first access point multi-link device, and also to a certain extent, the context information of the station multi-link device is saved, achieving the effect of saving context information, that is, the additional overhead caused by repeatedly transferring or re-negotiating context in the roaming scenario can be reduced.

[0256] For example, continue to take the station multi-link device as the Non-AP MLD, the first access point multi-link device as the AP MLD1, and the second access point multi-link device as the AP MLD2. The AP MLD1 includes the AP1-1 and the AP1-2, the AP MLD2 includes the AP2-1 and the AP2-2, and the non-AP MLD includes the STA1' and the STA2'. Please refer to FIG. 9, which is a schematic diagram of the link between the Non-AP MLD and the AP MLD provided by the embodiment of the present application. The links shown in FIG. 9 are all set links. When the Non-AP MLD roams from the AP MLD1 to the AP MLD2, the link between the Non-AP MLD and the AP MLD1 (represented by a black dashed line in FIG. 9) has no traffic identifier mapping, so the link between the Non-AP MLD and the AP MLD1 cannot be used for data transmission. The link between the Non-AP MLD and the AP MLD2 (represented by a black solid line in FIG. 9) has traffic identifier mapping, so the link between the Non-AP MLD and the AP MLD2 can be used for data transmission. When the Non-AP MLD roams from the AP MLD2 to the AP MLD1 (which can be understood as the Non-AP MLD roaming back to the AP MLD1), since the link between the Non-AP MLD and the AP MLD1 is reserved for a second time, the saved link between the Non-AP MLD and the AP MLD1 can be directly reused. It can be understood that the Non-AP MLD roams back to the AP MLD1 before the second time arrives.

[0257] The implementation process of the first access point multi-link device saving the set link between the first access point multi-link device and the station multi-link device within the second time is introduced below through the following possible implementation manners.

[0258] In an implementation B1, the first access point multi-link device can start a timer upon (or after) receiving the first roaming request from the station multi-link device. The timer has a second time duration. The first roaming request is for requesting to roam to the second access point multi-link device by the first access point multi-link device. For example, the first access point multi-link device can maintain the setup link between the first access point multi-link device and the station multi-link device when the timer is not expired. That is, the first access point multi-link device can maintain the setup link between the first access point multi-link device and the station multi-link device until the timer is expired. For another example, the first access point multi-link device can delete the setup link between the first access point multi-link device and the station multi-link device when the timer is expired. That is, the first access point multi-link device can delete the setup link between the first access point multi-link device and the station multi-link device when (or after) the timer is expired.

[0259] The above implementation B1 can make the time interval between two roaming requests (i.e., the first roaming request and a second roaming request for roaming back to the first access point multi-link device) not exceed the first time duration, so as to reuse the setup link between the first access point multi-link device and the station multi-link device which is maintained (or reserved). The second roaming request is one of the roaming requests after the first roaming request, and is for requesting to roam back to the first access point multi-link device.

[0260] In an implementation B2, the first access point multi-link device can start a timer upon (or after) sending the first roaming response to the station multi-link device. The timer has a second time duration. The first roaming request corresponds to the first roaming response. That is, the first roaming response is a response to the first roaming request. For example, the first access point multi-link device can maintain the setup link between the first access point multi-link device and the station multi-link device when the timer is not expired. That is, the first access point multi-link device can maintain the setup link between the first access point multi-link device and the station multi-link device until the timer is expired. For another example, the first access point multi-link device can delete the setup link between the first access point multi-link device and the station multi-link device when the timer is expired. That is, the first access point multi-link device can delete the setup link between the first access point multi-link device and the station multi-link device when (or after) the timer is expired.

[0261] The manner B2 can make the time interval between the last roaming response and the next roaming request (i.e., the first roaming response and the second roaming request for roaming back to the first access point multi-link device) not exceed the second time length, so that the saved setting link between the first access point multi-link device and the station multi-link device can be reused.

[0262] For example, if the station multi-link device initiates a roaming request before the timer expires (or before the timer has not expired), the roaming request is used to request roaming from the second access point multi-link device to the first access point multi-link device (it can be understood that the roaming request is used to request roaming back to the second access point multi-link device), the saved setting link between the first access point multi-link device and the station multi-link device can be reused. If the station multi-link device initiates a roaming request after the timer expires (or after the timer has expired), the roaming request is used to request roaming from the second access point multi-link device to the first access point multi-link device, the setting link between the first access point multi-link device and the station multi-link device cannot be reused (the saved setting link between the first access point multi-link device and the station multi-link device has been deleted), at this time the station multi-link device can perform roaming according to the existing roaming process.

[0263] In the embodiments of the present application, the setting link saved after the station multi-link device roams away from a certain access point multi-link device each time is independent. That is to say, after the station multi-link device roams away from a certain access point multi-link device each time, the second time length for saving the setting link corresponding to each roaming is restarted. For example, continue to take the station multi-link device as the Non-AP MLD, the first access point multi-link device as the AP MLD1, and the second access point multi-link device as the AP MLD2. If there is a roaming request 1, the roaming request 1 or the roaming response 1 can trigger the timer at the AP MLD1 to start timing. Among them, the roaming request 1 is used to request roaming from the AP MLD1 to the AP MLD2, and the roaming response 1 is a response to the roaming request 1. If there is a roaming request 2, the roaming request 2 or the roaming response 2 can trigger the timer at the AP MLD2 to start timing. Among them, the roaming request 2 is used to request roaming from the AP MLD2 to the AP MLD1, and the roaming response 2 is a response to the roaming request 2. If there is a roaming request 3, the roaming request 3 or the roaming response 3 can trigger the timer at the AP MLD1 to start timing. Among them, the roaming request 3 is used to request roaming from the AP MLD1 to the AP MLD2, and the roaming response 3 is a response to the roaming request 3.

[0264] It can be seen from the above steps 801 to 802 that, compared with the existing roaming scheme, after the station multi-link device completes roaming, the set link between the first access point multi-link device and the station multi-link device is directly deleted, and in the present method, after the station multi-link device completes roaming, the set link between the first access point multi-link device and the station multi-link device is saved for a period of time (such as a second time length), so that when the station multi-link device roams back to the first access point multi-link device within the first time length, the saved set link between the first access point multi-link device and the station multi-link device can be reused, thereby effectively avoiding the need for the station multi-link device to re-add a link when roaming back to the first access point multi-link device (it can be understood that there is no need to re-establish the link between the first access point multi-link device and the station multi-link device), thereby effectively reducing the additional overhead caused by the need for the station multi-link device to re-add a link when roaming back to the first access point multi-link device. In addition, based on the first access point multi-link device saving the set link between the first access point multi-link device and the station multi-link device for a period of time (such as a second time length) after the station multi-link device completes roaming, the context information of the station multi-link device is also saved to some extent, achieving the effect of saving context information, that is, the additional overhead caused by repeated context transfer or context renegotiation in the repeated roaming scenario can be reduced.

[0265] It can be understood that, considering that saving the set link between the first access point multi-link device and the station multi-link device requires occupying the resources of the first access point multi-link device, the first access point multi-link device can not want to support this capability. Based on this, before the first access point multi-link device performs the saving operation of the set link between the first access point multi-link device and the station multi-link device, the first access point multi-link device can interact with the station multi-link device for capability information (which can also be referred to as context information saving capability interaction). For details, refer to the communication method shown in FIG. 10.

[0266] For the convenience of description, the communication method shown in FIG. 10 is described below by taking the first access point multi-link device and the station multi-link device as an example of the execution subject of the interaction, but the present application is not limited to the execution subject of the interaction.

[0267] As shown in FIG. 10, the method comprises:

[0268] Step 1001: The first access point multi-link device sends fourth information to the station multi-link device. Correspondingly, the station multi-link device receives the fourth information from the first access point multi-link device.

[0269] The fourth information can be used to indicate that the set-up link is supported to be saved, or the fourth information can also be used to indicate that the set-up link is supported to be saved (which can be understood as indicating which set-up link is supported to be saved).

[0270] Optionally, the fourth information can also be used to indicate that the set-up link is not supported to be saved.

[0271] For example, the fourth information can be carried in one of the following: a beacon frame, a probe response frame, an association response frame, and a re-association response frame.

[0272] For example, the fourth information can be carried in one of the following: a beacon frame, a probe response frame, an association response frame, and a re-association response frame.

[0273] For example, the fourth information can be carried in one of the following: a beacon frame, a probe response frame, an association response frame, and a re-association response frame.

[0274] For example, the fourth information can be carried in one of the following: a beacon frame, a probe response frame, an association response frame, and a re-association response frame.

[0275] For example, when the bit value of the fourth information is 1, the fourth information can be used to indicate that the set-up link is supported to be saved, and at this time it can be defaulted that all set-up links between the first access point multi-link device and the station multi-link device can be saved. When the bit value of the fourth information is 0, the fourth information can be used to indicate that the set-up link is not supported to be saved.

[0276] For example, the fourth information can be carried in one of the following: a beacon frame, a probe response frame, an association response frame, and a re-association response frame.

[0277] For example, when the bit value of the fourth information is 1, the fourth information can be used to indicate that the set-up link is supported to be saved, and at this time it can be defaulted that all set-up links between the first access point multi-link device and the station multi-link device can be saved. When the bit value of the fourth information is 0, the fourth information can be used to indicate that the set-up link is not supported to be saved.

[0278] Optionally, when the fourth information can also be used to indicate that the set-up link is supported to be saved, the fourth information can include the identification (or number or index or name) of the set-up link supported to be saved, or the fourth information can be used to indicate that the first access point multi-link device supports saving the set-up link within a second time period.

[0279] Step 1002: The station multi-link device sends the fifth information to the first access point multi-link device. Correspondingly, the first access point multi-link device receives the fifth information from the station multi-link device.

[0280] The fifth information can be used to indicate to save the setup link between the first access point multi-link device and the station multi-link device, or the fifth information can be used to indicate the identity (or number or index or name) of the saved setup link (which can be understood as which setup link is saved).

[0281] Alternatively, in some embodiments, the fifth information can be used to indicate to save the setup link between the first access point multi-link device and the station multi-link device can be replaced by the description "the fifth information can be used to indicate to save the setup link".

[0282] It can be understood that if the setup link between the first access point multi-link device and the station multi-link device is saved, the first access point multi-link device and the station multi-link device need to jointly maintain the setup link within a second time length after the station multi-link device completes roaming.

[0283] For example, the fifth information can be carried in the roaming request (such as the first roaming request). Alternatively, the station multi-link device can also send the fifth information to the first access point multi-link device before sending the first roaming request to the first access point multi-link device.

[0284] It can be understood that even if the first access point multi-link device (such as the current AP MLD) supports saving the set link, the station multi-link device (such as the Non-AP MLD) does not necessarily have the need to save the set link every time it roams. For example, in some roaming scenarios, when the station multi-link device initiates a roaming request, the connection quality between the station multi-link device and the first access point multi-link device has been significantly reduced, which can be manifested in that the RSSI of the first access point multi-link device is very poor. At this time, the connection quality between the station multi-link device and the second access point multi-link device (such as the target AP MLD) is obviously better than the connection quality between the station multi-link device and the first access point multi-link device, and the possibility of ping-pong roaming is small. Therefore, even if the first access point multi-link device saves the set link, since the station multi-link device is not likely to roam back, saving the set link does not bring significant gains, but wastes the resources of the first access point multi-link device. Considering this scenario, since the station multi-link device can accurately measure the connection quality with the first access point multi-link device and the second access point multi-link device (such as comparing the RSSI of the two), the station multi-link device can decide whether to save the set link, so as to explicitly inform the first access point multi-link device whether to save the set link after this roaming is completed, so as to avoid wasting the resources of the first access point multi-link device. For example, the station multi-link device can send indication information to the first access point multi-link device, indicating whether to save the set link. When the station multi-link device determines that it will not roam back to the first access point multi-link device according to the actual situation (such as the RSSI of the second access point multi-link device being greater than the RSSI of the first access point multi-link device), it can send indication information to the first access point multi-link device not to save the set link, so that the first access point multi-link device can learn in time not to save the set link, which helps to avoid wasting the resources of the first access point multi-link device.

[0285] Optionally, in the case where the fourth information indicates that saving the set link is supported, if the station multi-link device predicts that it may roam back to the first access point multi-link device within the second time length, the station multi-link device can send the above-mentioned sixth information to the first access point multi-link device.

[0286] It can be seen from the above steps 1001 to 1002 that the first access point multi-link device and the station multi-link device perform set link saving capability interaction to indicate whether to save the set link, which can better achieve set link saving, can save the context information of the station multi-link device to some extent, achieve the effect of saving the context information, and can help to avoid meaningless resource waste caused by setting link saving.

[0287] FIG. 11 is a flow diagram illustrating a communication method according to an embodiment of the present application. The method is applicable to the network architecture shown in FIG. 1, and can also be applicable to the roaming scenarios shown in FIG. 2a or FIG. 2b. For ease of description, the first access point multi-link device or the second access point multi-link device and the station multi-link device are taken as an example of the interactive execution subject of the communication method shown in FIG. 11, but the present application is not limited to the interactive execution subject. For example, taking the roaming scenario shown in FIG. 2a as an example, the first access point multi-link device can be the current AP MLD shown in FIG. 2a, the second access point multi-link device can be the target AP MLD shown in FIG. 2a, and the station multi-link device can be the Non-AP MLD shown in FIG. 2a. For example, taking the roaming scenario shown in FIG. 2b as an example, the first access point multi-link device can be the AP MLD1 shown in FIG. 2b, the second access point multi-link device can be the AP MLD2 shown in FIG. 2b, and the station multi-link device can be the Non-AP MLD shown in FIG. 2b.

[0288] As shown in FIG. 11, the method includes the following steps.

[0289] Step 1101: The station multi-link device sends seventh information to the first access point multi-link device or the second access point multi-link device. Correspondingly, the first access point multi-link device or the second access point multi-link device receives the seventh information from the station multi-link device.

[0290] It can be understood that the station multi-link device can send the seventh information to the first access point multi-link device, or the station multi-link device can also send the seventh information to the second access point multi-link device, which is not limited by the present application.

[0291] The seventh information can be used to request roaming from the first access point multi-link device to the second access point multi-link device.

[0292] For example, the seventh information can be a certain roaming request (such as the first roaming request), or the seventh information can be request information carried in a certain roaming request (such as the first roaming request).

[0293] It can be understood that, due to some reasons (such as the capability of the first access point multi-link device is asymmetric with the capability of the second access point multi-link device), there can be a case that the second access point multi-link device does not accept the transferred context information. Based on this, considering that the context information transferred to the second access point multi-link device can not be accepted by the second access point multi-link device, the station multi-link device can not perform the context information transfer, but re-negotiate the context information with the second access point multi-link device after completing the roaming. Therefore, the station multi-link device can send indication information to the first access point multi-link device or the second access point multi-link device, the indication information being used to indicate whether the context information transfer is needed. For example, the station multi-link device can send ninth information to the first access point multi-link device or the second access point multi-link device. Then, the first access point multi-link device or the second access point multi-link device can receive the ninth information from the station multi-link device. The ninth information can be used to indicate whether the context information transfer is needed, or the ninth information can be used to indicate the identity of the context information that needs to be transferred. For example, the ninth information can be carried in the roaming request sent by the station multi-link device to the first access point multi-link device or the second access point multi-link device.

[0294] In one example, if the station multi-link device wants to perform the context information transfer, or the station multi-link device expects that some context information can be accepted by the second access point multi-link device, the ninth information sent by the station multi-link device to the first access point multi-link device or the second access point multi-link device is used to indicate that the context information transfer is needed, or the ninth information sent by the station multi-link device to the first access point multi-link device or the second access point multi-link device is used to indicate the identity of the context information that needs to be transferred.

[0295] It can be understood that, in the case that the ninth information indicates that the context information transfer is needed, the ninth information can carry the identity of the context information that needs to be transferred.

[0296] In another example, if the station multi-link device does not want to perform the context information transfer, or the station multi-link device expects that one or more context information can not be accepted by the second access point multi-link device, the ninth information sent by the station multi-link device to the first access point multi-link device or the second access point multi-link device is used to indicate that the context information transfer is not needed.

[0297] For example, taking the station multi-link device as the Non-AP MLD, the first access point multi-link device as the AP MLD1, and the second access point multi-link device as the AP MLD2, and taking the ninth information as an example which is carried in the roaming request. In some roaming scenarios, when the capability of the AP MLD1 is stronger (or greater) than the capability of the AP MLD2, the Non-AP MLD expects that even if some context information (such as flow classification service and target wake-up time) is transferred, it is not likely to be accepted by the AP MLD2, and therefore the Non-AP MLD can carry the ninth information in the roaming request to indicate that the transfer of these context information is not needed, which can effectively reduce (or lower or avoid) the additional overhead caused by the transfer of these context information.

[0298] For another example, continuing to take the station multi-link device as the Non-AP MLD, the first access point multi-link device as the AP MLD1, and the second access point multi-link device as the AP MLD2. After the Non-AP MLD roams from the AP MLD1 to the AP MLD2, it hopes to roam back to the AP MLD1 within a certain period of time (such as the first time length or the second time length). In this case, since the Non-AP MLD knows that the AP MLD1 still saves the context information related to the Non-AP MLD, the Non-AP MLD can carry the ninth information in the roaming request to roam back to the AP MLD1 to indicate that the context information transfer is not needed, which can effectively reduce the additional overhead caused by the context information transfer.

[0299] Step 1102: The first access point multi-link device or the second access point multi-link device sends the eighth information to the station multi-link device. Correspondingly, the station multi-link device receives the eighth information from the first access point multi-link device or the second access point multi-link device.

[0300] It can be understood that the eighth information received by the station multi-link device can come from the first access point multi-link device, or the eighth information received by the station multi-link device can also come from the second access point multi-link device, which is not limited in the present application.

[0301] The eighth information can be used to indicate the context information transfer result. The context information transfer result can include context information accepted by the second access point multi-link device and / or context information not accepted by the second access point multi-link device. Alternatively, the context information transfer result can include context information accepted by the second access point multi-link device and / or context information not accepted by the second access point multi-link device can be replaced by “the context information transfer result can include an identifier (or a number or an index or a name) of context information accepted by the second access point multi-link device and / or an identifier (or a number or an index or a name) of context information not accepted by the second access point multi-link device”.

[0302] For example, the eighth information can be a certain roaming response (such as a roaming response corresponding to the first roaming request), or the eighth information can also be indication information carried in a certain roaming response (such as a roaming response corresponding to the first roaming request).

[0303] For example, the context information can include at least one of the following: a pair of temporary keys, a block confirmation, a flow classification service, a mirror flow classification service, a target wake-up time, a traffic identifier and a link-to-link mapping, and an emergency preparation communication service.

[0304] Alternatively, if the context information transfer result includes context information not accepted by the second access point multi-link device, the eighth information can further include third context information recommended by the second access point multi-link device. The third context information corresponds to the context information not accepted by the second access point multi-link device. In this way, the station multi-link device can learn (or know) in time (or earlier) what kind of context information can be accepted by the second access point multi-link device, which helps the station multi-link device to re-negotiate with the second access point multi-link device in time, thereby effectively improving the re-negotiation efficiency (which can be understood as accelerating the re-negotiation speed).

[0305] For example, taking the eighth information carried in the roaming response as an example, the first access point multi-link device is an AP MLD1, the second access point multi-link device is an AP MLD2, and the station multi-link device is a Non-AP MLD. In order to inform the Non-AP MLD of the context information transfer result in the roaming process, the AP MLD2 (or the AP MLD1) can carry information (such as the eighth information) related to the context information transfer result in the roaming response. For example, if the context information transfer is performed and some of the transferred context information is not accepted by the AP MLD2, the AP MLD2 (or the AP MLD1) can carry the eighth information in the roaming response, and the eighth information is used to indicate the identity of the context information (which can be understood as specific context information that is not accepted by the AP MLD2) that is not accepted by the AP MLD2 and / or the identity of the context information (which can be understood as specific context information that is accepted by the AP MLD2) that is accepted by the AP MLD2. It can be understood that the context information that is not accepted by the AP MLD2 will be in a default state specified by a protocol after the roaming is completed, until the Non-AP MLD performs re-negotiation of the context information that is not accepted by the AP MLD2 with the AP MLD2. Alternatively, for the context information that is not accepted by the AP MLD2, the AP MLD2 can recommend (or suggest) corresponding context information (which can be understood as new context information corresponding to the context information that is not accepted by the AP MLD2) to the Non-AP MLD, such as that the AP MLD2 can carry the recommended context information in the roaming response, or the AP MLD2 can send the recommended context information to the AP MLD1, and the AP MLD1 carries the recommended context information of the AP MLD2 in the roaming response and sends it to the Non-AP MLD. Then, the Non-AP MLD can perform re-negotiation with the AP MLD2 according to the recommended context information of the AP MLD2 after completing the roaming. In this way, the Non-AP MLD can learn in a timely manner what kind of context information can be accepted by the AP MLD2, so as to effectively improve the re-negotiation efficiency.

[0306] For example, taking the target wake-up time that is not accepted by the AP MLD2 as an example. Based on the transferred target wake-up time not being accepted by the AP MLD2, the AP MLD2 (or the AP MLD1) can carry the identity of the target wake-up time and the target wake-up time element in the roaming response. The target wake-up time element can include the target wake-up time recommended by the AP MLD2 (which can be understood as new target wake-up time corresponding to the target wake-up time that is not accepted by the AP MLD2), such as that the target wake-up time that is not accepted by the AP MLD2 is t1, and the target wake-up time recommended by the AP MLD2 is t1'.

[0307] It can be understood that in the existing roaming scheme, the first access point multi-link device automatically transfers the context information related to the station multi-link device to the second access point multi-link device after receiving the roaming request from the station multi-link device. The station multi-link device defaults that the context information transfer is successful, or the transferred context information is all accepted by the second access point multi-link device. That is to say, the station multi-link device can continue to perform data transmission with the second access point multi-link device based on the previous context information after completing the roaming. However, due to some reasons (such as the asymmetric capabilities of the first access point multi-link device and the second access point multi-link device), there may be a case that the second access point multi-link device does not accept the transferred context information. When this case occurs, the station multi-link device usually needs to re-negotiate the context information that is not accepted by the second access point multi-link device, and the station multi-link device does not know this situation and mistakenly believes that the context information transferred to the second access point multi-link device has been accepted by the second access point multi-link device, which may cause a problem in the continuity of data transmission between the station multi-link device and the second access point multi-link device. To solve this problem, in the scheme provided by the embodiments of the present application, the first access point multi-link device or the second access point multi-link device sends the eighth information to the station multi-link device, so that the station multi-link device can learn (or explicitly learn) the context information transfer result in time, and the station multi-link device can clearly know which context information has been accepted by the second access point multi-link device and which context information has not been accepted by the second access point multi-link device, thereby effectively avoiding the problem in the continuity of data transmission between the station multi-link device and the second access point multi-link device caused by the station multi-link device mistakenly believing that some context information has been successfully accepted by the second access point multi-link device (it can also be understood that the problem in the continuity of data transmission between the station multi-link device and the second access point multi-link device caused by the mismatch between the context information at the station multi-link device and the context information at the second access point multi-link device can be effectively avoided).

[0308] It can be understood that in the existing roaming scheme, the first access point multi-link device automatically transfers the context information related to the station multi-link device to the second access point multi-link device after receiving the roaming request from the station multi-link device. The station multi-link device defaults that the context information transfer is successful, or the transferred context information is all accepted by the second access point multi-link device. That is to say, the station multi-link device can continue to perform data transmission with the second access point multi-link device based on the previous context information after completing the roaming. However, due to some reasons (such as the asymmetric capabilities of the first access point multi-link device and the second access point multi-link device), there may be a case that the second access point multi-link device does not accept the transferred context information. When this case occurs, the station multi-link device usually needs to re-negotiate the context information that is not accepted by the second access point multi-link device, and the station multi-link device does not know this situation and mistakenly believes that the context information transferred to the second access point multi-link device has been accepted by the second access point multi-link device, which may cause a problem in the continuity of data transmission between the station multi-link device and the second access point multi-link device. To solve this problem, in the scheme provided by the embodiments of the present application, the first access point multi-link device or the second access point multi-link device sends the eighth information to the station multi-link device, so that the station multi-link device can learn (or explicitly learn) the context information transfer result in time, and the station multi-link device can clearly know which context information has been accepted by the second access point multi-link device and which context information has not been accepted by the second access point multi-link device, thereby effectively avoiding the problem in the continuity of data transmission between the station multi-link device and the second access point multi-link device caused by the station multi-link device mistakenly believing that some context information has been successfully accepted by the second access point multi-link device (it can also be understood that the problem in the continuity of data transmission between the station multi-link device and the second access point multi-link device caused by the mismatch between the context information at the station multi-link device and the context information at the second access point multi-link device can be effectively avoided).

[0309] It can be understood that the communication schemes shown in FIG. 4, FIG. 6, FIG. 8, FIG. 10 and FIG. 11 can be implemented separately or in combination, and the specific implementation is not limited. For example, the communication scheme shown in FIG. 4 can be implemented in combination with the communication scheme shown in FIG. 6, or the communication scheme shown in FIG. 8 can be implemented in combination with the communication scheme shown in FIG. 10. For another example, the communication schemes shown in FIG. 4, FIG. 6, FIG. 8 and FIG. 10 can be implemented in combination with the communication scheme shown in FIG. 11. In one possible implementation, the communication scheme shown in FIG. 11 can be executed after all the steps of the communication schemes shown in FIG. 4, FIG. 6, FIG. 8 or FIG. 10, or can be executed after some steps of the communication schemes shown in FIG. 4, FIG. 6, FIG. 8 or FIG. 10. Similarly, some steps of the communication scheme shown in FIG. 4 can be implemented in combination with some steps of the communication scheme shown in FIG. 8, and the specific implementation is not limited.

[0310] It can be understood that, in order to implement the functions in the above embodiments, the station multi-link device, the first access point multi-link device and the second access point multi-link device include the corresponding hardware structures and / or software modules for performing the functions. Those skilled in the art can easily understand that the units and method steps of the examples described in combination with the embodiments disclosed in the present application can be implemented in the form of hardware or hardware and computer software. Whether a certain function is implemented in hardware or computer software driven hardware depends on the specific application scenario and design constraints of the technical solution.

[0311] FIG. 12 and FIG. 13 are structural schematic diagrams of possible communication apparatuses provided by the embodiments of the present application. The communication apparatuses can be used to implement the functions of the station multi-link device, the first access point multi-link device or the second access point multi-link device in the above method embodiments, and thus can also achieve the beneficial effects of the above method embodiments. In the embodiments of the present application, the communication apparatus can be the station multi-link device, the first access point multi-link device or the second access point multi-link device, and can also be a module (such as a chip) applied to the station multi-link device, the first access point multi-link device or the second access point multi-link device.

[0312] The communication apparatus 1200 shown in FIG. 12 includes a processing unit 1210 (or can be referred to as a processing module). Optionally, the communication apparatus 1200 shown in FIG. 12 can also include a transceiver unit 1220 (or can be referred to as a communication module or a transceiver module or a communication module, used for transmitting and receiving data). The communication apparatus 1200 can be used to implement the functions of the station multi-link device, the first access point multi-link device or the second access point multi-link device in the method embodiments shown in FIG. 4, FIG. 6, FIG. 7, FIG. 8, FIG. 10 and FIG. 11. For example, the transceiver unit 1220 can perform the receiving actions and the transmitting actions performed by the station multi-link device, the first access point multi-link device or the second access point multi-link device in the above method embodiments. The processing unit 1210 can perform the actions performed by the station multi-link device, the first access point multi-link device or the second access point multi-link device in the above method embodiments, except for the transmitting actions and the receiving actions.

[0313] When the communication apparatus 1200 is used to implement the functions of the first access point multi-link device in the method embodiment shown in FIG. 4: the processing unit 1210 is configured to determine that the station multi-link device roams from the first access point multi-link device to the second access point multi-link device. The processing unit 1210 is also configured to save the first context information of the station multi-link device within a first time length. The transceiver unit 1220 is configured to perform corresponding transceiving operations, such as can be used to receive data from the station multi-link device, or can be used to transmit information (such as first information) to the station multi-link device, etc.

[0314] When the communication apparatus 1200 is used to implement the functions of the first access point multi-link device in the method embodiment shown in FIG. 6: the transceiver unit 1220 is configured to transmit first information to the station multi-link device. The first information can be used to indicate that saving context information is supported, or the first information can be used to indicate that the second context information saved is supported. The second context information can include the first context information. The transceiver unit 1220 is configured to receive second information from the station multi-link device. The second information can be used to indicate that the context information of the station multi-link device is saved, or the second information can be used to indicate the identification of the first context information. The processing unit 1210 is configured to perform corresponding processing operations, such as can be used to generate the first information, etc.

[0315] When the communication device 1200 is used to implement the function of the site multi-link device in the method embodiment shown in FIG6 above: the transceiver unit 1220 is used to receive first information from the first access point multi-link device. The first information may be used to indicate support for saving context information, or the first information may be used to indicate support for saving second context information. The second context information may include the first context information. The first context information is the context information saved by the first access point multi-link device when the site multi-link device roams from the first access point multi-link device to the second access point multi-link device. The storage duration of the first context information is a first duration. The transceiver unit 1220 is also used to send second information to the first access point multi-link device. The second information may be used to indicate the saving of the site multi-link device's context information, or the second information may be used to indicate the identifier of the first context information. The processing unit 1210 is used to perform corresponding processing operations, such as generating the second information.

[0316] When the communication device 1200 is used to implement the function of the first access point multilink device in the method embodiment shown in FIG8 above: the processing unit 1210 is used to determine that the site multilink device roams from the first access point multilink device to the second access point multilink device. The processing unit 1210 is also used to save the configured link between the first access point multilink device and the site multilink device within a second time period. The transceiver unit 1220 is used to perform corresponding transceiver operations, such as receiving data from the site multilink device or sending information (such as first information) to the site multilink device.

[0317] When the communication device 1200 is used to implement the function of the first access point multi-link device in the method embodiment shown in FIG10: the transceiver unit 1220 is used to send fourth information to the site multi-link device. The fourth information can be used to indicate support for saving the configured link. The transceiver unit 1220 is also used to receive fifth information from the site multi-link device. The fifth information can be used to indicate saving the configured link between the first access point multi-link device and the site multi-link device. The processing unit 1210 is used to perform corresponding processing operations, such as generating the fourth information.

[0318] When the communication apparatus 1200 is configured to implement the functions of the station multi-link device in the method embodiments shown in FIG. 10: the transceiver unit 1220 is configured to receive fourth information from the first access point multi-link device. The fourth information can be used to indicate that saving the set link is supported. The transceiver unit 1220 is further configured to send fifth information to the first access point multi-link device. The fifth information can be used to indicate that the set link between the first access point multi-link device and the station multi-link device is saved. The saving duration of the set link is the second duration. The processing unit 1210 is configured to perform corresponding processing operations, such as generating the fifth information, etc.

[0319] When the communication apparatus 1200 is configured to implement the functions of the first access point multi-link device or the second access point multi-link device in the method embodiments shown in FIG. 11: the transceiver unit 1220 is configured to receive seventh information from the station multi-link device. The seventh information can be used to request roaming from the first access point multi-link device to the second access point multi-link device. The transceiver unit 1220 is further configured to send eighth information to the station multi-link device. The eighth information can be used to indicate the context information transfer result. The context information transfer result can include context information that has been accepted by the second access point multi-link device and / or context information that has not been accepted by the second access point multi-link device. The processing unit 1210 is configured to perform corresponding processing operations, such as generating the eighth information, etc.

[0320] When the communication apparatus 1200 is configured to implement the functions of the station multi-link device in the method embodiments shown in FIG. 11: the transceiver unit 1220 is configured to send seventh information to the first access point multi-link device or the second access point multi-link device. The seventh information can be used to request roaming from the first access point multi-link device to the second access point multi-link device. The transceiver unit 1220 is further configured to receive eighth information from the first access point multi-link device or the second access point multi-link device. The eighth information can be used to indicate the context information transfer result. The context information transfer result can include context information that has been accepted by the second access point multi-link device and / or context information that has not been accepted by the second access point multi-link device. The processing unit 1210 is configured to perform corresponding processing operations, such as generating the seventh information, etc.

[0321] Further details of the processing unit 1210 and the transceiver unit 1220 can be found in the above description of the method embodiments shown in FIG. 4, FIG. 6, FIG. 7, FIG. 8, FIG. 10 and FIG. 11, which will not be repeated here.

[0322] It should be understood that the transceiver unit 1220 in the embodiments of the present application can be implemented by a transceiver or a transceiver related circuit component, and the processing unit 1210 can be implemented by a processor or a processor related circuit component.

[0323] It should be noted that the division of the modules in the embodiments of the present application is illustrative, and is only a logical function division. Actual implementation can have another division manner. In addition, each functional unit in each embodiment of the present application can be integrated in one processing unit, or can be physically separated, or two or more units can be integrated in one unit. The integrated unit can be realized in the form of hardware or in the form of a software functional unit.

[0324] If the integrated unit is realized in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application essentially or the part that contributes to the prior art or the whole or part of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for causing a computer device (which can be a personal computer, a server, or the like) or a processor to perform all or part of the steps of the methods in the embodiments of the present application. The foregoing storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk, and various program codes that can be stored in the medium.

[0325] The communication apparatus 1300 shown in FIG. 13 includes a processor 1310. Optionally, the communication apparatus 1300 can further include at least one of a memory 1320, a transceiver 1330, and an antenna 1340.

[0326] The transceiver 1330 can be a transceiving unit, a transceiver, or a transceiving circuit, etc., used to implement a transceiving function. The transceiver 1330 can include a receiver and a transmitter. The receiver can be a receiver or a receiving circuit, etc., used to implement a receiving function; the transmitter can be a transmitter or a transmitting circuit, etc., used to implement a transmitting function.

[0327] The memory 1320 can store computer programs or software codes or instructions 1350, which can also be referred to as firmware. The processor 1310 can control the communication device 1300 by running the computer programs or software codes or instructions 1360 of the processor 1310, or by invoking the computer programs or software codes or instructions 1350 stored in the memory 1320, to implement the embodiments of the present application described above. The processor 1310 can be a central processing unit (CPU), and the memory 1320 can be a read-only memory (ROM) or a random access memory (RAM).

[0328] The processor 1310 and the transceiver 1330 described in the present application can be disposed on an integrated circuit (IC), an analog IC, a radio frequency integrated circuit (RFIC), a mixed-signal IC, an application specific integrated circuit (ASIC), a printed circuit board (PCB), or an electronic device.

[0329] The modules included in the communication device 1300 are only examples, and the present application does not limit the same.

[0330] When the communication device 1300 is used to implement the method embodiments described above, the processor 1310 can implement the functions of the processing unit 1210 described above, and the transceiver 1330 can implement the functions of the transceiving unit 1220 described above.

[0331] Based on the same idea, the embodiments of the present application also provide a possible communication system. The communication system can include a station multi-link device, a first access point multi-link device, and a second access point multi-link device. The station multi-link device can be used to implement the technical solutions related to the station multi-link device in the above embodiments, the first access point multi-link device can be used to implement the technical solutions related to the first access point multi-link device in the above embodiments, and the second access point multi-link device can be used to implement the technical solutions related to the second access point multi-link device in the above embodiments.

[0332] Based on the same idea, the embodiments of the present application further provide a computer program product, which comprises computer programs or instructions, and when the computer programs or instructions are run on a communication device (or a computer), the communication device (or the computer) is enabled to perform the method provided by the above embodiments.

[0333] Based on the same idea, the embodiments of the present application further provide a computer readable storage medium, which stores computer programs or instructions, and when the computer programs or instructions are executed by a communication device (or a computer), the communication device (or the computer) is enabled to perform the method provided by the above embodiments.

[0334] The storage medium can be any available medium that can be accessed by a computer. By way of example, and not limitation, such computer readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code means in the form of instructions or data structures and that can be accessed by a computer.

[0335] Based on the same idea, the embodiments of the present application further provide a chip, which can comprise a processor, and can further comprise a memory (or the chip is coupled with the memory), the processor executes program instructions in the memory, so as to enable the chip to perform the method provided by the above embodiments. The "coupling" means that two components are directly or indirectly combined with each other, such as the coupling can mean that the two components are electrically connected.

[0336] Based on the same idea, the embodiments of the present application further provide a chip system, which comprises a processor, and is used to support a computer device to realize the functions related to the communication device in the above embodiments. In a possible implementation, the chip system further comprises a memory, which is used to save necessary programs and data of the computer device. The chip system can be composed of a chip, or can contain the chip and other discrete devices.

[0337] It can be understood that the processor in the embodiments of the present application can be a central processing unit (CPU), and can also be other general-purpose processors, digital signal processors (DSP), application specific integrated circuits (ASIC), field programmable gate arrays (FPGA) or other programmable logic devices, transistor logic devices, hardware components or any combination thereof. The general-purpose processor can be a microprocessor or any conventional processor.

[0338] The method steps in the embodiments of the present application can be implemented in the form of hardware or by a processor executing software instructions. The software instructions can be composed of corresponding software modules, and the software modules can be stored in a random access memory, a flash memory, a read-only memory, a programmable read-only memory, an erasable programmable read-only memory, an electrically erasable programmable read-only memory, a register, a hard disk, a mobile hard disk, a compact disc read-only memory (CD-ROM) or any other form of storage medium well known in the art. An exemplary storage medium is coupled to the processor, so that the processor can read information from the storage medium and write information to the storage medium. Of course, the storage medium can also be an integral part of the processor. The processor and the storage medium can be located in an ASIC. In addition, the ASIC can be located in a communication device. Of course, the processor and the storage medium can also exist as discrete components in the communication device.

[0339] In the above embodiments, all or part of the embodiments can be implemented by software, hardware, firmware or any combination thereof. When implemented by software, all or part of the embodiments can be implemented in the form of a computer program product. The computer program product includes one or more computer programs or instructions. The computer program refers to a set of instructions for instructing an electronic computer or other devices with message processing capability to perform each step. The computer program is usually written in a certain programming language and runs on a certain target architecture. When the computer program or instructions are loaded and executed on the computer, all or part of the processes or functions described in the embodiments of the present application are performed. The computer can be a general-purpose computer, a special-purpose computer, a computer network or other programmable devices. The computer program or instructions can be stored in a computer readable storage medium or transferred from one computer readable storage medium to another computer readable storage medium, for example, the computer program or instructions can be transferred from one website, computer, server or data center to another website, computer, server or data center through wired or wireless mode. The computer readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server, data center and the like integrated with one or more available media. The available medium can be a magnetic medium, such as a floppy disk, a hard disk, a magnetic tape; or an optical medium, such as a digital video disc; or a semiconductor medium, such as a solid state disk. The computer readable storage medium can be a volatile or non-volatile storage medium, or can include both volatile and non-volatile storage media.

[0340] In various embodiments of the present application, the terms and / or descriptions of different embodiments are consistent and can be referred to each other if there is no special description and logical conflict. The technical features in different embodiments can be combined to form new embodiments according to their inherent logical relationship.

[0341] In the present application, "at least one" means one or more, and "multiple" means two or more. "And / or" describes the association relationship between the associated objects, which means that there can be three kinds of relationships, for example, A and / or B, which can represent the following three cases: A exists alone, A and B exist together, and B exists alone, where A and B can be singular or plural. In the literal description of the present application, the character " / ", generally represents that the front and rear associated objects have an "or" relationship; in the formula of the present application, the character " / ", represents that the front and rear associated objects have a "division" relationship.

[0342] It can be understood that various digital numbers involved in the embodiments of the present application are only distinguished for the convenience of description, and are not used to limit the scope of the embodiments of the present application. The size of the serial number of the above processes does not mean the order of execution, and the execution order of the processes should be determined according to its function and inherent logic.

Claims

1. A communication method characterized by comprising: The method applied to a first access point multi-link device comprises: determining that a station multi-link device roams from the first access point multi-link device to a second access point multi-link device; saving first context information of the station multi-link device within a first time length.

2. The method of claim 1, wherein, The method further comprises: sending first information to the station multi-link device, the first information being used to indicate support for saving context information, or the first information being used to indicate support for saving second context information, the second context information comprising the first context information; receiving second information from the station multi-link device, the second information being used to indicate saving context information of the station multi-link device, or the second information being used to indicate an identifier of the first context information.

3. The method of claim 1 or 2, wherein, The method further comprises: sending third information to the station multi-link device, the third information being used to indicate the first time length.

4. The method according to any one of claims 1 to 3, characterized in that, The method further comprises: starting a timer when receiving a first roaming request from the station multi-link device or sending a first roaming response to the station multi-link device, the timer counting for the first time length, the first roaming request corresponding to the first roaming response, the first roaming request being used to request roaming from the first access point multi-link device to the second access point multi-link device; saving the first context information when the timer counting does not time out; or deleting the first context information when the timer counting times out.

5. A communication method characterized by comprising: The method applied to a station multi-link device comprises: receiving first information from a first access point multi-link device, the first information being used to indicate support for saving context information, or the first information being used to indicate support for saving second context information, the second context information comprising first context information, the first context information being context information saved by the first access point multi-link device when the station multi-link device roams from the first access point multi-link device to a second access point multi-link device, a saving time length of the first context information being a first time length; sending second information to the first access point multi-link device, the second information being used to indicate saving context information of the station multi-link device, or the second information being used to indicate an identifier of the first context information.

6. The method of claim 5, wherein, The method further comprises: receiving third information from the first access point multi-link device, the third information being used to indicate the first time length.

7. The method of claim 3 or 6, wherein, The third information carries a timeout interval element, the timeout interval element comprising the first time length.

8. The method of claim 3, 6 or 7, wherein, The third information is one of the following: a beacon frame, a probe response frame, an association response frame, and a re-association response frame.

9. The method according to any one of claims 1 to 8, wherein, The context information comprises at least one of the following: a pairwise transient key, a block acknowledgement, a flow classification service, a mirror flow classification service, a target wake-up time, a traffic identifier and a link-to-link mapping, and an emergency preparedness communication service.

10. The method of any one of claims 1-9, wherein, The first time length is a preset context information saving time length; or The first time length is a roaming cutoff time length.

11. A communication method, comprising: The method applied to a first access point multi-link device comprises: determining that a station multi-link device roams from the first access point multi-link device to a second access point multi-link device; maintaining a setup link between the first access point multi-link device and the station multi-link device for a second time duration.

12. The method of claim 11, wherein, The method further includes: sending fourth information to the station multi-link device, the fourth information being used to indicate that maintaining a setup link is supported; receiving fifth information from the station multi-link device, the fifth information being used to indicate that the setup link between the first access point multi-link device and the station multi-link device is maintained.

13. The method of claim 11 or 12, wherein, The method further includes: sending sixth information to the station multi-link device, the sixth information being used to indicate the second time duration.

14. The method according to any one of claims 11 to 13, wherein, The method further includes: starting a timer when receiving a first roaming request from the station multi-link device or sending a first roaming response to the station multi-link device, the timer counting for the second time duration, the first roaming request corresponding to the first roaming response, the first roaming request being used to request roaming from the first access point multi-link device to the second access point multi-link device; maintaining the setup link when the timer does not time out; or deleting the setup link when the timer times out.

15. A method of communication, comprising: The method applied to a station multi-link device includes: receiving fourth information from a first access point multi-link device, the fourth information being used to indicate that maintaining a setup link is supported; sending fifth information to the first access point multi-link device, the fifth information being used to indicate that the setup link between the first access point multi-link device and the station multi-link device is maintained, a time duration for maintaining the setup link being a second time duration.

16. The method of claim 15, wherein, The method further includes: receiving sixth information from the first access point multi-link device, the sixth information being used to indicate the second time duration.

17. The method of claim 13 or 16, wherein, The sixth information carries a timeout interval element, and the timeout interval element includes the second time duration.

18. The method of claim 13, 16 or 17, wherein, The sixth information is one of the following: a beacon frame, a probe response frame, an association response frame, and a re-association response frame.

19. The method of any one of claims 11-18, wherein, The second time duration is a preset setup link maintaining duration; or The second time duration is a roaming cutoff duration.

20. A method of communication, comprising: The method applied to a first access point multi-link device or a second access point multi-link device includes: receiving seventh information from a station multi-link device, the seventh information being used to request roaming from the first access point multi-link device to the second access point multi-link device; sending eighth information to the station multi-link device, the eighth information being used to indicate a context information transfer result, the context information transfer result including context information that has been accepted by the second access point multi-link device and / or context information that has not been accepted by the second access point multi-link device.

21. The method of claim 20, wherein, If the context information transfer result includes context information that has not been accepted by the second access point multi-link device, the eighth information further includes third context information recommended by the second access point multi-link device, the third context information corresponding to the context information that has not been accepted by the second access point multi-link device.

22. The method of claim 20 or 21, wherein, The method further includes: receiving ninth information from the station multi-link device, the ninth information being used for indicating whether context information transfer is needed or the ninth information being used for indicating an identity of context information that needs to be transferred.

23. A method of communication, comprising: The method is applied to a station multi-link device, and the method comprises: sending seventh information to a first access point multi-link device or a second access point multi-link device, the seventh information being used for requesting roaming from the first access point multi-link device to the second access point multi-link device; receiving eighth information from the first access point multi-link device or the second access point multi-link device, the eighth information being used for indicating a context information transfer result, the context information transfer result comprising context information that has been accepted by the second access point multi-link device and / or context information that has not been accepted by the second access point multi-link device.

24. The method of claim 23, wherein, If the context information transfer result comprises context information that has not been accepted by the second access point multi-link device, the eighth information further comprises third context information recommended by the second access point multi-link device, the third context information corresponding to the context information that has not been accepted by the second access point multi-link device.

25. The method of claim 23 or 24, wherein, The method further comprises: sending ninth information to the first access point multi-link device or the second access point multi-link device, the ninth information being used for indicating whether context information transfer is needed or the ninth information being used for indicating an identity of context information that needs to be transferred.

26. The method of any one of claims 20-25, wherein, The context information comprises at least one of the following: a pair-wise temporary key, a block acknowledgement, a flow classification service, a mirror flow classification service, a target wake-up time, a traffic identifier and a link-to-link mapping, and an emergency preparedness communication service.

27. A communications device, characterized by The apparatus comprises a module or unit for performing the method according to any one of claims 1-4, or a module or unit for performing the method according to any one of claims 5-10, or a module or unit for performing the method according to any one of claims 11-14, or a module or unit for performing the method according to any one of claims 15-19, or a module or unit for performing the method according to any one of claims 20-22, or a module or unit for performing the method according to any one of claims 23-26.

28. A communications device, characterized by The apparatus comprises a processor and a memory; The memory is configured to store a computer program; The processor is configured to execute the computer program in the memory, so that the method according to any one of claims 1-4 or the method according to any one of claims 5-10 or the method according to any one of claims 11-14 or the method according to any one of claims 15-19 or the method according to any one of claims 20-22 or the method according to any one of claims 23-26 is implemented.

29. A computer-readable storage medium, characterized in that, The computer readable storage medium stores computer programs or instructions which, when executed by the communication device, cause the method of any one of claims 1-4 or the method of any one of claims 5-10 or the method of any one of claims 11-14 or the method of any one of claims 15-19 or the method of any one of claims 20-22 or the method of any one of claims 23-26 to be implemented.

30. A computer program product, characterised in that, The computer program product comprises computer programs or instructions which, when run on the communication device, cause the method of any one of claims 1-4 or the method of any one of claims 5-10 or the method of any one of claims 11-14 or the method of any one of claims 15-19 or the method of any one of claims 20-22 or the method of any one of claims 23-26 to be implemented.

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