Communication method and apparatus

Abstract

The present application belongs to the technical field of communications. Provided are a communication method and apparatus, so as to improve the communication performance of stations (STAs). The method comprises: defining a first moment at which a first communication apparatus starts switching from a second channel to a first channel, such that the first moment is at or before an end moment of a busy period of the first channel, and thus the first communication apparatus can switch back to the first channel before the duration of losing medium synchronization of the first channel reaches a medium synchronization threshold, so as to avoid the loss of medium synchronization (blind state) of the first communication apparatus and further avoid triggering a medium synchronization recovery procedure; moreover, the impact on the communication performance of a legacy STA remaining on a primary channel or a non-AP STA supporting only a legacy protocol may be avoided. Therefore, the communication performance of the STAs can be improved in this embodiment.

Description

Communication methods and devices

[0001] This application claims priority to Chinese Patent Application No. 202411603673.6, filed with the State Intellectual Property Office of China on November 11, 2024, entitled "Communication Method and Apparatus", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of communication technology, and in particular to communication methods and apparatus. Background Technology

[0003] Currently, devices using the IEEE 802.11 protocol for wireless communication logically divide their high-bandwidth channels into sub-channels in 20MHz units. For example, an 80MHz channel might have four 20MHz sub-channels, and a 160MHz channel might have eight 20MHz sub-channels. Within these sub-channels, the device knows which sub-channel is the primary channel and the rest are non-primary channels based on the configuration information of the basic service set (BSS). While the primary channel access mechanism is logically clean and simple to operate, as device deployments become denser and bandwidths increase, the frequency of spectrum usage resulting from primary channel access decreases. For example, if a 160MHz site detects only the primary 20MHz channel as busy, while all other sub-channels are detected as idle, then according to the primary channel access mechanism, this device cannot use any channel and must back off. However, in reality, the other sub-channels are idle and theoretically could be used. Therefore, a method was proposed that when the primary channel is busy, transmission can be performed through an idle non-primary channel (anchor channel) without backoff. In this case, the device switches to the anchor channel and performs preamble detection (PD) on the anchor channel. This operation is called non-primary channel access (NPCA). The idle non-primary channel can also be called the NPCA primary channel.

[0004] Switching between the main channel and the NPCA main channel requires a switching delay. How to ensure communication performance while taking the switching delay into account is a current research problem. Summary of the Invention

[0005] This application provides a communication method and apparatus to ensure improved communication performance of stations in a system even with switching delays.

[0006] To achieve the above objectives, this application adopts the following technical solution:

[0007] In a first aspect, a communication method is provided. This method can be executed by a first communication device, or by a component of the first communication device, such as a processor, chip, or chip system of the first communication device, or by a logic module or software capable of implementing all or part of the first communication device. The method includes: acquiring a first moment; the first moment being the end of a busy period for a first channel, or the first moment being before the end of the busy period; the first communication device communicating on a second channel before the first moment; and initiating a switch from the second channel to the first channel at the first moment; wherein the first communication device switches back to the first channel before the duration of loss of medium synchronization on the first channel reaches a medium synchronization threshold (e.g., aMediumSyncThershold).

[0008] Therefore, by limiting the first moment when the first communication device switches from the second channel to the first channel, ensuring that the first moment is at or before the end of the busy time of the first channel, the first communication device can switch back to the first channel before the duration of the loss of media synchronization on the first channel reaches the media synchronization threshold. This avoids the problem of the first communication device losing media synchronization (blind state) and further triggering the media synchronization recovery process. Moreover, it avoids affecting the communication performance of traditional STA sites that remain on the main channel or non-AP STA sites that only support older versions of protocols, thereby improving the communication performance of the sites.

[0009] In one possible design, the first time is determined based on the target time; the target time is determined based on at least one of the following: the busy time of the first channel, the switchback delay of the first communication device, the switchback delay of the second communication device, and the media synchronization threshold; the first communication device and the second communication device communicate with each other through the first channel and / or the second channel.

[0010] Optionally, the first moment is the target moment; or the first moment is before the target moment, and the duration between the first moment and the target moment is less than the duration required to complete one frame interaction on the second channel.

[0011] Optionally, the target time is the time corresponding to the target duration that is earlier than the end time of the busy time of the first channel; wherein, the target duration is the switchback delay of the first communication device, or the difference between the switchback delay of the second communication device and the media synchronization threshold.

[0012] Optionally, if the switchback delay of the first communication device is greater than or equal to the difference between the switchback delay of the second communication device and the media synchronization threshold, then the target duration is the switchback delay of the first communication device; if the switchback delay of the first communication device is less than the difference between the switchback delay of the second communication device and the media synchronization threshold, then the target duration is the difference between the switchback delay of the second communication device and the media synchronization threshold; if the first communication device is an AP, and the second communication device is some or all of the STAs associated with the AP, then the switchback delay of the second communication device is the maximum, minimum, or average value of the switchback delays of all or some of the devices in the second communication device.

[0013] Therefore, the AP can switch back to the second channel before the first channel's busy period ends, avoiding media synchronization loss and ensuring the communication performance of stations remaining on the first channel is not affected. Some or all of the aforementioned STAs can also switch back to the second channel before the first channel's busy period ends, avoiding media synchronization loss.

[0014] In one possible design, the first moment is the moment when the duration of the first communication device ceasing frame interaction in the second channel reaches the duration threshold.

[0015] In one possible design, a handover instruction information is sent to at least one device in the second communication device. The handover instruction information is used to instruct the second communication device to initiate a handover from the second channel to the first channel at a second time. The handover instruction information is carried in a downlink frame sent during the capability negotiation phase or update phase of the target mode. The target mode is any one of the following: NPCA mode, DPS mode, DSO mode, IDC or DUI or DUO mode.

[0016] Optionally, the second time is the first time; or, the second time is the first time delayed by a preset duration; or, the second time is the time corresponding to the switchback delay of the second communication device, which is earlier than the end time of the busy time of the first channel.

[0017] Therefore, by switching the AP back to the first channel in advance and stabilizing on the first channel in advance, the STA can quickly stabilize after switching back, thus improving the communication performance of the system's resite stations.

[0018] Secondly, a communication method is provided. This method can be executed by a first communication device, or by a component of the first communication device, such as a processor, chip, or chip system of the first communication device, or by a logic module or software capable of implementing all or part of the first communication device. The method includes: switching from a first channel to a second channel when channel switching conditions are met; wherein the channel switching conditions include: the dwell time of the first communication device on the second channel is greater than or equal to the time required for the first communication device to access the second channel and perform frame interaction on the second channel; or, the busy duration of the first channel is greater than or equal to a duration threshold, wherein within the busy duration of the first channel, the first communication device can complete the switch from the first channel to the second channel, and access the second channel and perform frame interaction on the second channel.

[0019] Therefore, switching from the first channel to the second channel is only performed when the dwell time of the first communication device in the second channel is greater than or equal to the time required for the first communication device to access the second channel and perform frame interaction in the second channel, or when the first communication device can complete the switch from the first channel to the second channel and access the second channel and perform frame interaction within the busy duration of the first channel. This ensures that the first communication device can perform beneficial communication in the second channel and improves communication performance.

[0020] In one possible design, the communication duration is the difference between the busy duration of the first channel and the handover delay of the first communication device; or, the dwell time is the difference between the busy duration and the sum of the handover delay and the switchback delay of the first communication device; or, the dwell time is the difference between the busy duration and the sum of the handover delay of the first communication device and the switchback delay of the second communication device; or, the dwell time is the difference between the sum of the busy duration and the media synchronization threshold and the handover delay of the first communication device; or, the dwell time is the difference between the sum of the busy duration and the media synchronization threshold and the sum of the handover delay of the first communication device and the switchback delay of the second communication device.

[0021] In one possible design, the first communication device is an AP, and the second communication device is some or all of the STAs associated with the AP; the handover delay of the second communication device is the maximum, minimum, or average of the handover delays of all or some of the STAs in the second communication device.

[0022] In one possible design, the first communication device is an AP, and the second communication device is some or all of the STAs associated with the AP; the duration threshold is greater than or equal to the sum of the maximum delay and the duration required to access the second channel and perform frame interaction on the second channel; the maximum delay is the maximum value of the sum of the handover delay and the switchback delay in the first and second communication devices, or the maximum value of the handover delay in the first and second communication devices, or the maximum value of the switchback delay in the first and second communication devices.

[0023] In one possible design, the conditions for not satisfying channel handover include at least one of the following: the sum of the handover delay and the switchback delay in the second communication device is greater than or equal to the difference between a duration threshold and the time required to access the second channel and perform frame interaction on the second channel; or the handover delay or switchback delay in the second communication device is greater than or equal to the difference between a duration threshold and the time required to access the second channel and perform frame interaction on the second channel. That is, STAs with larger handover delays do not perform channel handover, which ensures that STAs with smaller handover delays can perform beneficial communication on the second channel and reduces unnecessary overhead for STAs with larger handover delays.

[0024] In one possible design, the conditions for channel switching also include: at least one second communication device having a dwell time on the second channel greater than or equal to the time required for the second communication device to access the second channel and perform frame exchange on the second channel; or at least one second communication device having a busy duration on the first channel greater than or equal to a duration threshold, wherein, within the busy duration of the first channel, the second communication device can complete the switch from the first channel to the second channel, and access the second channel and perform frame exchange on the second channel. Channel switching is only meaningful and allows for beneficial communication when the AP and at least one STA switch to the second channel together.

[0025] In one possible design, the busy duration of the first channel is from the moment when the first communication device decides to start switching from the first channel to the second channel to the end of the busy time of the first channel.

[0026] In one possible design, the first communication device is an AP, and the second communication device is some or all of the STAs associated with the AP. The time required to complete access to the second channel and perform frame interaction on the second channel is determined by at least one of the types of uplink communication, downlink communication, and channel access. The type of channel access may include any of the following: contention, scheduling, scheduling by the AP only in the first TXOP, downlink transmission by the AP or sending downlink frames by the AP, contention by the AP only in the first TXOP, sending the first frame by the AP, and a mixture of contention and scheduling.

[0027] In one possible design, information indicating the time required to complete access to the second channel and perform frame interaction on the second channel is carried in the uplink or downlink frames negotiated and sent during the capability negotiation phase or update phase of the target mode; wherein the target mode is any one of the following: NPCA mode, DPS mode, DSO mode, IDC or DUI or DUO mode.

[0028] In one possible design, the uplink frame is at least one of the following: association request frame, or reassociation request frame, target mode enable frame, target mode notification frame, or target mode dedicated management frame; the downlink frame is at least one of the following: beacon frame, data pending transmission indication information, beacon frame or transmission indication mapping frame, or target mode dedicated management frame.

[0029] Thirdly, a communication method is provided. This method can be executed by a second communication device, or by a component of the second communication device, such as a processor, chip, or chip system of the second communication device, or by a logic module or software capable of implementing all or part of the second communication device. The method includes: acquiring channel access indication information; if the channel access indication information indicates that the channel access type of the second communication device is a mix of scheduling and contention, then, based on the busy time of the first channel and the channel access indication information, synchronizing the current access type of the second channel with the first communication device, the current access type including waiting for scheduling by the first communication device or participating in contention for the second channel; the first channel being a channel through which the first and second communication devices communicate outside of busy times; and accessing the second channel using the current access type.

[0030] Therefore, the first communication device can instruct the second communication device to use a hybrid scheduling and contention approach for channel access. Based on the busy time of the first channel and channel access indication information, it determines whether the current access method is to compete for the second channel or wait for scheduling by the first communication device. This allows for waiting for scheduling when there are many STAs, reducing the probability of collisions among multiple STAs and enabling efficient access for multiple STAs. When there are fewer STAs, the collision probability is low, and contention-based access is more efficient, avoiding the overhead of scheduling. In short, it achieves efficient channel access within a limited time.

[0031] In one possible design scheme, if the current access type is waiting for scheduling by the first communication device, accessing the second channel using the current access type includes: receiving scheduling information sent by the first communication device.

[0032] In one possible design, the channel access indication information also includes a busy duration threshold; when the busy time of the first channel is greater than or equal to the busy duration threshold, and / or the number of second communication devices switching to the second channel exceeds the quantity threshold, the current access type is waiting for the first communication device to schedule; the number of second communication devices switching to the second channel is determined based on the busy time of the first channel, the busy duration threshold, or the switching delay and handover delay of the second communication device; when the busy time of the first channel is less than the busy duration threshold, and / or the number of second communication devices switching to the second channel does not exceed the quantity threshold, the current access type is participating in the contention for the second channel.

[0033] In one possible design, the first communication device is an access point (AP), and the second communication device is a STA associated with the AP. The acquisition of channel access indication information includes: receiving channel access indication information sent by the first communication device; the channel access indication information can indicate that the channel access type of the second communication device is any of the following: waiting for scheduling, only scheduled by the AP in the first TXOP, AP downlink transmission or AP sending downlink frames, only the first TXOP is limited to AP contention, AP sends the first frame, participating in contention and the type of contention, mixed scheduling and contention, and scheduling priority.

[0034] In one possible design, the first communication device is an access point (AP), and the second communication device is all or some of the STAs associated with the AP. The method further includes: sending channel access suggestion information to the first communication device, wherein the channel access suggestion information can suggest that the channel access type of the second communication device is any one of the following: scheduling, scheduling by the AP only in the first TXOP, AP downlink transmission or AP sending downlink frames, limiting only AP contention in the first TXOP, AP sending the first frame, participation in contention and the type of contention, mixed scheduling and contention, and scheduling priority; and obtaining channel access indication information, including: receiving channel access indication information returned by the first communication device based on the access indication suggestion information.

[0035] In one possible design, the channel access indication information is carried in the downlink frame during the capability negotiation or update phase of the target mode, and the channel access indication suggestion information is carried in the uplink frame during the capability negotiation or update phase of the target mode; the target mode is any one of the following: NPCA mode, DPS mode, DSO mode, IDC or DUI or DUO mode.

[0036] In one possible design, the uplink frame is at least one of the following: association request frame, or reassociation request frame, target mode enable frame, target mode notification frame, or target mode dedicated management frame; the downlink frame is at least one of the following: beacon frame, data pending transmission indication information, beacon frame or transmission indication mapping frame, or target mode dedicated management frame.

[0037] In one possible design, after obtaining channel access indication information, the process further includes: if the channel access indication information indicates that the second communication device's channel access type is scheduling priority, waiting for scheduling information sent by the first communication device; if the waiting time exceeds a waiting threshold, then participating in the contention for the second channel. This avoids the second communication device continuously waiting for scheduling from the first communication device, thus improving communication performance.

[0038] Fourthly, a communication method is provided. This method can be executed by a first communication device, or by a component of the first communication device, such as a processor, chip, or chip system of the first communication device, or by a logic module or software capable of implementing all or part of the first communication device. The method includes: sending channel access indication information to a second communication device; if the channel access indication information indicates that the channel access type of the second communication device is a mix of scheduling and contention, then synchronizing the current access type of the second channel with the second communication device according to the busy time of the first channel and the channel access indication information, wherein the current access type includes waiting for scheduling by the first communication device or participating in contention for the second channel; the first channel is a channel through which the first and second communication devices communicate outside of busy times; if the current access type is waiting for scheduling by the first communication device, then sending scheduling information to the second communication device.

[0039] In one possible design, the channel access indication information also includes a busy duration threshold; when the busy time of the first channel is greater than or equal to the busy duration threshold, and / or the number of second communication devices switching to the second channel exceeds the quantity threshold, the current access type is waiting for the first communication device to schedule; the number of second communication devices switching to the second channel is determined based on the busy time of the first channel, the busy duration threshold, or the switching delay and handover delay of the second communication device; when the busy time of the first channel is less than the busy duration threshold, and / or the number of second communication devices switching to the second channel does not exceed the quantity threshold, the current access type is participating in the contention for the second channel.

[0040] In one possible design, the first communication device is an access point (AP), and the second communication device is all or some of the STAs associated with the AP. The channel access indication information can indicate the channel access type of the second communication device as any of the following: waiting for scheduling, only scheduled by the AP in the first TXOP, AP downlink transmission or AP sending downlink frames, only the first TXOP is limited to AP contention, AP sends the first frame, participating in contention and the type of contention, and a mixture of scheduling and contention.

[0041] In one possible design, the first communication device is an access point (AP), and the second communication device is all or some of the STAs associated with the AP. The method further includes: receiving channel access suggestion information sent by the second communication device, wherein the channel access suggestion information can suggest that the channel access type of the second communication device is any one of the following: scheduling, scheduling by the AP only in the first TXOP, AP downlink transmission or AP sending downlink frames, limiting only AP contention in the first TXOP, AP sending the first frame, participating in contention and the type of contention, and a mixture of scheduling and contention; and sending channel access indication information to the second communication device, including: sending channel access indication information returned according to the access indication suggestion information to the second communication device.

[0042] In one possible design, the channel access indication information is carried in the downlink frame during the capability negotiation or update phase corresponding to the target mode of the second channel, and the channel access indication suggestion information is carried in the uplink frame during the capability negotiation or update phase corresponding to the target mode of the second channel; the target mode is any one of the following: NPCA mode, DPS mode, DSO mode, IDC or DUI or DUO mode.

[0043] In one possible design, the uplink frame is at least one of the following: association request frame, or reassociation request frame, target mode enable frame, target mode notification frame, or target mode dedicated management frame; the downlink frame is at least one of the following: beacon frame, data pending transmission indication information, beacon frame or transmission indication mapping frame, or target mode dedicated management frame.

[0044] In one possible design, the first communication device is an access point (AP), and the third communication device is a STA associated with the AP other than the second communication device. The method further includes sending target channel access indication information to the third communication device, wherein the channel access type indicated by the target channel access indication information of the third communication device is the same as or different from the channel access type of the second communication device.

[0045] Furthermore, other technical effects of the communication method described in the fourth aspect can be referred to the technical effects of the communication method described in the third aspect, and will not be repeated here.

[0046] Fifthly, a communication device is provided. This communication device is used to perform the communication method described in any one of the first, second, third, or fourth aspects.

[0047] In this application, the communication device described in the fifth aspect can be a terminal device or a network device, or a chip (system) or other component or assembly, or a device containing the terminal device or network device. The aforementioned chip (system) or other component or assembly can all be disposed within the terminal device or network device.

[0048] It should be understood that the communication apparatus described in the fifth aspect includes modules, units, or means that implement the communication method described in any of the first, second, third, or fourth aspects above. These modules, units, or means can be implemented in hardware, software, or by hardware executing corresponding software. The hardware or software includes one or more modules or units for performing the functions involved in the aforementioned communication method.

[0049] Sixthly, a communication device is provided. The communication device includes a processor configured to execute the communication method described in any one of the possible implementations of the first, second, third, or fourth aspects.

[0050] In one possible design, the communication device described in the sixth aspect may further include a transceiver. This transceiver may be a transceiver circuit or an interface circuit. The transceiver can be used for communication between the communication device described in the sixth aspect and other communication devices.

[0051] In one possible design, the communication device described in the sixth aspect may further include a memory. This memory may be integrated with the processor or disposed separately. The memory may be used to store computer programs and / or data relating to the communication method described in any of the first, second, third, or fourth aspects.

[0052] In this application, the communication device described in the sixth aspect can be a terminal device or a network device, or a chip (system) or other component or assembly, or a device containing the terminal device or network device. The aforementioned chip (system) or other component or assembly can all be disposed within the terminal device or network device.

[0053] A seventh aspect provides a communication device. The communication device includes a processor coupled to a memory, the processor being configured to execute a computer program stored in the memory, such that the communication device performs the communication method described in any one of the first, second, third, or fourth aspects.

[0054] In one possible design, the communication device described in the seventh aspect may further include a transceiver. This transceiver may be a transceiver circuit or an interface circuit. The transceiver can be used for communication between the communication device described in the seventh aspect and other communication devices.

[0055] In this application, the communication device described in the seventh aspect can be a terminal device or a network device, or a chip (system) or other component or assembly, or a device containing the terminal device or network device. The aforementioned chip (system) or other component or assembly can all be disposed within the terminal device or network device.

[0056] Eighthly, a communication device is provided, comprising: a processor and a memory; the memory is used to store a computer program, which, when executed by the processor, causes the communication device to perform the communication method described in any one of the first, second, third, or fourth aspects.

[0057] In one possible design, the communication device described in the eighth aspect may further include a transceiver. This transceiver may be a transceiver circuit or an interface circuit. The transceiver can be used for communication between the communication device described in the eighth aspect and other communication devices.

[0058] In this application, the communication device described in the eighth aspect can be a terminal device or a network device, or a chip (system) or other component or assembly, or a device containing the terminal device or network device. The aforementioned chip (system) or other component or assembly can all be disposed within the terminal device or network device.

[0059] A ninth aspect provides a communication device comprising: a processor; the processor being configured to be coupled to a memory and, after reading a computer program from the memory, to execute a communication method according to the computer program as described in any one of the first, second, third, or fourth aspects.

[0060] In one possible design, the communication device described in the ninth aspect may further include a transceiver. This transceiver may be a transceiver circuit or an interface circuit. The transceiver can be used for communication between the communication device described in the ninth aspect and other communication devices.

[0061] In this application, the communication device described in the ninth aspect can be a terminal device or a network device, or a chip (system) or other component or assembly, or a device containing the terminal device or network device. The aforementioned chip (system) or other component or assembly can all be disposed within the terminal device or network device.

[0062] In a tenth aspect, a processor is provided. The processor is configured to execute the communication method described in any one of the possible implementations of the first, second, third, or fourth aspects.

[0063] Eleventhly, a communication system is provided. The communication system includes one or more terminal devices and one or more network devices.

[0064] In a twelfth aspect, a computer-readable storage medium is provided, comprising: a computer program or instructions; when the computer program or instructions are executed on a computer, causing the computer to perform the communication method described in any one of the possible implementations of the first, second, third, or fourth aspects.

[0065] In a thirteenth aspect, a computer program product is provided, comprising a computer program or instructions that, when executed on a computer, cause the computer to perform the communication method described in any one of the possible implementations of the first, second, third, or fourth aspects.

[0066] Furthermore, the technical effects of the communication devices described in the fifth to thirteenth aspects above can be referred to the technical effects of the communication methods described in the first, second, third, or fourth aspects above, and will not be repeated here. Attached Figure Description

[0067] Figure 1 is a schematic diagram of a basic service set structure and working principle provided in this application;

[0068] Figure 2 is a schematic diagram illustrating the principle of sub-channel partitioning and occupancy provided in this application;

[0069] Figure 3 is a schematic diagram of an initial control frame application method provided in this application;

[0070] Figure 4 is a schematic diagram of another initial control frame application method provided in this application;

[0071] Figure 5 is a schematic diagram illustrating the principle of sub-channel switching and contention provided in this application;

[0072] Figure 6 is a schematic diagram illustrating the principle of another sub-channel division and occupancy provided in this application;

[0073] Figure 7 is a schematic diagram illustrating the principle of applying the DPS mode provided in this application;

[0074] Figure 8 is a schematic diagram of the structure of a communication system provided in this application;

[0075] Figure 9 is a flowchart illustrating a communication method provided in this application;

[0076] Figure 10 is a schematic diagram of the timing of channel switching between AP and STAs provided in this application;

[0077] Figure 11 is a schematic diagram of the timing of STA channel switching provided in this application;

[0078] Figure 12 is a flowchart illustrating another communication method provided in this application;

[0079] Figure 13 is a flowchart illustrating another communication method provided in this application;

[0080] Figure 14 is a schematic diagram of an NPA element provided in this application;

[0081] Figure 15 is a schematic diagram of a DPS element provided in this application;

[0082] Figure 16 is a schematic diagram of a DSO element provided in this application;

[0083] Figure 17 is a schematic diagram of an IDC, DUI, or DUO element provided in this application;

[0084] Figure 18 is a schematic diagram of the communication device provided in this application.

[0085] Figure 19 is a schematic diagram of the structure of the communication device provided in this application. Detailed Implementation

[0086] In the description of this application, unless otherwise stated, " / " indicates that the objects before and after are in an "or" relationship. For example, A / B can mean A or B. "And / or" in this application is merely a description of the relationship between the related objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, and B exists alone. A and B can be singular or plural.

[0087] In the description of this application, unless otherwise stated, "multiple" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of a single item or a plurality of items. For example, at least one of a, b, or c can mean: a, b, c, ab, ac, bc, or abc, where a, b, and c can be single or multiple.

[0088] Furthermore, to facilitate a clear description of the technical solutions in the embodiments of this application, the terms "first" and "second" are used in the embodiments of this application to distinguish identical or similar items with substantially the same function and effect. Those skilled in the art will understand that the terms "first" and "second" do not limit the quantity or execution order, and the terms "first" and "second" are not necessarily different.

[0089] In the embodiments of this application, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design that is described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design. Specifically, the use of terms such as "exemplary" or "for example" is intended to present the relevant concepts in a specific manner to facilitate understanding.

[0090] It is understood that the term "embodiment" used throughout the specification means that a specific feature, structure, or characteristic related to an embodiment is included in at least one embodiment of this application. Therefore, various embodiments throughout the specification do not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. It is understood that in the various embodiments of this application, the sequence number of each process does not imply the order of execution; the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0091] It is understood that in this application, "...when" and "if" both refer to the corresponding processing that will be carried out under certain objective circumstances, and are not limited to a specific time, nor do they require a judgment action to be performed during implementation, nor do they imply any other limitations.

[0092] It is understood that some optional features in the embodiments of this application can be implemented independently in certain scenarios without relying on other features, such as the current solution on which they are based, to solve the corresponding technical problems and achieve the corresponding effects. Alternatively, they can be combined with other features as needed in certain scenarios. Correspondingly, the apparatus given in the embodiments of this application can also implement these features or functions, which will not be elaborated here.

[0093] In this application, unless otherwise specified, the same or similar parts between the various embodiments can be referred to each other. In the various embodiments of this application, unless otherwise specified or there is a logical conflict, the terminology and / or descriptions between different embodiments are consistent and can be mutually referenced. Technical features in different embodiments can be combined to form new embodiments based on their inherent logical relationships. The following descriptions of the embodiments of this application do not constitute a limitation on the scope of protection of this application.

[0094] To facilitate understanding of the technical solutions of the embodiments of this application, the technical terms and related technical solutions in this application will be described below in conjunction with the accompanying drawings.

[0095] 1. Basic Services Set (BSS):

[0096] A Base Service Set (BSS) is a fundamental module of a Wireless Local Area Network (WLAN) that supports relevant standards of the Institute of Electrical and Electronics Engineers (IEEE). It consists of several stations (STAs). Based on the topology of its member STAs and the functions of the BSS, BSSs can be divided into Infrastructure Basic Service Sets (Infrastructure BSSs) and Independent Basic Service Sets (IBSSs).

[0097] Referring to Figure 1(a), the Infrastructure BSS includes a special site that acts as the access distribution system (DS). This site is called the access point (AP), and the other sites are called non-AP sites (non-AP STAs). All non-AP sites must access the DS through the AP (i.e., non-AP sites need to be associated with the AP), and non-AP sites cannot communicate directly with each other by default. For ease of description, the sites in the Infrastructure BSS mentioned in the following embodiments of this application can refer to either APs or non-AP sites.

[0098] 2. Transmission opportunity (TXOP):

[0099] The IEEE 802.11 standard specifies that information transmitted in WLAN over the air interface (wireless medium) is in the form of Physical Layer Protocol Data Units (PPDUs). Clearly, the longer the PPDU, the greater the amount of information it carries, but simultaneously, the greater the possibility that the PPDU cannot be accurately received, and the lower its reliability. Due to environmental uncertainties, the bits in the PPDU may err during transmission. The more bits transmitted at once, the more likely erroneous bits are, making correct decomposition more difficult, or even impossible. When a PPDU cannot be correctly decompressed, it means that the longer the PPDU, the more air interface resources are wasted. Therefore, to balance information capacity and reliability for more efficient transmission, the length of the PPDU is limited. Current standards clearly define the maximum length of the PPDU.

[0100] Typically, the length of a single PPDU is insufficient to meet traffic demands; that is, a device needs to transmit multiple PPDUs to complete a single service interaction. If carrier sense multiple access (CSMA) / collision avoidance (CA) is required for each PPDU transmission, transmission efficiency will be low. Therefore, TXOP was introduced to improve transmission efficiency.

[0101] Referring to Figure 1(b), when device (STA1) has a service transmission requirement, it is considered to have obtained a transmission time, i.e., a TXOP, after completing the backoff through the CSMA / CA mechanism. During this time, device (STA1) can transmit multiple PPDUs as needed. The time interval between adjacent PPDUs (received PPDU and transmitted PPDU, or transmitted PPDU and transmitted PPDU) is only a short inter-frame space (SIFS), saving the device time spent on backoff. When other devices (STA3, STA4) detect a TXOP, they will parse the duration of the TXOP and will not compete for the channel during the TXOP duration, avoiding interference to device (STA1) that has obtained the TXOP. This is called "TXOP protection".

[0102] The device that acquires a TXOP by avoiding contention is called the TXOP holder, and the station that communicates with the TXOP holder within the TXOP is called the TXOP responder. The introduction of TXOPs enables devices in need to use the channel reliably and efficiently.

[0103] 3. Main channel access

[0104] Due to historical reasons, the large-bandwidth channels used by 802.11 devices (devices that use the 802.11 protocol for wireless communication) are logically divided into several sub-channels in 20MHz units. For example, an 80MHz channel has four 20MHz sub-channels, and a 160MHz channel has eight 20MHz sub-channels. Among these sub-channels, the device knows which sub-channel is the primary channel based on the BSS configuration information, and the remaining sub-channels are non-primary channels, as shown in Figure 2(a). In this application embodiment, unless the bandwidth is explicitly specified, the primary channel is referred to as the "primary 20MHz channel," the sub-channel as "a certain 20MHz sub-channel," and the non-primary channel as "a certain 20MHz sub-channel that is not the primary 20MHz channel."

[0105] The main channel plays a crucial role in 802.11 protocol communication. In the aforementioned CSMA / CA mechanism, the device needs to determine whether the channel is idle, and a large part of the basis for this determination comes from the status of the main channel. The device needs to perform energy detection (ED) on each sub-channel and preamble detection (PD) on the main channel. ED has lower hardware requirements but lower accuracy. PD detects the presence of wireless fidelity (WiFi) signals more accurately but has higher hardware requirements. PD detects the presence of PPDUs in the air interface based on the characteristics of WiFi signals and decodes them after capturing them to extract necessary information. For example, necessary information includes the duration field. The duration field indicates how long it will take for frame interaction to complete after the PPDU. The duration field of the first frame of the TXOP can be used to help indicate the length of the TXOP. The structural diagram of the duration field in the PPDU physical layer header can be seen in Figure 2(b).

[0106] For example, the "length of TXOP" is the "length of the PPDU containing the first frame of TXOP" plus the "length indicated by the duration field of the first frame of TXOP". The length of PPDU is specified in the physical layer (PHY) header information.

[0107] The protocol requires PD (Power Distribution) to be performed on the primary channel, and sets the corresponding network allocation vector (NAV) timer using the duration field decoded from the primary channel. Devices are not allowed to compete for the channel before the NAV timer finishes its countdown, which is the aforementioned "TXOP protection" mechanism. Considering the complexity of PD implementation, the protocol does not require sites to perform PD on channels other than the primary channel or outside the operating bandwidth. Currently, "performing PD on the primary channel" is referred to as "primary channel access."

[0108] 4. Non-primary channel access (NPCA)

[0109] NPCA is an operation performed by an AP or non-AP site to increase channel utilization after the TXOP of the primary channel is seized by the OBSS (or for other reasons at least one party occupies the primary channel while the other party can access the non-primary channel, and the start and end time of communication can be determined, such as the periodic in-device non-wifi interference of the AP).

[0110] While the main channel access mechanism is logically sound and simple to operate, its spectrum usage frequency decreases as equipment deployment becomes denser and bandwidth increases. For example, if a 160MHz site detects only its main 20MHz channel as busy, while all other sub-channels are detected as idle, the main channel access mechanism would require the device to back off from using any channels. However, in reality, the other sub-channels are idle and theoretically usable. Therefore, a proposed solution is to transmit via idle non-main sub-channels when the main channel is busy, without backoff. In this case, the device (i.e., the site) switches to the NPCA main channel (only one NPCA main channel is defined within a BSS) and competes for the channel using PD on this non-main channel, as shown in Figure 3(a).

[0111] Non-primary channel access mechanisms can be used in infrastructure BSSs. For example, if an AP and a non-AP STA in BSS1 detect an OBSS TXOP on the primary channel (e.g., a TXOP on BSS2), they can both switch to a non-primary channel for communication (i.e., perform PD on that non-primary channel to compete for the channel). For non-AP sites within an infrastructure BSS, the non-primary channel access mechanism can only be used when an OBSS TXOP is detected on the primary channel, as shown in Figure 3(b). If an OBSS TXOP is detected on the primary channel, it means that the AP of this BSS is participating in the transmission of this BSS site. At this time, even if a site not participating in the transmission switches to a non-primary channel, it cannot communicate with the AP.

[0112] In the currently discussed non-master channel access modes, considering the compatibility of legacy devices (referring to previous generations of WiFi protocol devices) and NAV settings, mainstream designs require that the device only uses the anchor channel for transmission when it detects that the master channel is busy, and jumps back to the master channel from the non-master channel before the master channel becomes idle again (i.e., before the master channel NAV countdown ends). As shown in Figure 3(b).

[0113] 5. Medium Access Recovery Process

[0114] Current standards stipulate that when one station in a nonsimultaneous transmit and receive (NSTR) link is transmitting, another station may lose media synchronization (i.e., air interface synchronization) under certain circumstances. This loss of media synchronization can also be referred to as a "blind state." Similarly, in an enhanced multi-link-single-radio (EMLSR) mode using Multicast Listener Discover (MLD), when one station is transmitting or receiving, other stations in the same EMLSR link set may lose media synchronization under certain circumstances. The reason for this loss of media synchronization is that the station cannot perform Clear Channel Assessment (CCA) and is unaware of whether other stations are transmitting on its operating channel. Therefore, it cannot rashly transmit data, otherwise it will interfere with the current transmission (if any). Currently, when the duration of inability to perform CCA / receive exceeds the media synchronization threshold (aMediumSyncThreshold), a Medium Access Recovery procedure is deemed necessary. aMediumSyncThreshold can be 72 microseconds.

[0115] According to existing standards, at the start of the Medium Access Recovery procedure, the station must set the MediumSyncDelay timer and begin a countdown based on the most recent relevant instruction from the AP. During the countdown, if the station receives a MAC protocol data unit (MPDU) or a PPDU whose TX_DURATION is not UNSPECIFIED, the countdown is immediately reset to zero. While the MediumSyncDelay timer is non-zero, the threshold for the station to perform CCA on the primary channel must be adjusted to dot11MSDOFDMEDthreshold. The number of times the station attempts to initiate a TXOP must not exceed dot11MSDTXOPMax, and each attempt must be initiated via a request-to-send (RTS) frame; otherwise, the station must continue performing CCA until the countdown ends before it can initiate transmission. If the blind state duration is shorter than aMediumSyncThreshold, the STA can choose not to start the MediumSyncDelay timer.

[0116] 6. Site switching delay and switch-back delay

[0117] When a site switches to a channel other than its current operating channel, it takes a certain amount of time to stabilize and begin normal transmission and reception on the new channel. This time is called the switching delay. In Dynamic Sub-band Operation (DSO), at the start of TXOP, the AP needs to allocate sufficient time for non-AP sites to complete the switch, based on their switching delays. Current solutions for achieving this include: the AP adding sufficient padding to the initial DSO frame to allow non-AP sites to complete the switch during the padding period; or the AP prioritizing non-AP sites without DSO functionality (i.e., sites that do not switch operating channels) and then prioritizing non-AP sites with longer switching delays, etc.

[0118] In reality, when a station ends a TXOP, it also needs a handover delay (which can be referred to as "handover delay") to switch back to its original working channel. If the DSO does not consider this, each non-AP station will stabilize on the main channel at different times after the TXOP ends. That is, each non-AP station will start competing for the new TXOP at different times after the TXOP ends, which may lead to fairness issues. Figure 4(a) shows a schematic diagram of the start time of channel competition for different non-AP stations caused by the handover delay in the DSO.

[0119] Furthermore, if a new TXOP begins before a non-AP site completes its handover, that non-AP site misses the duration information of the new TXOP and loses synchronization with the air interface (wireless medium), thus failing to access the channel normally. Figure 4(b) illustrates a non-AP site with a large handover delay in DSO that loses media synchronization. NPCA, Dynamic Power Save (DPS), and DSO all involve switch delay and switch-back delay.

[0120] 7. Dynamic Power Save (DPS):

[0121] DPS mode can be understood as an energy-saving mechanism that dynamically adjusts the capability configuration of WiFi devices according to changes in functional requirements, avoiding unnecessary power consumption.

[0122] Typically, the functional requirements of WiFi devices in different application scenarios change dynamically over time. At any given moment, it is sufficient to ensure that the WiFi device's capability configuration meets these functional requirements. If the WiFi device's capability configuration remains constant, in order to consistently meet dynamically changing functional requirements, the WiFi device needs to employ a higher capability configuration, which implies higher power consumption.

[0123] In DPS mode, WiFi devices operate in two modes: low-capability mode / low-power mode and high-capability mode / high-power mode / data transmission mode. Low-capability mode uses a lower number of spatial streams (NSS) and modulation and coding scheme (MCS) to reduce power consumption. High-capability mode uses higher NSS and MCS. Based on DPS mode, WiFi devices configure lower NSS and MCS in low-capability mode and then adjust and increase NSS and MCS when switching to high-capability mode.

[0124] For example, the IEEE 802.11be standard reduces the NSS and MCS in the low-capability mode of Enhanced Multi-Link Single Radio (EMLSR), using a lower capability configuration; then, it adjusts and increases the NSS and MCS when entering high-capability mode. If the switch from low-capability mode to high-capability mode involves bandwidth adjustment, a phase-locked loop (PLL) needs to generate a new clock and wait for the clock to stabilize, which takes a considerable amount of time. Because the 802.11be standard does not have a design delay to allow the clock switch to complete for bandwidth adjustment, it does not support bandwidth adjustment within the TXOP (Turn-Turn-Out) period.

[0125] To enable the STA to use lower bandwidth in low-capability mode and then increase the bandwidth after switching to high-capability mode, the current solution is to add a MAC padding field to the end of the initial control frame sent by the AP, as shown in Figure 5(a). The duration of the padding field covers the time required for the PLL to generate the corresponding clock and wait for the clock to stabilize, i.e., it covers the STA bandwidth switching time (switch delay), and the channel is reserved during the STA bandwidth switching. After the STA completes the bandwidth switching, it performs Clear Channel Assessment (CCA) and replies with the initial control response frame.

[0126] When switching between different capability configuration states or different energy-saving modes, a uniform latency setting may introduce unnecessary handover delays, making dynamic capability configuration adjustments untimely. When considering handover latency settings, it is necessary to ensure the completion of the capability configuration switch while minimizing the latency to achieve low-latency dynamic capability adjustment. Since bandwidth is uncertain and depends on the channel contention situation of the AP, and the handover time required by the site differs significantly between bandwidth changes and no changes, setting a uniform padding duration in the initial control frame will introduce unnecessary handover delays.

[0127] Based on this, the current padding duration setting is dynamically adjusted according to different scenarios of bandwidth switching and no switching. For example, when bandwidth switching is required during the mode switching process of the target STA, the initial control frame corresponds to a longer padding duration; when the target STA does not compete for the channel or does not require bandwidth switching, the padding duration of the initial control frame is 0, i.e., no padding field is set. When switching between different capability configuration states or between different energy-saving modes, the issue of capability parameter switching will be involved. Adjusting the initial control frame according to different values ​​of each parameter, setting different padding durations based on different parameter combinations for parallel adjustment, and setting fine-grained switching delays for parallel adjustment according to actual conditions can all reduce the adjustment latency in DPS mode.

[0128] As shown in Figure 5(b), for cases with multiple padding duration settings, each STA must first report a padding duration mapping table containing multiple padding duration mapping relationships to the AP during the dynamic power-saving mode capability reporting period. Then, the AP obtains the channel contention results, selects the padding duration corresponding to the specific bandwidth adjustment as the minimum padding duration of the initial control frame, sets the padding length of the ICF, and sends the ICF. The actual padding duration corresponding to the initial control frame should be greater than or equal to the duration indicated in the mapping relationship, thereby ensuring that the STA can complete the capability parameter switching within the padding duration corresponding to the initial control frame.

[0129] 8. Dynamic sub-band operation (DSO):

[0130] As WiFi technology evolves, the operating bandwidth of devices increases significantly. Based on practical experience, the technological advancement of access points (APs) is faster than that of STAs (Stations). This means that while APs increase their operating bandwidth with technological advancements, STAs often retain their lower bandwidth. Furthermore, some network service providers (BSS) may connect to many low-bandwidth, low-power devices, such as IoT devices. These BSSs are characterized by high-bandwidth (e.g., 160MHz, 320MHz) APs connected to many low-bandwidth (e.g., 20MHz, 40MHz, 80MHz) STAs.

[0131] To improve channel utilization of high-bandwidth access points (APs), the protocol introduces the concept of Distributed Subchannel Allocation (DSO). At the start of a TXOP (Turn-Off-Package), the AP can remove a Station (STA) from its operational channel. Within the TXOP, the AP and STA communicate using the allocated subchannel. At the end of the TXOP, the AP switches the STA back to its previous operational channel. The "dynamic" aspect of DSO indicates that the allocated subchannel is effective only within a single TXOP, allowing the AP greater flexibility in channel allocation.

[0132] Within a TXOP, the AP can indicate a sub-channel to a STA with DSO capability. The AP initiates a transmission to the DSO STA after a sufficient time delay. This delay is designed to ensure the DSO device completes the channel handover (center frequency change), as the DSO STA's PLL generates a new clock frequency and waits for it to lock until the clock stabilizes, which takes a considerable amount of time. The AP also ensures the channel is reserved during this handover. At the end of the TXOP, the DSO STA switches back to the primary channel.

[0133] For example, referring to Figure 6(a), the AP divides the bandwidth into two resource units (RUs): 160S and 160P. The AP can reserve a sub-channel during the target STA's (STA1) channel handover by adding a media access control (MAC) padding field to the end of the initial control frame (ICF). Optionally, after receiving the AP's ICF on its original channel (belonging to 160P), the target STA (STA1) completes the channel handover and, after passing through SIFS, replies with an initial control response frame (ICR) indicating that the sub-channel (belonging to 160S) handover is complete. Additionally, STA2 also receives the ICF and, after passing through SIFS, sends an ICR to the AP, indicating that its occupied sub-channel has not changed (still belonging to 160P). After the data transmission delay (delta), STA1 switches back to its original channel (belonging to 160P) after one SIFS.

[0134] Referring to Figure 6(b), in order to initiate subchannel handover before the MAC padding field begins, a new frame check sequence (FCS)2 can be set before the MAC padding field. FCS2 is set in the user information field of the ICF frame. After receiving the ICF frame, the target STA performs FCS2 verification. If the verification passes, subchannel handover begins, and the subchannel handover is completed using the length of the MAC padding field after FCS2.

[0135] The above method relies on the newly added FCS2. If FCS2 is not added, a dual control frame solution is proposed as shown in Figure 7(a). The AP divides the 160MHz bandwidth into two resource units, 160S and 160P. The AP first sends an initial control frame (ICF) with a MAC padding field on the sub-channel corresponding to 160P. The target STA (STA1) is triggered to initiate sub-channel handover (switching to the sub-channel corresponding to 160S) at the beginning of the MAC padding field of the initial control frame, and FCS verification after the MAC padding field is no longer performed. STA1 does not need to reply to the initial control frame. After the initial control frame is sent and a SIFS interval has elapsed, the AP sends a second control frame. The second control frame is used to solicit a response frame from the target STA (STA1) after the handover from the new RU. If the AP receives the response frame, it confirms that the target STA has completed the DSO sub-channel handover. After a delay (delta) due to data transmission, STA1 switches back to its original sub-channel (belonging to 160P) after one SIFS interval. In addition, STA2, which does not perform sub-channel switching, uses the sub-channel belonging to 160P to receive the AP's ICF and second control frame, and replies to the AP with ICR indicating that STA2's sub-channel belongs to 160P.

[0136] The above methods all reserve subchannels during subchannel handover by setting a MAC padding field. The length of the MAC padding field can cover the time required for subchannel handover, but setting the MAC padding field reduces channel utilization efficiency. Therefore, a new method is proposed to reduce the length of the MAC padding field. This involves classifying target STAs, with the AP first communicating with target STAs with shorter subchannel handover times, and then communicating with target STAs with longer subchannel handover times, as shown in Figure 7(b). The AP sends an ICF with padding to STAs 1 to 7, and after one SIFS, receives the ICRs from STAs 1 to 4 with shorter subchannel handover times. After receiving the ICRs from STAs 1 to 4, it receives the ICRs from STAs 5 to 7 with longer subchannel handover times after one SIFS. Thus, when setting the MAC padding field, it is only necessary to ensure that the length of the MAC padding field covers the subchannel handover time required by the target STA with the shorter subchannel handover time. Target STAs with shorter subchannel handover times normally reply with an initial control response frame after completing the subchannel handover; target STAs with longer subchannel handover times do not need to reply with an initial control response frame after completing the subchannel handover.

[0137] When a station switches to a channel other than its current operating channel, it takes a certain amount of time to stabilize and resume normal transmission and reception on the new channel. This time is called the switching delay. In the DSO technology described above, the target STA sends a switching time to the AP to account for the time required for the target STA to switch sub-channels. This time is used by the AP to determine the length of the MAC padding field or to determine the data transmission duration with other STAs that are not switching sub-channels. In other words, the AP prioritizes scheduling stations that do not switch operating channels and then schedules non-AP stations with longer switching delays.

[0138] However, referring to Figure 4(a), during the process of DSO STAs (STA2, STA3, and STA4) switching back to the main channel or their original operating channel at the end of the TXOP, there is also a sub-channel switching delay (denoted as switchback delay or return-to-switch delay). In the current DSO mode, each DSO STA switches back to the main channel according to its corresponding return-to-switch delay. Therefore, the time when different DSO STAs stabilize on the main channel may be inconsistent. That is, the time when each DSO STA starts competing for the new TXOP on the main channel is different, which can easily cause fairness issues.

[0139] Referring to Figure 4(b), if a new TXOP starts before a DSO STA (STA4) switches back to the main channel and stabilizes, the DSO STA will miss the duration information of the TXOP, which will cause the DSO STA to lose synchronization of the air interface (radio medium) and be unable to access the channel normally, while the other DSO STAs (STA2 and STA3) can access the channel normally.

[0140] A novel channel reservation method has been proposed to avoid the use of MAC padding fields. Specifically, during the subchannel handover of the target STA, the AP serves other STAs, transmitting downlink data to those STAs not undergoing subchannel handover. This new channel reservation method improves channel utilization efficiency during the target STA's subchannel handover. As shown in Figure 4(c), after receiving the AP's wake-up notification PPDU1, the target STA (STA2) carries the data sent to STA1 in PPDU1. It can reply with an acknowledgment frame (ACK) on the original channel to confirm the valid reception of the wake-up notification. Then, the target STA initiates subchannel handover, and the AP carries the data sent to STA2 in PPDU2. Alternatively, the step of the target STA replying with the initial control response frame can be omitted. Omitting the acknowledgment step cannot guarantee the valid reception of the initial control frame, which may affect subsequent data transmission. The method of the AP serving other sites during subchannel handover both preserves the channel and improves the channel utilization efficiency of other sites.

[0141] 9. In-Device Coexistence (IDC) Interference

[0142] IDC (Internet Data Center) refers to the operation of other protocols within the device that cause the WiFi of a STA or AP to be unavailable for a period of time, including both periodic and non-periodic periods. For example, when a STA is in IDC state, it may be unavailable for a specific period of time, and the STA can inform the AP of the unavailable period (i.e., interference duration). Dynamic Unavailability Indication (DUI) or Dynamic Unavailability Operation (DUO) is not limited to unavailability caused by IDC. It can be caused by various interferences or coexistence problems, resulting in the unavailability of a device (AP or STA), some functions, or some sub-channels for a period of time. The unavailability can be indicated to the other end in advance through ICF (Internet Functions) and / or ICR (Interactive Code Response).

[0143] Based on the above explanation of the technical solutions, this application provides several embodiments. The technical solutions of the embodiments in this application can all be used for WLANs based on IEEE-related standards. These IEEE-related standards include: 802.11a / b / g standards, 802.11n standards, 802.11ac standards, 802.11ax standards, 802.11be standards, 802.11bn standards / UHR standards / WiFi8 standards, 802.11ad standards, 802.11ay standards, 802.11bf standards / sensing standards, UWB standards / 802.15 standards, etc., and are not limited thereto.

[0144] The technical solutions of this application embodiment can also be used in wireless local area network systems such as Internet of Things (IoT) networks or Vehicle to X (V2X) networks. Of course, this application embodiment can also be applied to other possible communication systems, such as Universal Mobile Telecommunications System (UMTS), Worldwide Interoperability for Microwave Access (WiMAX) communication systems, and Third Generation Partnership Project (3GPP) communication systems. For example, fourth-generation (4G) systems such as Long Term Evolution (LTE) systems, 5G systems such as New Radio (NR) systems, LTE and 5G hybrid networking systems, non-terrestrial networks (NTN), device-to-device (D2D) communication systems, vehicle to everything (V2X) communication systems, machine-type communication (MTC) systems, or other future communication systems. The communication system can also be a non-3GPP communication system; this is not limited.

[0145] The communication systems described above are merely illustrative examples, and are not limited to those described herein. The communication systems provided in this application do not impose any limitations on the solutions described herein. This will be explained uniformly here and will not be repeated below.

[0146] The WLAN communication system provided in this application embodiment will be described below using Figure 8 as an example.

[0147] Figure 8 is a schematic diagram of a communication system provided in an embodiment of this application. As shown in Figure 8, the communication system may include a first communication device and a second communication device. The first communication device is an access point device; the second communication device is a station device. There may be multiple second communication devices. This application embodiment does not limit the number of second communication devices. The mention of at least one or more devices in the second communication device hereinafter indicates at least one or more second communication devices. One or more access point devices can communicate with one or more station devices, and access point devices can also communicate with one or more other access point devices. Station devices can also communicate with one or more other station devices. It is understood that the first communication device may also be a station device, and the second communication device may be an access point device.

[0148] The aforementioned access point device can be an AP, and the aforementioned site device can be a non-AP STA.

[0149] For example, an AP can be a device that supports multiple WLAN standards, such as the 802.11be standard or future Wi-Fi standards; it can also be a device that supports the 802.11a / b / g, 802.11n, 802.11ac, 802.11ax, 802.11be, 802.11bn / UHR / WiFi8 standards, without limitation.

[0150] For example, an AP can be a terminal device with a Wi-Fi chip, network device, communication server, router, switch, bridge, computer, etc. An AP can also serve as an access point for mobile users to access a wired network, primarily deployed in homes, buildings, and campuses, with a typical coverage radius of tens to hundreds of meters. Of course, it can also be deployed outdoors. An AP acts as a bridge connecting wired and wireless networks, its main function being to connect various wireless network clients together and then connect the wireless network to the Ethernet.

[0151] For example, the STA can be a device that supports multiple WLAN standards such as the 802.11be standard or future Wi-Fi standards; it can also be a device that supports the 802.11a / b / g standard, 802.11n standard, 802.11ac standard, 802.11ax standard, 802.11be standard, 802.11bn standard / UHR standard / WiFi8 standard, without limitation.

[0152] For example, an STA can be a wireless communication chip, a wireless sensor, a wireless communication terminal, a communication server, a router, a switch, a bridge, a computer, etc. For example, an STA can be a mobile phone supporting Wi-Fi communication, a tablet computer supporting Wi-Fi communication, a set-top box supporting Wi-Fi communication, a smart TV supporting Wi-Fi communication, a smart wearable device supporting Wi-Fi communication, an in-vehicle communication device supporting Wi-Fi communication, and a computer supporting Wi-Fi communication, etc., without limitation.

[0153] In some embodiments, in the current NCPA mode, a site needs switching delay and handover delay when switching between the main channel and the NPCA main channel. If a site communicates on the NPCA main channel beyond the busy time of its BSS main channel, the AP can only switch to the main channel after the main channel busy time ends. This will affect the communication performance of traditional STAs or non-AP STAs that only support older versions of the protocol and remain on the main channel during NPCA. It may also lead to the loss of media synchronization (blind state) and further trigger the media synchronization recovery process.

[0154] Based on this, this embodiment provides a communication method in which a first communication device acquires a first moment; the first moment is the end time of the busy time of the first channel, or the first moment is before the end time; the first communication device communicates on the second channel before the first moment; and initiates a switch from the second channel to the first channel at the first moment; wherein the first communication device switches back to the first channel before the duration of the loss of medium synchronization of the first channel reaches the medium synchronization threshold (aMediumSyncThershold).

[0155] In other words, by limiting the first moment when the first communication device switches from the second channel to the first channel, ensuring that the first moment is at or before the end of the busy time of the first channel, the first communication device can switch back to the first channel before the duration of the loss of media synchronization on the first channel reaches the media synchronization threshold. This avoids the problem of the first communication device losing media synchronization (blind state) and further triggering the media synchronization recovery process. Moreover, it avoids affecting the communication performance of traditional STAs that remain on the main channel or non-AP STAs that only support older versions of the protocol. Therefore, this embodiment can improve the communication performance of the site.

[0156] The following description, with reference to the communication system shown in Figure 8 and Figure 9, describes a communication method provided in this embodiment, which may include the following steps:

[0157] S901: The first communication device acquires the first moment; before the first moment, the first communication device communicates on the second channel.

[0158] S902: The first communication device initiates a switch from the second channel to the first channel at the first moment; wherein, the first communication device switches back to the first channel before the duration of the loss of medium synchronization on the first channel reaches the medium synchronization threshold (aMediumSyncThershold).

[0159] In this embodiment, the first or second channel can be a wireless channel, i.e., a channel for wireless transmission of signal / data signals in a communication system. Specifically, it can be a channel in a certain radio frequency band, such as a licensed Wi-Fi band, such as a 2.4GHz licensed band, a 5.5GHz licensed band, or a newly defined licensed band in the future; there are no specific limitations. That is to say, at least two of the above-mentioned channels can be located in the same radio frequency band. The channels can be divided according to the frequency domain resources in the radio frequency band. For example, in the 5.5GHz licensed band, each channel can be divided according to a certain bandwidth, such as 80M, 160M, or 320M of bandwidth as one channel, i.e., the bandwidth of the channels is the same. Taking 80M as an example, the bandwidth of 5.46GHz-5.54GHz is channel #1, the bandwidth of 5.54GHz-5.62GHz is channel #2, the bandwidth of 5.62GHz-5.7GHz is channel #3, and so on. Alternatively, the channel bandwidth can also be different. For example, 80MHz bandwidth in the 5.46GHz-5.54GHz range could be channel #1, and 160MHz bandwidth in the 5.54GHz-5.7GHz range could be channel #2, etc. The specific allocation can be defined or pre-configured by the protocol, determined by the first communication device itself, or determined through negotiation between the first communication device and other communication devices (such as the second communication device). There are no specific restrictions. For example, in NPCA mode, the first channel could be the main channel in the BSS where the first communication device is located, i.e., the main channel through which the first communication device operates, and the second channel could be the NPCA main channel in the BSS where the first communication device is located. As another example, in DPS mode, the first channel could be the channel with the first bandwidth when the first communication device operates in high-capacity mode, and the second channel could be the channel with the second bandwidth when the first communication device operates in low-capacity mode.

[0160] The busy time of the first channel can refer to the duration of the TXOP of the main channel, which is the TXOP that was preempted by OBSS; or the duration of the first channel being occupied for other reasons.

[0161] Taking NPCA mode as an example, during the busy period of the first channel (main channel), the first communication device AP and the second communication device can switch to the second channel (NPCA main channel) for communication; after the first channel is busy, the first communication device and the second communication device can switch back to the first channel for communication. In order to ensure the communication performance of the first communication device and the second communication device, it is very important to know the first moment when the first communication device starts to switch back to the first channel and the second moment when the second communication device starts to switch back to the first channel.

[0162] Assume the first communication device can be an AP, and the second communication device is some or all of the STAs associated with the AP, or a specific STA; STAs can represent some or all of the STAs associated with the AP; the first and second communication devices communicate through a first channel and / or a second channel. In one possible design, the second time can be the first time; that is, the first and second communication devices start switching from the second channel to the first channel together, as shown in Figure 10(a). In another possible design, the second time can be the first time delayed by a preset duration; that is, the second communication device can start switching from the second channel to the first channel after a preset duration compared to the first communication device, as shown in Figure 10(b); the preset duration is not limited and can be customized according to the actual application. The AP and STA switching back together, or the AP switching back to the second channel before the STA, ensures that the STA can access the associated AP after switching back to the first channel.

[0163] The value at the first moment can include, but is not limited to, the following schemes:

[0164] In one possible design, the first moment is the end of the busy period of the first channel. The first communication device can begin switching from the second channel to the first channel at the end of the busy period of the first channel. For example, the AP and / or STAs start switching from the NPCA main channel to the main channel together at the end of the TXOP, or the STAs start switching from the NPCA main channel to the main channel after a preset time delay from the end of the TXOP.

[0165] In one possible design, the first moment can be before the end of the busy time of the first channel, and the first moment can be determined based on the target moment.

[0166] 1. The first time can be the target time T1. The AP and / or STAs can initiate the handover from the second channel to the first channel at the target time T1, or the STAs can initiate the handover from the second channel to the first channel after a preset time delay from the target time T1.

[0167] 2. The first time interval is before the target time interval T1, and the duration between the first time interval and the target time interval is less than the duration required to complete one frame interaction on the second channel. For example, if the AP and / or STAs can detect the time interval of the target time interval T1 when obtaining the TXOP of the second channel, or before the end of the busy time of the main channel, or when back off to 0, or when completing each frame interaction; if this time interval is greater than or equal to the time to complete one frame interaction (such as the time of one shortest frame interaction), then frame interaction continues on the second channel, and the AP is guaranteed to initiate the handover from the first channel to the second channel at or before the target time. If this time interval is less than the time to complete one frame interaction (such as the time of one shortest frame interaction), the AP and STAs stop frame interaction on the second channel. In this scenario, the AP performing the detection can switch immediately or at the target time; the STA performing the detection can switch immediately, at the target time, or before the target time, when the duration of frame interaction on the second channel reaches a duration threshold; the duration threshold is not limited and can be customized according to the actual application; this duration threshold can be predefined or placed in the NPCA element, negotiated or indicated during the capability negotiation or update phase. Frame interaction in this embodiment can refer to a single frame interaction or multiple frame interactions; frame interaction can refer to the process of devices sending frames and providing feedback on those frames.

[0168] Furthermore, the target time can be determined based on at least one of the following: the busy time of the first channel, the switchback delay of the first communication device, the switchback delay of the second communication device, and aMediumSyncThershold. The target time is the time corresponding to a target duration preceding the end of the busy time of the first channel. The value of the target duration can be, but is not limited to, any of the following:

[0169] (1) The target duration is the switchback delay of the first communication device. The first communication device begins switching from the second channel to the first channel before the end of the busy time of the first channel. For example, the AP and / or STAs begin switching from the NPCA main channel to the main channel before the end of the TXOP (Turn-Off Point) time; or the STAs delay by a preset time after the AP. Therefore, the AP can switch back to the second channel before or at the end of the busy time of the first channel, which can avoid media synchronization loss and will not affect the communication performance of the stations remaining on the first channel. If the AP switches back to the first channel in advance or the STAs switch back to the first channel simultaneously in advance, the AP will stabilize on the first channel in advance, which can enable the STAs to stabilize quickly after switching back, thus improving the communication performance of the stations in the system.

[0170] (2) The target duration is the difference between the switchback delay of the second communication device and aMediumSyncThershold. Optionally, the switchback delay of the second communication device can be the maximum, minimum, or average value of the switchback delay of all or some STAs, as shown in Figure 11(b). For example, based on a grace period for the value of aMediumSyncThershold after the TXOP ends, the STAs begin switching from the NPCA main channel to the main channel ahead of the maximum value of the STAs' switchback delay; here, the STAs can be some of the STAs associated with the AP, that is, some STAs can be allowed to experience media synchronization loss.

[0171] (3) The first time can also be selected from the earlier of the target times in (1) and (2) above; that is, if the switchback delay of the first communication device is greater than or equal to the difference between the switchback delay of the second communication device and aMediumSyncThershold, then the target duration is the switchback delay of the first communication device; if the switchback delay of the first communication device is less than the difference between the switchback delay of the second communication device and aMediumSyncThershold, then the target duration is the difference between the switchback delay of the second communication device and aMediumSyncThershold; the switchback delay of the second communication device is the maximum, minimum or average of the switchback delays of all or some of the devices in the second communication device. For example, relative to the end time of TXOP, the AP starts switching from the NPCA main channel to the main channel a time earlier than max(AP's switch back delay, STA's switch back delay-aMediumSyncThershold). If the AP and some STAs switch to the first channel in advance, the AP can ensure that it switches back before the end time of TXOP to avoid media loss, and the STA can ensure that it does not enter the media synchronization recovery process after switching back to the first channel.

[0172] (4) The target duration is the switchback delay of the second communication device. Optionally, the switchback delay of the second communication device can be the maximum, minimum, or average of the switchback delays of all or some STAs. For example, the AP and / or STAs start switching from the NPCA main channel to the main channel before the maximum of the switchback delays of all STAs at the end of TXOP; as shown in Figure 11(a). This allows some STAs to switch to the first channel earlier, avoiding media synchronization loss. There is no restriction on the time for other STAs to switch to the first channel, allowing media synchronization loss to occur.

[0173] In addition, the second time point is the time corresponding to the switchback delay of the second communication device, which is earlier than the end of the busy time of the first channel. That is, STAs can start switching from the NPCA main channel to the main channel in advance of their respective switchback delays. This ensures that they can switch back to the main channel when the busy time of the main channel ends, avoiding the occurrence of blind states.

[0174] In one possible design, the first moment is the moment when the duration for which the first communication device stops frame interaction on the second channel reaches a duration threshold. That is, if no frame interaction occurs on the second channel for a certain period of time, both the AP and STAs can immediately switch from the second channel to the first channel.

[0175] The aforementioned method of switching from the second channel to the first channel is not limited to NPCA mode, but can also be applied to DPS mode, DSO mode, IDC or DUI or DUO mode, or new features and scenarios in next-generation WiFi. In these features, because sub-channel switching or bandwidth switching requires latency, APs and / or STAs switch from the first channel to the second channel in advance (early back-switch) to avoid loss of media synchronization. More importantly, early back-switch by the AP can prevent late AP back-switch from impacting the performance of legacy STAs (those that remain on the main channel or in DPS scenarios that do not support dynamic power saving) or non-AP STAs that only support older protocol versions (not supporting WiFi 8 NPCA, DSO, DPS, IDC or DUI or DUO modes).

[0176] In one possible design, the first communication device sends a handover instruction to at least one of the second communication devices. The handover instruction is used to instruct the second communication device to initiate a handover from the second channel to the first channel at a second time.

[0177] The handover instruction information includes the AID of at least one device. For example, it instructs some STAs to switch to the first channel in advance, so that when the STA performs NPCA operation, it will switch from the NPCA main channel to the main channel in advance to avoid media synchronization loss, or help other STAs that have lost media synchronization to restore media synchronization.

[0178] Restricting the handover time from the second channel to the first channel for only a portion of STAs (early handover) is not limited to NPCA mode, but can also be applied to DPS mode, DSO mode, or new features in next-generation WiFi to address scenarios where media synchronization loss may occur. Accordingly, the AID of some STAs that prematurely handover is reflected in the DPS / DSO mode elements of the downlink frames during the DPS / DSO mode capability negotiation or update phase. The update phase is not restricted and can be either a capability update phase or an operating parameter update phase.

[0179] Optionally, the switching indication information is carried in the downlink frame sent during the capability negotiation phase or update phase of the target mode; the target mode is any of the following: NPCA mode, DPS mode, DSO mode, IDC or DUI or DUO mode.

[0180] Optionally, the uplink frame may be at least one of the following: an association request frame, or a reassociation request frame, a target mode enable frame, a target mode notification frame, or a target mode dedicated management frame; the downlink frame may be at least one of the following: a beacon frame, a data pending transmission indication message, a beacon frame or a transmission indication mapping frame, or a target mode dedicated management frame. It is understood that the uplink and downlink frames may also be other frames containing elements of the target mode.

[0181] For example, during the NPCA capability negotiation or update phase:

[0182] Downlink frames may be: association request frames, reassociation request frames, NPCA mode enable frames, NPCA mode notification frames, NPCA dedicated management frames, or other frames containing NPCA elements; downlink frames may be: beacon frames, delivery traffic indication message (DTIM) beacon frames or traffic indication map (TIM) frames, NPCA dedicated management frames, or other broadcast, multicast, or unicast frames containing NPCA elements or NPCA parameters.

[0183] Optionally, the site device may report capability information through an association request frame, a reassociation request frame, an NPCA mode enable frame, an NPCA mode notification frame, or other frames. The reported content may be included in the basic NPCA element in the (re)association request frame, the NPCA parameter field in the NPCA mode enable frame, the NPCA parameter update field in the NPCA mode notification frame, or other fields in these frames, or other frames containing NPCA elements.

[0184] DPS capability negotiation or update phase:

[0185] Uplink frames may be: association request frames, reassociation request frames, DPS mode enable frames, DPS mode notification frames, DPS dedicated management frames, or other frames containing DPS elements; downlink frames may be: beacon frames, delivery traffic indication message (DTIM) beacon frames or traffic indication map (TIM) frames, DPS dedicated management frames, or other broadcast, multicast, or unicast frames containing DPS elements or DPS parameters.

[0186] Optionally, the site device may report capability information through an association request frame, a reassociation request frame, a DPS mode enable frame, a DPS mode notification frame, or other frames. The reported content may be included in the basic DPS element in the (re)association request frame, the DPS parameter field in the DPS mode enable frame, the DPS parameter update field in the DSO mode notification frame, or other fields in these frames or other frames containing DPS elements.

[0187] DSO capability negotiation or update phase:

[0188] Uplink frames may be: association request frames, reassociation request frames, DSO mode enable frames, DSO mode notification frames, DSO dedicated management frames, or other frames containing DSO elements; downlink frames may be: beacon frames, delivery traffic indication message (DTIM) beacon frames or traffic indication map (TIM) frames, DSO dedicated management frames, or other broadcast, multicast, or unicast frames containing DSO elements or DSO parameters.

[0189] Optionally, the site can report capability information through an association request frame, a reassociation request frame, a DSO mode enable frame, a DSO mode notification frame, or other frames. The reported content can be included in the basic DSO element in the (re)association request frame, the DSO parameter field in the DSO mode enable frame, the DSO parameter update field in the DSO mode notification frame, or other fields in these frames or other frames containing DSO elements.

[0190] In summary, this embodiment limits the first moment when the first communication device switches from the second channel to the first channel, ensuring that the first moment is at or before the end of the busy time of the first channel. This allows the first communication device to switch back to the first channel before the duration of the loss of media synchronization on the first channel reaches the media synchronization threshold, thus avoiding the problem of the first communication device losing media synchronization (blind state) and further triggering the media synchronization recovery process. Moreover, it avoids affecting the communication performance of traditional STAs that remain on the main channel or non-AP STAs that only support older versions of the protocol. Therefore, this embodiment can improve the communication performance of the site.

[0191] In some embodiments, in the current NCPA mode, if a station switches to the NPCA main channel during the busy time of its BSS main channel and returns to the main channel for communication after the busy time ends, the station may need to switch back to the main channel after switching to the NPCA main channel, which not only consumes a lot of resources but may also affect communication performance.

[0192] Based on this, this embodiment provides a communication method in which a first communication device switches from a first channel to a second channel when channel switching conditions are met. The channel switching conditions include: the duration of the first communication device's stay on the second channel is greater than or equal to the duration required for the first communication device to access the second channel and perform frame interaction on the second channel; or, the busy duration of the first channel is greater than or equal to a duration threshold. Within the busy duration of the first channel, the first communication device can complete the switch from the first channel to the second channel, as well as access the second channel and perform frame interaction on the second channel. Switching from the first channel to the second channel only occurs when the duration of the first communication device's stay on the second channel is greater than or equal to the duration required for the first communication device to access the second channel and perform frame interaction on the second channel, or when the first communication device can complete the switch from the first channel to the second channel, as well as access the second channel and perform frame interaction on the second channel, within the busy duration of the first channel. This ensures that the first communication device can perform beneficial communication on the second channel, improving communication performance.

[0193] It is understood that the communication method described in this embodiment only limits the channel switching conditions from the first channel to the second channel, and does not restrict the steps before and after it. For example, the conditions for switching from the second channel to the first channel can be unrestricted, and it can be implemented independently or before the communication method described in FIG9. For example, as shown in FIG12, step S900, when the channel switching conditions are met, switches from the first channel to the second channel, and is implemented before steps S901 and S902.

[0194] The following describes another communication method provided by an embodiment of this application, with reference to the communication system shown in Figure 8. The method may include the following steps:

[0195] S900: When the channel switching conditions are met, the first communication device switches from the first channel to the second channel.

[0196] In one possible design, the conditions for satisfying channel switching may include: the duration of the first communication device's stay on the second channel is greater than or equal to the duration required for the first communication device to access the second channel and perform frame interaction on the second channel.

[0197] Optionally, the time required to complete access to the second channel and perform frame interaction on the second channel is determined by at least one of the following: uplink communication, downlink communication, and channel access type. The channel access type can include any of the following: contention, scheduling, AP scheduling only in the first TXOP, AP downlink transmission or AP sending downlink frames, AP contention only in the first TXOP, AP sending the first frame, and a mix of contention and scheduling. Specific descriptions of the channel access types can be found in subsequent embodiments and will not be repeated here. Uplink communication can refer to the STA sending frames to the AP through the second channel; the duration of uplink communication may differ for different STAs or APs and different channels. Downlink communication can refer to the AP sending frames to the STA through the second channel; the duration of downlink communication may differ for different STAs or APs and different channels. That is, the time required to complete access to the second channel and perform frame interaction on the second channel can take different values ​​for uplink and downlink communication, and can also take different values ​​when using different channel access types.

[0198] The dwell time needs to consider the handover delay and switchback delay of APs and / or STAs, the medium synchronization threshold (aMediumSyncThershold), the busy duration of the first channel, etc. The busy duration of the first channel is the time from when the first communication device decides to start switching from the first channel to the second channel to the end of the busy time of the first channel; it can also be the complete busy time of the main channel; or it can be the NPCA duration. For example, it can be the time that OBSS will continue, or the NAV time set by OBSS.

[0199] For example, if the dwell time of the first communication device in the second channel is greater than or equal to the time required for the first communication device to access the second channel and perform frame exchange in the second channel, it can be expressed by equation (1): BSS primary channel busyness duration – T_0 – switch delay ≥ T_comm (1)

[0200] Wherein, BSS primary channel busyness duration can be the busy duration of the first channel; T_comm can be the time required to access the second channel and perform frame exchange on the second channel; switch delay can be the switching delay of the first communication device, which can be any station in the BSS system (stations include AP and STA). Because switch delay is the capability of each station, the switch delay of AP and STA may be different, and the switch delay of different STAs may also be different. The value of T_0 is not limited and can be customized according to the actual application situation, for example, including but not limited to the following situations:

[0201] Optionally, the dwell time is the difference between the busy duration of the first channel and the handover delay of the first communication device; that is, T_0 is 0. In this case, only the handover delay of each station is considered. In NPCA mode, the STAs will switch from the NPCA main channel to the main channel together at the end of TXOP. Alternatively, T_0 can be other constants. This embodiment does not impose any restrictions and can be set according to the actual application.

[0202] Optionally, the dwell time is the difference between the busy duration and the sum of the handover delay and the switchback delay of the first communication device. Assuming the first communication device is an AP, T_0 can be the AP's switchback delay, and the switch delay can be the AP's handover delay. In this case, the AP's handover delay and switchback delay are primarily considered. In an NPCA, the STAs and AP switch from the NPCA main channel together at the target time. Alternatively, assuming the first communication device is a single STA or multiple STAs, T_0 can be the STAs' switchback delay (the maximum, minimum, or average of the switchback delays of some or all STAs), and the switch delay can be the STAs' switchback delay (the maximum, minimum, or average of the switch delays of some or all STAs). That is, it must be ensured that after a STA switches to the NPCA main channel, it can complete at least one frame exchange; and that some or all STAs can switch back to the main channel before losing media synchronization.

[0203] Optionally, the dwell time is the difference between the busy duration and the sum of the handover delay of the first communication device and the switchback delay of the second communication device; that is, T_0 can be the switchback delay of STAs, and the switch delay can be the handover delay of AP; or T_0 can be the switchback delay of AP, and the switch delay can be the handover delay of STAs. A suitable value is selected by comprehensively considering the handover delay and switchback delay of both AP and STAs.

[0204] Optionally, the dwell time is the difference between the sum of the busy duration and aMediumSyncThreshold and the handover delay of the first communication device; that is, based on the handover delay of AP or STAs, the media synchronization threshold aMediumSyncThreshold that triggers the media synchronization recovery process is considered to adjust T_0, thereby adding buffer time.

[0205] Optionally, the dwell time is the difference between the sum of the busy duration and aMediumSyncThreshold and the sum of the handover delay of the first communication device and the handover delay of the second communication device. That is, based on the handover delay and handover delay of the AP or STAs, the media synchronization threshold aMediumSyncThreshold that triggers the media synchronization recovery process is considered to adjust T_0, thereby adding buffer time.

[0206] Optionally, if the first communication device is an AP, and the second communication device is some or all of the STAs associated with the AP; the handover delay of the second communication device is the maximum, minimum, or average of the handover delays of all or some of the STAs in the second communication device; the handover delay of the second device can be the maximum, minimum, or average of the handover delays of all or some of the STAs. For example, the handover delay of the STAs mentioned above can be the handover delay of multiple STAs or the maximum, minimum, or average of the handover delays, or it can be the handover delay of a single STA. Alternatively, if the second communication device is an AP, and the first communication device is some or all of the STAs associated with the AP, the handover delay of the first communication device is the maximum, minimum, or average of the handover delays of all or some of the STAs; the handover delay of the first communication device is the maximum, minimum, or average of the handover delays of all or some of the STAs.

[0207] In one possible design, the conditions for satisfying channel switching may include: the busy duration of the first channel is greater than or equal to a duration threshold, wherein, within the busy duration of the first channel, the first communication device can complete the switching from the first channel to the second channel, and access the second channel and perform frame interaction on the second channel.

[0208] The duration threshold can be determined based on the switching delay and back-to-work delay of the first and second communication devices, and the duration required to access the second channel and perform frame interaction on the second channel.

[0209] For example, the condition for satisfying channel switching can be expressed by the following equation (2): BSS primary channel busyness duration ≥ T_1 (2)

[0210] Where T_1 represents the duration threshold.

[0211] If the first communication device is an AP, and the second communication device is some or all of the STAs associated with the AP; the duration threshold can be, but is not limited to, the following:

[0212] Optionally, the duration threshold is greater than or equal to the sum of the maximum delay and the duration required to access the second channel and perform frame interaction on the second channel; the maximum delay is the maximum sum of the handover delay and the switchback delay in the first and second communication devices. That is, when switching from the first channel to the second channel, the station with the largest handover delay and switchback delay is considered. In NPCA mode, it can be expressed by the following formula (3): T_1≥max[(Switch delay+Switch back delay)of all NPCA STAs]+T_comm (3)

[0213] Where T_comm can be the time required to access the second channel and perform frame exchange on the second channel; NPCA STAs can refer to stations in NPCA mode, including APs and some or all STAs. That is, when switching from the NPCA main channel to the main channel, the station with the largest handover delay and handback delay is considered.

[0214] Optionally, the duration threshold is greater than or equal to the sum of the maximum delay and the time required to access the second channel and perform frame interaction on the second channel; the maximum delay is the maximum value of the handover delay between the first and second communication devices. That is, when switching from one channel to the second channel, the station with the largest handover delay is considered. In NPCA mode, it can be expressed by the following formula (4): T_1≥max[Switch delay of all NPCA STAs]+T_comm (4)

[0215] That is, when switching from the NPCA main channel to the main channel, the station with the largest switching delay is considered.

[0216] Optionally, the duration threshold is greater than or equal to the sum of the maximum delay and the duration required to access the second channel and perform frame interaction on the second channel; the maximum delay is the maximum value of the handover delay between the first and second communication devices. That is, when switching from one channel to the second channel, the station with the largest handover delay is considered.

[0217] However, some STAs may have significant handover and / or switchback delays. To ensure all NPCA STAs complete round-trip handovers and remain on the NPCA main channel for a time equal to or exceeding T_comm to access the channel and perform frame exchange (communication), the range of T_1 will be extremely large. This may prevent some other stations capable of fast handover from switching between NPCA main channels, thus negatively impacting communication performance. One possible design scheme where channel handover is not satisfied includes at least one of the following: the sum of the handover delay and switchback delay in the second communication device is greater than or equal to the difference between a duration threshold and the time required to access the second channel and perform frame exchange on the second channel; or the handover delay or switchback delay in the second communication device is greater than or equal to the difference between a duration threshold and the time required to access the second channel and perform frame exchange on the second channel. Assuming T_1 is indicated or predefined in advance during the capability negotiation or update phase, the protocol can also limit the conditions for not meeting channel switching to "Switch delay + switch back delay ≥ T_1 - T_comm" or "Switch(back) delay ≥ T_1 - T_comm". STAs that do not meet these conditions will not participate in NPCA, or will suspend or disable NPCA mode, meaning they will not switch between the main NPCA channels. Therefore, when using T_1 as a time threshold for determining whether channel switching is necessary, if a channel switching is determined, all NPCA participating stations can complete the switch and remain on the main NPCA channel for a duration equal to or exceeding T_comm. In other words, STAs with longer switching delays will not perform channel switching, ensuring that STAs with shorter switching delays can conduct beneficial communication on the second channel and reducing unnecessary overhead for STAs with longer switching delays.

[0218] Combining the two schemes above, when the first communication device is an AP and the second communication device is some or all of the STAs associated with the AP, the conditions for satisfying the channel handover also include: at least one second communication device satisfies that its dwell time on the second channel is greater than or equal to the time required for the second communication device to access the second channel and perform frame interaction on the second channel. Alternatively, at least one second communication device satisfies that the busy duration of the first channel is greater than or equal to a duration threshold, wherein, within the busy duration of the first channel, the second communication device can complete the handover from the first channel to the second channel, as well as access the second channel and perform frame interaction on the second channel. For example, in NPCA mode, the AP and at least one STA only handover to the NPCA main channel together when the channel handover conditions are met. Channel handover is only meaningful and beneficial communication can only be performed when the AP and at least one STA handover to the second channel together. The above "at least one" can also be "n", that is, the AP and at least n STAs only handover to the NPCA main channel together when the channel handover conditions are met. The value of n can be an integer such as 1, 2, 3, etc. For example, if n is 3, it means that the AP and at least 3 STAs only handover to the NPCA main channel together when the channel handover conditions are met.

[0219] In one possible design, information indicating the time (T_comm) and / or T_0 required to complete access to the second channel and perform frame interaction on the second channel is carried in the uplink or downlink frames negotiated and sent during the target mode capability negotiation or update phase. For example, during the NPCA capability negotiation or update phase, the AP can carry parameters such as T_0 and / or Tcomm, as described in this embodiment, through the NPCA element of the downlink frame; the STA can also carry relevant suggestions through the NPCA element of the uplink frame. The target mode is any one of the following: NPCA mode, DPS mode, DSO mode, IDC or DUI or DUO mode. The explanation of uplink and downlink frames can be found in the above embodiments and will not be repeated here.

[0220] The communication method described in this embodiment can be applied not only to NPCA mode, but also, after the following adjustments, to DPS mode, DSO mode, IDC or DUI or DUO mode, or to new features and scenarios in next-generation WiFi. For example, in IDC, DUI or DUO, the STA will only perform sub-channel switching when the conditions Channel unavailable duration - switch delay - switch back delay ≥ T_comm or Channel unavailable duration - switch delay - T_0 ≥ T_comm are met. Here, Channel unavailable duration represents the duration or duration of channel unavailability. For example, in a DSO or DPS, the remaining TXOP duration after the FCS2 or Intermediate FCS of the Initial Control Frame (ICF) must meet the following conditions before a low-capacity to high-capacity switch or a switch from the main channel to a DSO sub-channel is necessary or permissible: Remaining time in TXOP-switch delay-switch back delay ≥ T_comm or Remaining time in TXOP-switch delay-T_0 ≥ T_comm; where Remaining time in TXOP can represent the remaining duration within the TXOP, or the DSO duration; or the duration between the start of the channel switch at the DSO site and the end of the DSO.

[0221] In summary, switching from the first communication device to the second channel only occurs when the dwell time of the first communication device on the second channel is greater than or equal to the time required for the first communication device to access the second channel and perform frame interaction on the second channel, or when the first communication device can complete the switch from the first channel to the second channel and access the second channel and perform frame interaction within the busy duration of the first channel. This ensures that the first communication device can perform beneficial communication on the second channel and improves communication performance.

[0222] In some embodiments, in NPCA mode, after the AP and NPCA STAs switch from the main channel to the NPCA main channel, the time spent on the NPCA main channel is limited. Channel access using only the enhanced distributed channel access (EDCA) contention method has a high probability of collision. Therefore, how to achieve efficient channel access within a limited time in the case of multiple NPCA STAs is an urgent problem to be solved.

[0223] Based on this, this embodiment provides another communication method: the second communication device acquires channel access indication information; if the channel access indication information indicates that the channel access type of the second communication device is a mixture of scheduling and contention, then based on the busy time of the first channel and the channel access indication information, the current access type of the second channel is synchronized with the first communication device, where the current access type includes waiting for scheduling by the first communication device or participating in contention for the second channel; the second channel is accessed using the current access type. In this embodiment, by using a mixture of scheduling and contention, efficient channel access is achieved within a limited time.

[0224] The communication method described in this embodiment can be implemented in conjunction with the communication methods of the foregoing embodiments. For example, the communication method of this embodiment can be implemented when switching from the first channel to the second channel is met, or before switching from the second channel to the first channel at the first moment. Of course, the communication method of this embodiment can also be implemented independently, and this application does not impose any limitations.

[0225] The following description, with reference to the communication system shown in Figure 8 and Figure 13, describes another communication method provided by an embodiment of this application, which may include the following steps:

[0226] S1301, The second communication device obtains channel access indication information.

[0227] In one possible design, the first communication device sends channel access indication information; correspondingly, the second communication device receives the channel access indication information sent by the first communication device.

[0228] The first communication device is an access point (AP), and the second communication device is some, all, or a single STA associated with the AP. The channel access indication information can indicate the channel access type of the second communication device as any of the following: waiting for scheduling, AP scheduling only within the first TXOP, AP downlink transmission or AP sending downlink frames, AP contention only within the first TXOP, AP sending the first frame, participation in contention and the type of contention, mixed scheduling and contention, and scheduling priority. "AP scheduling only within the first TXOP" can mean that the first TXOP is limited to AP scheduling, and subsequent TXOPs are not restricted to scheduling, allowing STA contention for access; "AP downlink transmission or AP sending downlink frames" can mean that the AP competes for a TXOP for downlink transmission, and the STA does not compete for the TXOP; "AP contention only within the first TXOP" can mean that the AP competes for the first TXOP for downlink transmission or scheduling, and the STA does not compete for the TXOP; subsequent TXOPs are not restricted; "AP sending the first frame" can mean that only the AP sends the first frame, and subsequent frames are not restricted. Optionally, the channel access indication information may also include a busy duration threshold. The specific value of the busy duration threshold is not limited and can be customized according to the actual application, such as being indicated in the NPCA element during the update phase.

[0229] For example, during the capability negotiation or update phase, the AP can decide on the type of channel access and generate channel access indication information. For instance, in the capability negotiation or update phase of NPCA mode, the AP can determine the type of channel access on the NPCA main channel based on the number of sites participating in NPCA mode, the handover delay and handback delay (delay of handing back to the main channel) reported by STAs, and generate channel access indication information. This channel access indication information can then be sent via unicast, broadcast, or multicast.

[0230] In one possible design, the second communication device sends channel access suggestion information to the first communication device, and correspondingly, the first communication device receives the channel access suggestion information sent by the second communication device. Then, the second communication device receives channel access indication information returned by the first communication device based on the access indication suggestion information. The channel access suggestion information can suggest the channel access type for the second communication device as any of the following: scheduling, AP scheduling only in the first TXOP, AP downlink transmission or AP sending downlink frames, AP contention only in the first TXOP, AP sending the first frame, participation in contention and the type of contention, mixed scheduling and contention, and scheduling priority.

[0231] For example, during the capability negotiation or update phase, a STA can also decide its own channel access type and generate channel access recommendation information. For instance, in the capability negotiation or update phase of NPCA mode, a STA can determine its channel access type on the NPCA main channel based on the number of sites participating in NPCA mode, the handover latency and handback latency of each participating STA, and generate channel access recommendation information. It then sends the channel access recommendation information to the AP. After receiving the channel access recommendation information, the AP can directly agree to the STA's recommendation and generate channel access indication information; alternatively, it can generate channel access indication information based on its own decided channel access type combined with the channel access recommendation information.

[0232] In one possible design, the channel access indication information is carried in the downlink frame during the capability negotiation or update phase of the target mode, and the channel access indication suggestion information is carried in the uplink frame during the capability negotiation or update phase of the target mode; the target mode is any one of the following: NPCA mode, DPS mode, DSO mode, IDC or DUI or DUO mode.

[0233] In one possible design, the uplink frame is at least one of the following: an association request frame, or a re-association request frame, a target mode enable frame, a target mode notification frame, or a target mode dedicated management frame; the downlink frame is at least one of the following: a beacon frame, a data pending transmission indication transmission information, a beacon frame or a transmission indication mapping frame, or a target mode dedicated management frame. The relevant descriptions of the uplink and downlink frames can be found in the above embodiments and will not be repeated here.

[0234] In summary, during the capability negotiation or update phase, STAs report their respective handover and handback delays to the AP; the AP broadcasts its own handover and handback delays and those of each STA participating in the NPA mode, and each STA receives the handover and handback delays from each STA participating in the NPA mode.

[0235] S1302. If the channel access indication information indicates that the channel access type of the second communication device is a mixture of scheduling and contention, the second communication device shall synchronize the current access type of the second channel with the first communication device according to the busy time of the first channel and the channel access indication information.

[0236] Accordingly, if the channel access indication information indicates that the channel access type of the second communication device is a mixture of scheduling and contention, the first communication device will synchronize the current access type of the second channel with the second communication device according to the busy time of the first channel and the channel access indication information.

[0237] The current access type includes waiting for the first communication device to schedule or participating in the competition for the second channel; the first channel is the channel through which the first and second communication devices can communicate outside of busy hours.

[0238] In one possible design, the channel access indication information also includes a busy duration threshold. When the busy time of the first channel is greater than or equal to the busy duration threshold, and / or the number of second communication devices switching to the second channel exceeds the quantity threshold, the current access type is waiting for the first communication device to schedule. The specific value of the quantity threshold is not limited and can be set according to actual application conditions. When the busy time of the first channel is less than the busy duration threshold, and / or the number of second communication devices switching to the second channel does not exceed the quantity threshold, the current access type is participating in contention for the second channel. Similarly, the first communication device can also determine the current access type and synchronize with the second communication device. Optionally, the number of second communication devices switching to the second channel is determined based on the busy time of the first channel, the busy duration threshold, or the handover delay and switchback delay of the second communication device. For example, the second communication device and the first communication device can determine the number of second communication devices switching to the second channel based on the handover delay and switchback delay of each STA and the busy time of the first channel, or based on the busy duration threshold and the busy time of the first channel.

[0239] For example, during the NPCA capability negotiation or update phase, the negotiated channel access type is a mix of scheduling and contention. In each subsequent NPCA mode, the AP and STA can dynamically switch the channel access type based on the main channel busy time or the number of stations switching to the NPCA main channel. That is, the AP can determine whether to send scheduling information or not; the STA can determine whether to wait for AP scheduling or participate in contention. For instance, if the current OBSS duration or main channel busy time is greater than or equal to the busy time threshold, the number of stations switching to the NPCA main channel may exceed the threshold. In this case, due to the large number of stations switching to the NPCA main channel, the scheduling mode is switched to, thereby reducing the collision probability of multiple STAs and achieving efficient access for multiple STAs. Conversely, if the current OBSS duration or main channel busy time is less than the busy time threshold, the number of stations switching to the NPCA main channel may not exceed the threshold, and the number of stations switching to the NPCA main channel may be small. In this case, the contention mode is switched to, because with fewer STAs, the collision probability is low, and contention access is more efficient, avoiding the overhead of scheduling.

[0240] S1303, The second communication device uses the current access type to access the second channel.

[0241] In one possible design, if the current access type is waiting for scheduling by the first communication device; the first communication device sends scheduling information to the second device; and the second communication device receives the scheduling information sent by the first communication device.

[0242] In one possible design, if the current access type is to compete for the second channel, then the user can compete for the second channel based on the type of competition. Here, the type of competition can refer to the type of EDCA (Electronic Data Acquisition).

[0243] In conjunction with the above embodiments, after the second communication device obtains the channel access indication information, if the channel access indication information indicates that the channel access type of the second communication device is scheduling priority, then it waits for the scheduling information sent by the first communication device; if the waiting time exceeds the waiting threshold, it begins to participate in the competition for the second channel. This avoids unnecessary overhead and impact on communication performance caused by waiting indefinitely for scheduling information from the first communication device when no scheduling information is received.

[0244] In the above embodiments, the first communication device is an access point (AP), and the third communication device is any STA associated with the AP other than the second communication device. The first communication device can also send target channel access indication information to the third communication device. The channel access type indicated by the target channel access indication information for the third communication device may be the same as or different from the channel access type of the second communication device. That is, the AP can indicate the same channel access type to different STAs, or it can indicate different channel access types.

[0245] In conjunction with the above embodiments, the AP and STA can synchronize the channel access type based on whether the OBSS / main channel busy time is greater than the busy duration threshold. This can be achieved by the AP competing for the first TXOP and sending the tiger frame, while the STA waits for AP scheduling and does not participate in the competition; or both the AP and STA participate in the competition; or NPCA STAs participate in the competition while the AP does not.

[0246] In summary, in this embodiment, the first communication device can instruct the second communication device to use a hybrid scheduling and contention approach for channel access. Based on parameters such as the busy time of the first channel, the busy duration threshold, the sum of the handover and handback delays of each STA, and the number of second communication devices switching to the second channel, the device determines whether to participate in contention for the second channel or wait for scheduling by the first communication device. If waiting for scheduling, it waits to receive scheduling information; otherwise, it participates in contention for the second channel. Therefore, when there are many STAs, it can wait for scheduling, thereby reducing the collision probability of multiple STAs and achieving efficient access for multiple STAs. When there are fewer STAs, the collision probability is low, and the contention access method is more efficient, avoiding the overhead required for scheduling; thus, efficient channel access is achieved within a limited time.

[0247] Based on all the embodiments shown in Figures 9-13 above, the following describes the DPS element, DSO element, and NPCA element, IDC element, DUI element, or DUO element involved in the embodiments of this application. It should be understood that the order of the various fields shown below is merely illustrative. Furthermore, the order of the various fields can be changed, and the fields can be split or combined. For example, a field can be split into different fields, or into different frame types, or some or all fields can be combined into one field. Some fields may appear in frames used during the capability negotiation phase or capability / operation parameter update phase, and some fields may appear during the mode operation or execution phase, such as in the control frames of the execution phase, for example, in the Initial Control Frame (ICF) and the Initial Control Response Frame (ICR).

[0248] In one possible implementation, the second communication device is a STA using NPCA mode. Since the second communication device is equivalent to the TXOP responder of at least one TXOP corresponding to the first time period, during the process of the second communication device sending a control frame or management frame containing at least one of handover indication information, channel access indication information, scheduling information, etc. to the first communication device, the fields that the NPCA element contained in the control frame or management frame may contain can be referred to in Figure 14(a). The fields that the NPCA element contained in the control frame or management frame contains include at least one of the following:

[0249] Whether NPCA is supported is used to indicate whether the second communication device supports NPCA mode.

[0250] Whether to enable NPCA is used to request / suggest enabling or disabling NPCA mode to the first communication device.

[0251] Whether to enable cross-TXOP NPCA, used to request / suggest enabling or disabling cross-TXOP NPCA mode to the first communication device.

[0252] Whether to enable SP-based NPCA, used to request / suggest enabling or disabling SP-based NPCA mode to the first communication device.

[0253] Supported bandwidth and working bandwidth, including one or more of the following: working bandwidth, current bandwidth, and total bandwidth that can be supported.

[0254] The handover delay field is used to report the handover delay to the first communication device. The handover delay is the delay required to switch from the main channel to the NPCA non-main channel.

[0255] The handover delay field is used to report the handover delay to the first communication device. The handover delay is the delay required to switch from the NPCA non-primary channel to the primary channel.

[0256] The preferred channel number is used to indicate to the first communication device the number of preferred channels supported. The number of preferred channels supported is related to the reserved hardware resources.

[0257] Preferred channel information is used to indicate to the first communication device the specific preferred channel supported.

[0258] Whether preferred channel reconfiguration is supported is used to indicate to the first communication device whether the second communication device supports preferred channel reconfiguration.

[0259] The preferred channel configuration delay and preferred channel effective time recommendations are used to report the delay required for preferred channel reconfiguration to the first communication device, as well as the recommended effective time after preferred channel configuration.

[0260] The switching indication field is used to indicate the switching indication information in the foregoing embodiments.

[0261] The threshold field is used to indicate the duration threshold, etc., involved in the foregoing embodiments.

[0262] The channel switching condition field is used to indicate the parameters such as T_comm and / or T_0 in the aforementioned embodiments that meet the channel switching conditions.

[0263] The channel access indication field is used to indicate the channel access indication information in the aforementioned embodiments. The channel access indication information may include a channel busy duration threshold.

[0264] The channel access suggestion field is used to indicate the channel access suggestion information in the aforementioned embodiments.

[0265] The scheduling field is used to indicate the scheduling information in the aforementioned embodiments.

[0266] It is worth mentioning that the fields contained in the aforementioned NPCA element can be included in the same frame of interaction between the first communication device and the second communication device, or they can be included in different frames of interaction between the first communication device and the second communication device. The fields contained in the same frame can be arbitrarily combined or split. In addition, among the multiple fields mentioned in the embodiments of this application, some fields can contain multiple subfields. The multiple subfields of a field can be located in different frames or in the same frame; the aforementioned multiple fields can also be combined into a very long field.

[0267] It should be understood that the order of the multiple fields mentioned in the embodiments of this application is only an exemplary illustration, and the index (or the order of the fields) corresponding to each field can be adjusted adaptively during the application process.

[0268] Accordingly, since the first communication device is equivalent to the TXOP holder of at least one TXOP corresponding to the first time period, during the process of the first communication device sending a control frame or management frame containing at least one of handover indication information, channel access indication information, scheduling information, etc. to the second communication device, the fields that the NPCA element contained in the control frame or management frame may contain can be referred to in Figure 14(b). The fields that the NPCA element contained in the control frame or management frame contains include at least one of the following:

[0269] Whether NPCA is supported is used to indicate whether the first communication device supports NPCA mode.

[0270] Whether NPCA is enabled is used to indicate whether the second communication device has enabled NPCA mode.

[0271] Whether cross-TXOP NPCA is enabled is used to indicate whether the second communication device has enabled cross-TXOP NPCA mode.

[0272] Whether SP-based NPCA is enabled is used to indicate whether the second communication device has enabled SP-based NPCA mode.

[0273] A second communication device identifier that supports NPCA is used to indicate one or more second communication devices that support the NPCA mode.

[0274] A second communication device identifier for participating in the NPCA, used to indicate one or more second communication devices participating in the NPCA.

[0275] Whether to update the preferred channel is used to instruct some or all of the second communication devices to update the preferred channel. For example, if represented by 1 bit, setting it to 1 can indicate that the preferred channel needs to be updated. Alternatively, in addition to the 1-bit indicator bit, it may also include identification information of the specific second communication device that needs to be updated.

[0276] Preferred channel information is used to indicate a specific preferred channel to the second communication device.

[0277] The preferred channel activation time field is used to indicate the configured preferred channel activation time to the second communication device.

[0278] The threshold field is used to indicate the duration threshold, etc., involved in the foregoing embodiments.

[0279] The channel switching condition field is used to indicate the parameters such as T_comm and / or T_0 in the aforementioned embodiments that meet the channel switching conditions.

[0280] The channel access indication field is used to indicate the channel access indication information in the aforementioned embodiments.

[0281] The channel access suggestion field is used to indicate the channel access suggestion information in the aforementioned embodiments.

[0282] The scheduling field is used to indicate the scheduling information in the aforementioned embodiments.

[0283] Similarly, the fields contained in the aforementioned NPCA element can be included in the same frame of interaction between the first communication device and the second communication device, or they can be included in different frames of interaction between the first communication device and the second communication device. The fields contained in the same frame can be arbitrarily combined or split.

[0284] Similarly, the fields contained in the aforementioned NPCA element can be included in the same frame of interaction between the first communication device and the second communication device, or they can be included in different frames of interaction between the first communication device and the second communication device. The fields contained in the same frame can be arbitrarily combined or split.

[0285] In one possible implementation, the second communication device is a STA using DPS mode. During the communication interaction between the second communication device and the first communication device, when the second communication device sends a control frame or management frame containing DPS elements to the first communication device, the fields included in the DPS elements of the control frame or management frame can be referred to in Figure 15(a). Correspondingly, the fields included in the DPS elements of the control frame or management frame sent by the first communication device to the second communication device can be referred to in Figure 14(b).

[0286] The meanings of the fields in Figure 15(a) are similar to those of the corresponding fields in Figure 14(a), and can be referred to the relevant descriptions in the foregoing embodiments, which will not be repeated here. The fields with different meanings from those in Figure 14(a) are as follows:

[0287] Whether DPS is supported is used to indicate whether the second communication device supports DPS mode.

[0288] Whether to enable DPS is used to request / suggest enabling or disabling DPS mode to the first communication device.

[0289] Whether to enable cross-TXOP DPS, used to request / suggest enabling or disabling cross-TXOP DPS mode to the first communication device.

[0290] Whether to enable SP-based DPS, used to request / suggest enabling or disabling SP-based DPS mode to the first communication device.

[0291] Supported bandwidth and working bandwidth, including one or more of the following: working bandwidth, current bandwidth, and total bandwidth that can be supported.

[0292] The handover delay field is used to report the handover delay to the first communication device. The handover delay is the delay required to switch from the main channel to the NPCA sub-channel.

[0293] The handover delay field is used to report the handover delay to the first communication device. The handover delay is the delay required to switch from the NPCA main channel to the main channel.

[0294] Preferred bandwidth number, used to indicate to the first communication device the number of preferred bandwidths supported, the number of preferred bandwidths supported is related to the reserved hardware resources.

[0295] Preferred bandwidth information is used to indicate to the first communication device the specific preferred bandwidth supported.

[0296] Whether preferred bandwidth reconfiguration is supported is used to indicate to the first communication device whether the second communication device supports preferred bandwidth reconfiguration.

[0297] The preferred bandwidth configuration delay and preferred bandwidth effective time recommendations are used to report the delay required for preferred bandwidth reconfiguration to the first communication device, and to recommend the effective time after preferred bandwidth configuration.

[0298] Similarly, the fields contained in the aforementioned DPS element can be included in the same frame of interaction between the first communication device and the second communication device, or they can be included in different frames of interaction between the first communication device and the second communication device. The fields contained in the same frame can be arbitrarily combined or split.

[0299] Similarly, the meanings of the fields in Figure 15(b) can be referenced from the meanings of the corresponding fields in Figure 14(b), and will not be repeated here. The fields with different meanings from those in Figure 14(b) are as follows:

[0300] Whether DPS is supported is used to indicate whether the first communication device supports DPS mode.

[0301] Whether DPS is enabled is used to indicate whether the second communication device has enabled DPS mode.

[0302] Whether cross-TXOP DPS is enabled is used to indicate whether the second communication device enables cross-TXOP DPS mode.

[0303] Whether SP-based DPS is enabled is used to indicate whether the second communication device has enabled SP-based DPS mode.

[0304] A second communication device identifier that supports DPS, used to indicate one or more second communication devices that support DPS mode.

[0305] A second communication device identifier participating in DPS, used to indicate one or more second communication devices participating in DPS.

[0306] The handover delay field is used to report the handover delay to the first communication device. The handover delay is the delay required to switch from low capability mode to high capability mode.

[0307] The switchback delay field is used to report the switchback delay to the first communication device. The switchback delay is the delay required to switch from high capability mode to low capability mode.

[0308] Whether to update the preferred bandwidth is used to instruct some or all of the second communication devices to update the preferred bandwidth. For example, if represented by 1 bit, it can be set to 1 to indicate that the preferred bandwidth needs to be updated. Or, in addition to the 1-bit indicator bit, it also includes identification information of the specific second communication device that needs to be updated.

[0309] Preferred bandwidth information is used to indicate the specific preferred bandwidth to the second communication device.

[0310] The preferred bandwidth effective time field is used to indicate the configured preferred bandwidth effective time to the second communication device.

[0311] Similarly, the fields contained in the aforementioned DPS element can be included in the same frame of interaction between the first communication device and the second communication device, or they can be included in different frames of interaction between the first communication device and the second communication device. The fields contained in the same frame can be arbitrarily combined or split.

[0312] In one possible implementation, the second communication device is a STA applying DSO mode. During the communication interaction between the second communication device and the first communication device, when the second communication device sends a control frame or management frame containing DSO elements to the first communication device, the fields included in the DSO elements of the control frame or management frame can be referred to in Figure 16(a). Correspondingly, the fields included in the DSO elements of the control frame or management frame sent by the first communication device to the second communication device can be referred to in Figure 14(b).

[0313] The meanings of the fields in Figure 16(a) are similar to those of the corresponding fields in Figure 14(a), and can be referred to the relevant descriptions in the foregoing embodiments, which will not be repeated here. The fields with different meanings from those in Figure 14(a) are as follows:

[0314] Whether DSO is supported is used to indicate whether the second communication device supports DSO mode.

[0315] Whether to enable DSO is used to request / suggest enabling or disabling DSO mode to the first communication device.

[0316] Whether to enable cross-TXOP DSO is used to request / suggest enabling or disabling cross-TXOP DSO mode to the first communication device.

[0317] Whether to enable SP-based DSO, used to request / suggest enabling or disabling SP-based DSO mode to the first communication device.

[0318] The preferred channel number is used to indicate to the first communication device the number of preferred channels supported. The number of preferred channels supported is related to the reserved hardware resources.

[0319] Preferred channel information is used to indicate to the first communication device the specific preferred channel supported.

[0320] Whether preferred channel reconfiguration is supported is used to indicate to the first communication device whether the second communication device supports preferred channel reconfiguration.

[0321] The preferred channel configuration delay and preferred channel effective time recommendations are used to report the delay required for preferred channel reconfiguration to the first communication device, as well as the recommended effective time after preferred channel configuration.

[0322] Similarly, the fields contained in the aforementioned DSO element can be included in the same frame of interaction between the first communication device and the second communication device, or they can be included in different frames of interaction between the first communication device and the second communication device. The fields contained in the same frame can be arbitrarily combined or split.

[0323] Similarly, the meanings of the fields in Figure 16(b) can be referenced from the meanings of the corresponding fields in Figure 14(b), and will not be repeated here. The fields with different meanings from those in Figure 16(b) are as follows:

[0324] Whether DSO is supported is used to indicate whether the first communication device supports DSO mode.

[0325] Whether DSO is enabled is used to indicate whether the second communication device has enabled DSO mode.

[0326] Whether DSO across TXOP is enabled is used to indicate whether the second communication device enables DSO mode across TXOP.

[0327] Whether SP-based DSO is enabled is used to indicate whether the second communication device has enabled SP-based DSO mode.

[0328] A second communication device identifier that supports DSO, used to indicate one or more second communication devices that support DSO mode.

[0329] A second communication device identifier participating in the DSO, used to indicate one or more second communication devices participating in the DSO.

[0330] The handover delay field is used to report the handover delay to the first communication device. The handover delay is the delay required to switch from the DSO main channel to the DSO sub-channel.

[0331] The switchback delay field is used to report the switchback delay to the first communication device. The switchback delay is the delay required to switch from the DSO sub-channel to the DSO main channel.

[0332] Whether to update the preferred channel is used to instruct some or all of the second communication devices to update the preferred channel. For example, if represented by 1 bit, setting it to 1 can indicate that the preferred channel needs to be updated. Alternatively, in addition to the 1-bit indicator bit, it may also include identification information of the specific second communication device that needs to be updated.

[0333] Preferred channel information is used to indicate a specific preferred channel to the second communication device.

[0334] The preferred channel activation time field is used to indicate the configured preferred channel activation time to the second communication device.

[0335] The fields contained in the aforementioned DSO element can be included in the same frame of interaction between the first communication device and the second communication device, or they can be included in different frames of interaction between the first communication device and the second communication device. The fields contained in the same frame can be arbitrarily combined or split.

[0336] In one possible implementation, the second communication device is a STA applying IDC, DUI, or DUO mode. During the communication interaction between the second communication device and the first communication device, the second communication device sends a control frame or management frame containing IDC, DUI, or DUO elements to the first communication device. The fields included in the IDC, DUI, or DUO elements in the control frame or management frame can be referred to in Figure 14(a). Correspondingly, the fields included in the IDC, DUI, or DUO elements in the control frame or management frame sent by the first communication device to the second communication device can be referred to in Figure 14(b).

[0337] The meanings of the fields in Figure 17(a) are similar to those of the corresponding fields in Figure 14(a), and can be referred to the relevant descriptions in the foregoing embodiments, which will not be repeated here. The fields with different meanings from those in Figure 14(a) are as follows:

[0338] Whether IDC, DUI, or DUO is supported is used to indicate whether the second communication device supports IDC, DUI, or DUO mode.

[0339] Whether to enable IDC, DUI, or DUO is used to request / suggest enabling or disabling IDC, DUI, or DUO mode to the first communication device.

[0340] Whether to enable or disable cross-TXOP IDC, DUI, or DUO mode, used to request / suggest enabling or disabling cross-TXOP IDC, DUI, or DUO mode to the first communication device.

[0341] Whether to enable SP-based IDC, DUI, or DUO is used to request / suggest enabling or disabling SP-based IDC, DUI, or DUO mode to the first communication device.

[0342] The interference duration field is used to report the duration of interference to the first communication device.

[0343] The handover delay field is used to report the handover delay to the first communication device. The handover delay is the delay required to switch from the main channel to the sub-channel or non-main channel.

[0344] The switchback delay field is used to report the switchback delay to the first communication device. The switchback delay is the delay required to switch from a sub-channel or non-primary channel to the primary channel.

[0345] Similarly, the fields contained in the aforementioned IDC, DUI, or DUO elements can be included in the same frame of interaction between the first and second communication devices, or in different frames of interaction between the first and second communication devices. The fields contained in the same frame can be arbitrarily combined or split.

[0346] Similarly, the meanings of the fields in Figure 17(b) can be referenced from the meanings of the corresponding fields in Figure 14(b), and will not be repeated here. The fields with different meanings from those in Figure 14(b) are as follows:

[0347] Whether IDC, DUI, or DUO is supported is used to indicate whether the first communication device supports IDC, DUI, or DUO mode.

[0348] Whether IDC, DUI, or DUO is enabled is used to indicate whether the second communication device has enabled IDC, DUI, or DUO mode.

[0349] Whether IDC, DUI, or DUO is enabled across TXOP is used to indicate whether the second communication device enables IDC, DUI, or DUO mode across TXOP.

[0350] Whether SP-based IDC, DUI, or DUO is enabled is used to indicate whether the second communication device has enabled SP-based IDC, DUI, or DUO mode.

[0351] A second communication device identifier that supports IDC, DUI, or DUO, used to indicate one or more second communication devices that support IDC, DUI, or DUO modes.

[0352] A second communication device identifier that participates in IDC, DUI, or DUO, used to indicate one or more second communication devices participating in IDC, DUI, or DUO.

[0353] The fields contained in the aforementioned IDC, DUI, or DUO elements can be included in the same frame of interaction between the first communication device and the second communication device, or they can be included in different frames of interaction between the first communication device and the second communication device. The fields contained in the same frame can be arbitrarily combined or split.

[0354] The communication method provided by the embodiments of this application has been described in detail above with reference to Figures 9-17. The communication apparatus used to perform the communication method provided by the embodiments of this application is described in detail below with reference to Figures 18 and 19.

[0355] For example, FIG18 is a schematic diagram of the structure of a communication device provided in an embodiment of this application. As shown in FIG18, the communication device 1800 includes a transceiver module 1801 and a processing module 1802. For ease of explanation, FIG18 only shows the main components of the communication device.

[0356] In some embodiments, the communication device 1800 may be adapted to the communication system shown in FIG8 to perform the functions of the terminal device in the communication methods shown in FIG9-FIG17.

[0357] Processing module 1802 is used to acquire a first moment; the first moment is the end time of the busy time of the first channel, or the first moment is before the end time; before the first moment, the first communication device communicates on the second channel;

[0358] The transceiver module 1801 is used to initiate a switch from the second channel to the first channel at the first moment; wherein the first communication device switches back to the first channel before the duration of the loss of medium synchronization on the first channel reaches the medium synchronization threshold (aMediumSyncThershold).

[0359] Alternatively, the transceiver module 1801 is used to acquire channel access indication information;

[0360] Processing module 1802 is configured to, if the channel access indication information indicates that the channel access type of the second communication device is a mixture of scheduling and contention, synchronize the current access type of the second channel with the first communication device according to the busy time of the first channel and the channel access indication information, wherein the current access type includes waiting for the first communication device to schedule or participating in contention for the second channel; the first channel is a channel through which the first communication device and the second communication device can communicate outside the busy time; and access the second channel using the current access type.

[0361] The specific implementation described above can be found in the relevant descriptions of the methods provided in Figures 9-17, and will not be repeated here. Optionally, the transceiver module 1801 may include a receiving module and a transmitting module (not shown in Figure 18). The transceiver module is used to implement the transmitting and receiving functions of the communication device 1800.

[0362] Optionally, the communication device 1800 may further include a storage module that stores programs or instructions. When the transceiver module 1801 executes the program or instructions, the communication device 1800 can perform the functions of the terminal device in the communication method shown in Figures 9-17.

[0363] It should be understood that the transceiver module 1801 can be implemented by a transceiver or transceiver-related circuit components, and can be a transceiver or transceiver unit.

[0364] Furthermore, the communication device 1800 can be a terminal, a chip (system), or other components or parts, or a device containing a terminal; this application does not limit this. The aforementioned chip (system) or other components or parts can all be located in a terminal or network device. The technical effects of the communication device 1800 can be seen in the technical effects of the communication method shown in Figures 9-17, and will not be repeated here.

[0365] In other embodiments, the communication device 1800 may be adapted to the communication system shown in FIG8 to perform the functions of the network device in the communication methods shown in FIG9-FIG17.

[0366] Processing module 1802 is used to acquire a first moment; the first moment is the end time of the busy time of the first channel, or the first moment is before the end time; before the first moment, the first communication device communicates on the second channel.

[0367] The transceiver module 1801 is used to initiate a switch from the second channel to the first channel at the first moment; wherein the first communication device switches back to the first channel before the duration of the loss of medium synchronization on the first channel reaches the medium synchronization threshold (aMediumSyncThershold).

[0368] Alternatively, the transceiver module 1801 is used to acquire channel access indication information.

[0369] Processing module 1802 is configured to, if the channel access indication information indicates that the channel access type of the second communication device is a mixture of scheduling and contention, synchronize the current access type of the second channel with the first communication device according to the busy time of the first channel and the channel access indication information, wherein the current access type includes waiting for the first communication device to schedule or participating in contention for the second channel; the first channel is a channel through which the first communication device and the second communication device can communicate outside the busy time; and access the second channel using the current access type.

[0370] Optionally, the communication device 1800 may further include a storage module that stores programs or instructions. When the transceiver module 1801 executes the program or instructions, the communication device 1800 can perform the functions of the network device in the communication method shown in Figures 9-17.

[0371] It should be understood that the transceiver module 1801 can be implemented by a transceiver or transceiver-related circuit components, and can be a transceiver or transceiver unit.

[0372] Furthermore, the communication device 1800 may be a network device, a chip (system) or other component or assembly disposed in the aforementioned network device, or a device containing the network device; this application embodiment does not limit this. The technical effects of the communication device 1800 can be referred to the technical effects of the communication methods shown in Figures 9-17, and will not be repeated here.

[0373] For example, Figure 19 is a second schematic diagram of the structure of a communication device provided in an embodiment of this application. This communication device can be a terminal device or a network device, or it can be a chip (system) or other component or assembly that can be disposed in a terminal device or network device. As shown in Figure 19, the communication device 1900 may include a processor 1901. Optionally, the communication device 1900 may also include a memory 1902 and / or a transceiver 1903. The processor 1901 is coupled to the memory 1902 and the transceiver 1903, for example, they can be connected via a communication bus.

[0374] The following is a detailed description of the various components of the communication device 1900, with reference to Figure 19:

[0375] The processor 1901 is the control center of the communication device 1900. It can be a single processor or a collective term for multiple processing elements. For example, the processor 1901 can be one or more central processing units (CPUs), application-specific integrated circuits (ASICs), or one or more integrated circuits configured to implement the embodiments of this application, such as one or more digital signal processors (DSPs), or one or more field-programmable gate arrays (FPGAs).

[0376] Optionally, the processor 1901 can perform various functions of the communication device 1900 by running or executing software programs stored in the memory 1902 and calling data stored in the memory 1902.

[0377] In a specific implementation, as one example, processor 1901 may include one or more CPUs, such as CPU0 and CPU1 shown in FIG19.

[0378] In a specific implementation, as one embodiment, the communication device 1900 may also include multiple processors, such as processors 1901 and 1904 shown in FIG. 19. Each of these processors may be a single-core processor (single-CPU) or a multi-core processor (multi-CPU). Here, a processor may refer to one or more devices, circuits, and / or processing cores for processing data (e.g., computer program instructions).

[0379] The memory 1902 is used to store the software program that executes the solution of this application, and is controlled by the processor 1901 to execute it. The specific implementation method can be referred to the above method embodiment, and will not be repeated here.

[0380] Optionally, the memory 1902 may be a read-only memory (ROM) or other type of static storage device capable of storing static information and instructions, random access memory (RAM) or other type of dynamic storage device capable of storing information and instructions, or electrically erasable programmable read-only memory (EEPROM), compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compressed optical discs, laser discs, optical discs, digital universal optical discs, Blu-ray discs, etc.), magnetic disk storage media or other magnetic storage devices, or any other medium capable of carrying or storing desired program code in the form of instructions or data structures and accessible by a computer, but not limited thereto. The memory 1902 may be integrated with the processor 1901 or may exist independently and be coupled to the processor 1901 through the interface circuit of the communication device 1900 (not shown in FIG. 19). This embodiment of the application does not specifically limit this.

[0381] Transceiver 1903 is used for communication with other communication devices. For example, if communication device 1900 is a terminal device, transceiver 1903 can be used to communicate with a network device or with another terminal device. As another example, if communication device 1900 is a network device, transceiver 1903 can be used to communicate with a terminal device or with another network device.

[0382] Optionally, transceiver 1903 may include a receiver and a transmitter (not shown separately in Figure 19). The receiver is used to implement the receiving function, and the transmitter is used to implement the transmitting function.

[0383] Optionally, the transceiver 1903 can be integrated with the processor 1901 or exist independently and be coupled to the processor 1901 through the interface circuit of the communication device 1900 (not shown in FIG19). This application embodiment does not specifically limit this.

[0384] It should be noted that the structure of the communication device 1900 shown in Figure 19 does not constitute a limitation on the communication device. The actual communication device may include more or fewer components than shown, or combine certain components, or have different component arrangements.

[0385] Furthermore, the technical effects of the communication device 1900 can be referred to the technical effects of the communication method described in the above method embodiments, and will not be repeated here.

[0386] It should be understood that the processor in the embodiments of this application can be a CPU, but it can also be other general-purpose processors, DSPs, ASICs, FPGAs, or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or any conventional processor, etc.

[0387] It should also be understood that the memory in the embodiments of this application can be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. Non-volatile memory can be ROM, programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), EEPROM, or flash memory. Volatile memory can be RAM, which is used as an external cache. By way of example, but not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous linked dynamic random access memory (SLDRAM), and direct rambus RAM (DR RAM).

[0388] The above embodiments can be implemented, in whole or in part, by software, hardware (such as circuits), firmware, or any other combination thereof. When implemented using software, the above embodiments can be implemented, in whole or in part, in the form of a computer program product. The computer program product includes one or more computer instructions or computer programs. When the computer instructions or computer programs are loaded or executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more sets of available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium. A semiconductor medium can be a solid-state drive.

[0389] It should be understood that the term "and / or" in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. A and B can be singular or plural. Additionally, the character " / " in this article generally indicates an "or" relationship between the preceding and following related objects, but it can also represent an "and / or" relationship. Please refer to the context for a more accurate understanding.

[0390] In this application, "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, at least one of a, b, or c can mean: a, b, c, ab, ac, bc, or abc, where a, b, and c can be single or multiple.

[0391] It should be understood that in the various embodiments of this application, the order of the above-mentioned processes does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0392] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0393] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0394] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0395] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0396] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0397] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, ROM, RAM, magnetic disks, or optical disks.

[0398] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A communication method, characterized in that, Applied to a first communication device, the method includes: The first moment is obtained; the first moment is the end time of the busy time of the first channel, or the first moment is before the end time; before the first moment, the first communication device communicates on the second channel; At the first moment, a switch from the second channel to the first channel is initiated; wherein, the first communication device switches back to the first channel before the duration of the loss of media synchronization on the first channel reaches the media synchronization threshold (aMediumSyncThershold).

2. The communication method according to claim 1, characterized in that, The first time point is determined based on the target time point; The target time is determined based on at least one of the following: the busy time of the first channel, the switchback delay of the first communication device, the switchback delay of the second communication device, and aMediumSyncThershold; the first communication device and the second communication device communicate with each other through the first channel and / or the second channel.

3. The communication method according to claim 2, characterized in that, The first time is the target time; or the first time is before the target time, and the duration between the first time and the target time is less than the duration required to complete one frame interaction in the second channel.

4. The communication method according to claim 2, characterized in that, The target time is the time corresponding to the target duration that is earlier than the end time of the busy time of the first channel; The target duration is the switchback delay of the first communication device, or the difference between the switchback delay of the second communication device and the aMediumSyncThershold.

5. The communication method according to claim 4, characterized in that, If the switchback delay of the first communication device is greater than or equal to the difference between the switchback delay of the second communication device and the aMediumSyncThershold, then the target duration is the switchback delay of the first communication device; If the handover delay of the first communication device is less than the difference between the handover delay of the second communication device and the aMediumSyncThershold, then the target duration is the difference between the handover delay of the second communication device and the aMediumSyncThershold; the first communication device is a wireless access point (AP), the second communication device is some or all of the STAs associated with the AP, and the handover delay of the second communication device is the maximum, minimum, or average value of the handover delays of all or some of the devices in the second communication device.

6. The communication method according to claim 1, characterized in that, The first moment is the moment when the duration of the first communication device stopping frame interaction in the second channel reaches the duration threshold.

7. The communication method according to claim 1, characterized in that, The method further includes: Send a handover indication message to at least one of the second communication devices. The handover indication message is used to instruct the second communication device to initiate a handover from the second channel to the first channel at a second time. The handover indication message is carried in a downlink frame sent during the capability negotiation phase or update phase of the target mode. The target mode is any one of the following: NPCA mode, DPS mode, DSO mode, IDC or DUI or DUO mode.

8. The communication method according to claim 7, characterized in that, The second time is the first time; or, the second time is the first time delayed by a preset duration; or, the second time is the time corresponding to the switchback delay of the second communication device that is earlier than the end time of the busy time of the first channel.

9. The communication method according to any one of claims 1-8, characterized in that, The method further includes: When the conditions for channel switching are met, the system switches from the first channel to the second channel; The conditions for satisfying the channel switching include: the duration of the first communication device's stay on the second channel is greater than or equal to the duration required for the first communication device to access the second channel and perform frame interaction on the second channel; or, the busy duration of the first channel is greater than or equal to a duration threshold, wherein, within the busy duration range of the first channel, the first communication device can complete the switching from the first channel to the second channel, and access the second channel and perform frame interaction on the second channel.

10. The communication method according to claim 9, characterized in that, The dwell time is the difference between the busy duration of the first channel and the switching delay of the first communication device; Alternatively, the dwell time is the difference between the busy duration and the sum of the switching delay and the switchback delay of the first communication device; Alternatively, the dwell time is the difference between the busy duration and the sum of the switching delay of the first communication device and the switching-back delay of the second communication device; Alternatively, the dwell time is the difference between the sum of the busy duration and the aMediumSyncThershold and the switching delay of the first communication device; Alternatively, the dwell time is the difference between the sum of the busy duration and the aMediumSyncThershold and the sum of the switching delay of the first communication device and the switching-back delay of the second communication device.

11. The communication method according to claim 10, characterized in that, The first communication device is an AP, and the second communication device is some or all of the STAs associated with the AP; The handover delay of the second communication device is the maximum, minimum, or average value of the handover delay of all or some STAs in the second communication device.

12. The communication method according to claim 9, characterized in that, The first communication device is an AP, and the second communication device is some or all of the STAs associated with the AP; The duration threshold is greater than or equal to the sum of the maximum latency and the duration required to access the second channel and perform frame interaction on the second channel; The maximum delay is the maximum sum of the switching delay and the switchback delay in the first communication device and the second communication device, or the maximum switching delay in the first communication device and the second communication device, or the maximum switchback delay in the first communication device and the second communication device.

13. The communication method according to claim 9, characterized in that, The conditions for not satisfying the channel switching include at least one of the following: the sum of the switching delay and the switchback delay in the second communication device is greater than or equal to the difference between the duration threshold and the duration required to access the second channel and perform frame interaction in the second channel; or the switching delay or switchback delay in the second communication device is greater than or equal to the difference between the duration threshold and the duration required to access the second channel and perform frame interaction in the second channel.

14. The communication method according to claim 9, characterized in that, The first communication device is an AP, and the second communication device is some or all of the STAs associated with the AP; The conditions for satisfying the channel switching also include: at least one second communication device satisfies that the dwell time on the second channel is greater than or equal to the time required for the second communication device to access the second channel and perform frame interaction on the second channel, or at least one second communication device satisfies that the busy duration of the first channel is greater than or equal to the duration threshold, wherein, within the busy duration range of the first channel, the second communication device can complete the switching from the first channel to the second channel, and access the second channel and perform frame interaction on the second channel.

15. The communication method according to claim 9, characterized in that, The busy duration of the first channel is from the moment when the first communication device decides to start switching from the first channel to the second channel to the end of the busy time of the first channel.

16. The communication method according to claim 9, characterized in that, The first communication device is an AP, and the second communication device is some or all of the STAs associated with the AP; The time required to complete access to the second channel and perform frame interaction on the second channel is determined by at least one of the following: uplink communication, downlink communication, and channel access type. The channel access type may include any of the following: contention, scheduling, scheduling by the AP only in the first TXOP, downlink transmission by the AP or sending downlink frames by the AP, contention by the AP only in the first TXOP, the AP sending the first frame, and a combination of contention and scheduling.

17. The communication method according to claim 9, characterized in that, Information used to indicate the time required to complete access to the second channel and perform frame interaction on the second channel is carried in the uplink or downlink frames negotiated and sent during the capability negotiation phase or update phase of the target mode; wherein, the target mode is any one of the following: NPCA mode, DPS mode, DSO mode, IDC or DUI or DUO mode.

18. The communication method according to claim 17, characterized in that, The uplink frame is at least one of the following: association request frame, or reassociation request frame, target mode enable frame, target mode notification frame, or target mode dedicated management frame; The downlink frame is at least one of the following: a beacon frame, a data transmission indication information, a beacon frame or a transmission indication mapping frame, or a target mode dedicated management frame.

19. A communication method applied to a second communication device, characterized in that, The method includes: Obtain channel access indication information; If the channel access indication information indicates that the channel access type of the second communication device is a mixture of scheduling and contention, then based on the busy time of the first channel and the channel access indication information, the current access type of the second channel is synchronized with the first communication device. The current access type includes waiting for the first communication device to schedule or participating in contention for the second channel. The first channel is a channel through which the first communication device and the second communication device can communicate outside of the busy time. Access the second channel using the current access type.

20. The communication method according to claim 19, characterized in that, The channel access indication information also includes a busy duration threshold; When the busy time of the first channel is greater than or equal to the busy duration threshold, and / or the number of second communication devices switching to the second channel exceeds the number threshold, the current access type is waiting for the first communication device to schedule; the number of second communication devices switching to the second channel is determined based on the busy time of the first channel, the busy duration threshold, or the switching delay and switchback delay of the second communication device; When the busy time of the first channel is less than the busy duration threshold, and / or the number of second communication devices switching to the second channel does not exceed the number threshold, the current access type is to compete for the second channel.

21. The communication method according to claim 19, characterized in that, If the current access type is waiting for the first communication device to schedule; The step of accessing the second channel using the current access type includes: receiving scheduling information sent by the first communication device.

22. The communication method according to claim 19, characterized in that, The first communication device is an access point (AP), and the second communication device is a STA associated with the AP. The acquisition of channel access indication information includes: Receive channel access indication information sent by the first communication device; The channel access indication information can indicate that the channel access type of the second communication device is any of the following: waiting for scheduling, only scheduled by the AP in the first TXOP, the AP transmits downlink or the AP sends downlink frames, only the first TXOP is limited to contention by the AP, the AP sends the first frame, participation in contention and the type of contention, mixed scheduling and contention, and scheduling priority.

23. The communication method according to claim 19, characterized in that, The first communication device is an access point (AP), and the second communication device is all or some of the STAs associated with the AP; the method further includes: Send channel access suggestion information to the first communication device. The channel access suggestion information can suggest that the channel access type of the second communication device is any of the following: scheduling, scheduling by the AP only in the first TXOP, downlink transmission by the AP or sending downlink frames by the AP, contention by the AP only in the first TXOP, sending the first frame by the AP, participation in contention and the type of contention, mixed scheduling and contention, scheduling priority; The acquisition of channel access indication information includes: Receive channel access indication information returned by the first communication device based on the access indication suggestion information.

24. The communication method according to claim 22 or 23, characterized in that, The channel access indication information is carried in the downlink frame during the capability negotiation or update phase of the target mode, and the channel access indication suggestion information is carried in the uplink frame during the capability negotiation or update phase of the target mode; the target mode is any one of the following: NPCA mode, DPS mode, DSO mode, IDC or DUI or DUO mode.

25. The communication method according to claim 24, characterized in that, The uplink frame is at least one of the following: association request frame, or reassociation request frame, target mode enable frame, target mode notification frame, or target mode dedicated management frame; The downlink frame is at least one of the following: a beacon frame, a data transmission indication information, a beacon frame or a transmission indication mapping frame, or a target mode dedicated management frame.

26. The communication method according to claim 19, characterized in that, The process of obtaining the channel access indication information further includes: if the channel access indication information indicates that the channel access type of the second communication device is scheduling priority... Waiting for the scheduling information to be sent by the first communication device; If the waiting time exceeds the waiting threshold, then the system will begin competing for the second channel.

27. A communication method applied to a first communication device, characterized in that, The method includes: Send channel access indication information; If the channel access indication information indicates that the channel access type of the second communication device is a mixture of scheduling and contention, then based on the busy time of the first channel and the channel access indication information, the current access type of the second channel is synchronized with the second communication device. The current access type includes waiting for the first communication device to schedule or participating in contention for the second channel. The first channel is a channel through which the first communication device and the second communication device can communicate outside of the busy time. If the current access type is waiting for the first communication device to schedule, send scheduling information to the second communication device.

28. A communication device, characterized in that, The communication device is used to perform the method as described in any one of claims 1-26.

29. A computer program product, characterized in that, The computer program product includes: a computer program or instructions that, when run on a computer, cause the computer to perform the method as described in any one of claims 1-26.

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