Channel access method and related apparatus for multi-link devices

Abstract

This invention provides a channel access method and related apparatus for a non-STR (Simultaneous Transmit / Receive) MLD (Multi-Link Device) that improves channel access efficiency when the MLD is in a blind / self-interfering state. [Solution] A method applicable to a wireless local area network supporting the IEEE 802.11be standard, comprising the step that if the length of a first PPDU transmitted by the first MLD over a first link is less than or equal to a first value, the first MLD skips starting the medium synchronization delay timer with respect to the second link, and the first MLD is not permitted to perform simultaneous transmission and reception on the first and second links. Channel access efficiency can be improved when a non-STR MLD is in a blind / self-interfering state.

Description

Technical Field

[0001]

[0001] This application claims priority to Chinese Patent Application No. 202010924423.8, filed with the China National Intellectual Property Administration on September 4, 2020, entitled "Channel Access Method and Related Device for Multi-Link Device", the entire content of which is incorporated herein by reference.

[0002]

[0002] Technical Field This application relates to the field of wireless communication technologies, particularly to channel access methods and related devices for multi-link devices.

Background Art

[0003]

[0003] As wireless communication technologies develop, a growing number of wireless communication devices support multi-link communication, such as simultaneously communicating in frequency bands of 2.4 GHz, 5 GHz, and 6 GHz, or simultaneously communicating in different channels of the same frequency band. This type of wireless communication device is usually referred to as a multi-link device (MLD). Obviously, a multi-link device can perform parallel communication using multiple links, thereby significantly improving the transmission rate.

[0004]

[0004] Multi-link devices can perform parallel communication by using multiple links to increase the transmission rate, but if the frequency spacing between the multiple frequency bands supported by an extremely high throughput (EHT) multi-link device is small, signal transmission in one frequency band affects signal reception in another frequency band. For example, if an EHT multi-link device performs transmission on link 1, and the frequency spacing between link 1 and link 2 is small, signal transmission in link 1 causes channel interference to link 2, affecting channel access and information reception in link 2. Therefore, to avoid mutual interference, devices are not permitted to independently perform simultaneous transmission and reception in multiple frequency bands. According to the current progress of the 802.11 TGbe standardization group, EHT multi-link devices may have simultaneous transmitting and receiving (STR) capability and non-simultaneous transmitting and receiving (non-STR) capability.

[0005]

[0005] When an MLD with non-STR capability (referred to as a non-STR MLD) transmits on a link, the non-STR MLD is in a blind state (referred to as a blind period or hearing loss period) because it interferes with clear channel assessment (CCA) performed on another link. Being blind means that no information on the channel can be heard, or fails to hear any information on the channel. Therefore, if a non-STR MLD is blind on some links, how the non-STR MLD performs channel access on those links becomes an urgent issue to be resolved. [Overview of the project]

[0006]

[0006] Embodiments of the present invention provide a channel access method and related apparatus for multi-link devices that improve channel access efficiency when a non-STR MLD is in a blind / self-interfering state.

[0007]

[0007] The present invention will be described below from various aspects. It should be understood that cross-referencing may be made to the various embodiments and beneficial effects described below.

[0008]

[0008] According to a first aspect, the present invention provides a channel access method for a multilink device. The method is as follows: If the length of a first PPDU transmitted by the first multilink device over a first link is less than or equal to a first value, the first multilink device does not start a medium synchronization delay timer with respect to the second link. The first multilink device is not permitted to perform simultaneous transmission and reception with respect to the first and second links.

[0009]

[0009] The first multi-link device not starting a media synchronization delay timer with respect to the second link includes: when channel contention is performed with respect to the second link, the first link device sets the energy detection threshold used by the clear channel evaluation CCA performed with respect to the second link to a first threshold, where the first threshold is -62 dBm; or, after the back-off counter has backed off to 0 with respect to the second link, the first multi-link device is allowed to transmit frames other than RTS frames and MU-RTS frames.

[0010]

[0010] In this solution, if the length of the PPDU transmitted on one link is below a certain value, the media synchronization delay timer is not started for the other link; or, if channel contention occurs on the other link, the energy detection threshold used in the CCA is set to -62 dBm; or, it is not necessary to use the RTS frame on the other link to attempt to detect channel protection / availability. Thus, the channel access efficiency or channel access success rate of the first multi-link device on the other link is improved, or the channel access opportunities of the first multi-link device on the other link are increased.

[0011]

[0011] With respect to the first aspect, in a possible implementation, the method further includes: a first multi-link device receiving a first value. The first value may be carried in a beacon frame, an association response frame, or a reassociation response frame.

[0012]

[0012] Optionally, the first value may be carried by a multi-link element, an ultra-high throughput operation element, or a newly defined element.

[0013]

[0013] With respect to the first embodiment, in a possible implementation, the method further includes: if the length of the first PPDU is greater than a first value, the first multi-link device determines an initial value for the media synchronization delay timer which corresponds to the length of the first PPDU, and starts the media synchronization delay timer with respect to the second link using that initial value.

[0014]

[0014] Optionally, the method further includes: a first multi-link device receiving first instruction information. The first instruction information is used to indicate a mapping relationship between the length of a physical layer protocol data unit (PPDU) and the initial value of a media synchronization delay timer.

[0015]

[0015] In this solution, the initial value of the media synchronization delay timer is determined based on the length of the first PPDU, allowing for more flexible configuration of the media synchronization delay timer.

[0016]

[0016] With respect to the first embodiment, in a possible implementation, the method further includes: the step of the first multi-link device starting a second synchronous delay timer with respect to the second link if the length of the first PPDU is greater than a first value; and the step of the first multi-link device setting an energy sensing threshold used by a CCA performed with respect to the second link to a threshold corresponding to the length of the first PPDU, if the first multi-link device is performing channel contention with respect to the second link during the period in which the media synchronous delay timer is operating.

[0017]

[0017] Optionally, before the first multi-link device transmits the first PPDU over the first link, the method further includes: the first multi-link device receiving second instruction information. The second instruction information is used to specify a mapping relationship between the length of the PPDU and the energy detection threshold.

[0018]

[0018] In this solution, the energy detection threshold is determined based on the length of the first PPDU. In this case, the channel access mechanism used in the second link is more flexible and improves channel access efficiency.

[0019]

[0019] According to a second aspect, the present invention provides a first multi-link device or a chip within the first multi-link device, for example, a Wi-Fi chip. The first multi-link device may be a non-STR MLD. The first multi-link device includes a processing unit. The processing unit is configured to skip starting a media synchronization delay timer with respect to the second link if the length of a first PPDU transmitted over the first link by the first multi-link device is less than or equal to a first value. The first multi-link device is not permitted to perform simultaneous transmission and reception with respect to the first and second links.

[0020]

[0020] The processing unit is configured to set the energy detection threshold used by the Clear Channel Assessment (CCA) performed on the second link to a first threshold, where the first threshold is -62 dBm. Alternatively, the first multi-link device further includes a transceiver unit. The transceiver unit is configured to transmit frames other than RTS frames and MU-RTS frames after the back-off counter has backed off to 0 with respect to the second link.

[0021]

[0021] In a second embodiment, in a possible implementation, the first multi-link device further includes a transceiver unit. The transceiver unit is further configured to receive a first value. The first value may be carried in a beacon frame, an association response frame, or a reassociation response frame.

[0022]

[0022] Optionally, the first value may be carried by a multi-link element, an ultra-high throughput operation element, or a newly defined element.

[0023]

[0023] In a second embodiment, in a possible implementation, the processing unit is further configured to determine an initial value for the media synchronization delay timer that corresponds to the length of the first PPDU when the length of the first PPDU is greater than the first length, and to start the media synchronization delay timer with respect to the second link using that initial value.

[0024]

[0024] Optionally, the first multi-link device further includes a transceiver unit. The transceiver unit is further configured to receive first instruction information. The first instruction information is used to indicate a mapping relationship between the length of the PPDU and the initial value of the media synchronization delay timer.

[0025]

[0025] In a second embodiment, in a possible implementation, the processing unit is further configured to: start a synchronous delay timer with respect to the second link if the length of the first PPDU is greater than a first value; and, if the first multi-link device is performing channel contention with respect to the second link during the period in which the media synchronous delay timer is operating, set the energy detection threshold used by the CCA performed with respect to the second link to a threshold corresponding to the length of the first PPDU.

[0026]

[0026] Optionally, the first multi-link device further includes a transceiver unit. The transceiver unit is further configured to receive second instruction information. The second instruction information is used to specify a mapping relationship between the length of the PPDU and the energy detection threshold.

[0027]

[0027] According to the third aspect, the present application provides a channel access method for a multi-link device. The method is as follows: when the type of the first frame transmitted on the first link by the first multi-link device is the first type, the first multi-link device does not start a media synchronization delay timer for the second link. The first multi-link device is not allowed to perform simultaneous transmission and reception for the first link and the second link.

[0028]

[0028] The fact that the first multi-link device does not start a media synchronization delay timer for the second link means that: when performing channel contention for the second link, the first multi-link device sets the energy detection threshold used by the clear channel assessment CCA to the first threshold, where the first threshold is -62 dBm; or, after the back-off counter for the second link backs off to 0, the first multi-link device is allowed to transmit frames other than the RTS frame and the MU-RTS frame.

[0029]

[0029] Optionally, the first frame is the following frame: request to send (RTS) frame, multiple user request to send (MU-RTS) frame, Power save-Poll (PS-Poll) frame, clear to send CTS frame, buffer status report (BSR) frame, bandwidth query report (BQR) frame, null data packet (NDP) frame, acknowledge (ACK) frame, and Block Acquisition (block ACK, BA) Frame If any of the above conditions are met, the first frame type is the first type.

[0030]

[0030] Optionally, the first frame is a request to send (RTS) frame or a multiple user request to send (MU-RTS) frame. If the first multi-link device does not receive a clear to send (CTS) frame with respect to the first link within a predetermined period, the first multi-link device does not start the media synchronization delay timer with respect to the second link.

[0031]

[0031] Optionally, the first frame is a Power Save Polling (PS-Poll) frame. If the first multilink device does not receive a data frame or acknowledgment frame with respect to the first link within a predetermined period, the first multilink device does not start the media synchronization delay timer with respect to the second link.

[0032]

[0032] Optionally, the first frame is a CTS frame. Before the first multi-link device transmits the first PPDU on the first link, the method further includes: the first multi-link device receiving an RTS frame or an MU-RTS frame on the first link.

[0033]

[0033] Optionally, the first frame is a status report BSR frame. Before the first multi-link device transmits the first PPDU on the first link, the method further includes: the first multi-link device receiving a status report polling BSRP trigger frame on the first link.

[0034]

[0034] Optionally, the first frame is a bandwidth query report BQR frame. Before the first multi-link device transmits the first PPDU on the first link, the method further includes: the first multi-link device receiving a bandwidth query report polling BQRP trigger frame on the first link.

[0035]

[0035] Optionally, the first frame is a null data packet NDP frame. Before the first multi-link device transmits the first PPDU on the first link, the method further includes: the first multi-link device receiving a beamforming report polling BFRP trigger frame on the first link.

[0036]

[0036] Optionally, the first frame is an ACK frame or a BA frame. Before the first multi-link device transmits the first PPDU on the first link, the method further includes: the first multi-link device receiving a data frame or a management frame on the first link.

[0037]

[0037] According to a fourth aspect, the present invention provides a first multi-link device or a chip within the first multi-link device, for example, a Wi-Fi chip. The first multi-link device may be a non-STR MLD. The first multi-link device includes a processing unit. The processing unit is configured to skip starting a medium synchronization delay timer with respect to the second link if the type of the first frame transmitted over the first link by the first multi-link device is of type 1. The first multi-link device is not permitted to perform simultaneous transmission and reception with respect to the first and second links.

[0038]

[0038] The processing unit is configured to set the energy detection threshold used by the Clear Channel Assessment (CCA) performed on the second link to a first threshold, where the first threshold is -62 dBm. Alternatively, the first multi-link device further includes a transceiver unit. The transceiver unit is configured to transmit frames other than RTS frames and MU-RTS frames after the back-off counter has backed off to 0 with respect to the second link.

[0039]

[0039] Optionally, the first frame is the following frame: Request-to-Send (RTS) frame, Multi-user request-to-send (multiple user RTS, MU-RTS) frames, Power save pole (PS-Poll) frame, CTS frame, Status report (buffer status report, BSR) frame, Bandwidth query report (BQR) frame, Null data packet (NDP) frame, The acknowledge (ACK) frame, and Block Acquisition (block ACK, BA) Frame If any of the above conditions are met, the first frame type is the first type.

[0040]

[0040] Optionally, the first frame is an RTS frame or a MU-RTS frame. Specifically, the processing unit is configured to skip starting the media synchronization delay timer for the second link if it does not receive a clear to send (CTS) frame for the first link within a predetermined period.

[0041]

[0041] Optionally, the first frame is a PS-Poll frame. Specifically, the processing unit is configured to skip starting the media synchronization delay timer for the second link if it does not receive a PS-Poll frame for the first link within a predetermined period.

[0042]

[0042] Optionally, the first frame is a CTS frame. The first multi-link device further includes a transceiver unit. The transceiver unit is configured to receive RTS frames or MU-RTS frames on the first link.

[0043]

[0043] Optionally, the first PPDU is a status report BSR frame. The first multi-link device further includes a transceiver unit. The transceiver unit is configured to receive a status report polling BSRP trigger frame on the first link.

[0044]

[0044] Optionally, the first PPDU is a bandwidth query report BQR frame. The first multi-link device further includes a transceiver unit. The transceiver unit is configured to receive bandwidth query report polling BQRP trigger frames on the first link.

[0045]

[0045] Optionally, the first PPDU is a null data packet NDP frame. The first multi-link device further includes a transceiver unit. The transceiver unit is configured to receive beamforming report polling BFRP trigger frames on the first link.

[0046]

[0046] Optionally, the first frame is an ACK frame or a BA frame. The first multi-link device further includes a transceiver unit, which is configured to receive data frames or management frames on the first link.

[0047]

[0047] According to a fifth aspect, the present invention provides a method for determining the initial period of a media synchronization delay timer. The method comprises: a first multi-link device receiving first instruction information, which is used to indicate a mapping relationship between the length of a PPDU and the initial value (or initial period) of a media synchronization delay timer. The first multi-link device determines an initial value of the media synchronization delay timer, which corresponds to the length of the first PPDU, based on the length of a first PPDU transmitted on the first link, and this initial value is used to determine whether to start the media synchronization delay timer with respect to the second link. The first multi-link device is not permitted to perform simultaneous transmission and reception on the first and second links.

[0048]

[0048] Optionally, the first multi-link device determines whether to start the media sync delay timer with respect to the second link based on an initial value of the media sync delay timer, which corresponds to the length of the first PPDU.

[0049]

[0049] Optionally, if the determined initial value of the media sync delay timer is equal to 0, the first multi-link device does not start the media sync delay timer for the second link. If the determined initial value of the media sync delay timer is equal to 0, the first multi-link device starts the media sync delay timer for the second link using the initial value.

[0050]

[0050] The fact that the first multi-link device may start a mediumSyncDelay timer with respect to the second link can be understood (or stated) as: during the period in which the mediumSyncDelay timer is operating, the first multi-link device may use a more conservative channel access mechanism with respect to the second link. A more conservative channel access mechanism may include, but is not limited to, (1) using a lower energy detection threshold (here, an ED threshold lower than -62 dBm) to determine whether the channel is busy; and (2) it may be required to transmit an RTS frame in an attempt to detect the channel's availability.

[0051]

[0051] This solution allows various PPDU lengths / byte lengths to correspond to various initial values ​​of the mediumSyncDelay timer, enabling more flexible configuration of the mediumSyncDelay timer and improving channel access efficiency.

[0052]

[0052] According to a sixth aspect, the present invention provides a method for determining the initial period of a media synchronization delay timer. The method includes: a second multi-link device generating and transmitting first instruction information. The first instruction information is used to indicate a mapping relationship between the PPDU length and the initial value (or initial period) of the media synchronization delay timer.

[0053]

[0053] According to a seventh aspect, the present application provides a first multi-link device or a chip within the first multi-link device, for example, a Wi-Fi chip. The first multi-link device may be a non-STR MLD. The communication device includes: a transceiver unit configured to receive first instruction information, the first instruction information being used to indicate a mapping relationship between PPDU length and the initial value of a media synchronization delay timer; and a processing unit configured to determine an initial value of a media synchronization delay timer corresponding to the length of the first PPDU based on the length of a first PPDU transmitted over the first link. The communication device is not permitted to transmit and receive simultaneously on the first and second links.

[0054]

[0054] Optionally, the processing unit is further configured to determine whether to start the media synchronization delay timer for the second link based on an initial value of the media synchronization delay timer, which corresponds to the length of the first PPDU.

[0055]

[0055] Optionally, the processing unit is configured to: skip starting the media synchronization delay timer for the second link if the determined initial value of the media synchronization delay timer is equal to 0; or start the media synchronization delay timer for the second link if the determined initial value of the media synchronization delay timer is equal to 0.

[0056]

[0056] According to an eighth aspect, the present application provides a second multi-link device or a chip within a second multi-link device, for example, a Wi-Fi chip. The second multi-link device may be an STR MLD. The communication device includes: a processing unit configured to generate first instruction information, the first instruction information being used to indicate a mapping relationship between PPDU length and initial value (or initial period) of a media synchronization delay timer; and a transceiver unit configured to transmit the first instruction information.

[0057]

[0057] According to a ninth aspect, the present invention provides a method for determining an energy detection threshold in a CCA process. The method comprises: a first multi-link device receiving second instruction information, the second instruction information being used to indicate a mapping relationship between PPDU length and an energy detection threshold. The first multi-link device transmits a first PPDU on a first link. Based on the length of the first PPDU transmitted on the first link, the first multi-link device determines an energy detection threshold corresponding to the length of the first PPDU, where the energy detection threshold is used to determine whether to start a medium synchronization delay timer with respect to the second link. The first multi-link device is not permitted to transmit and receive simultaneously on the first and second links.

[0058]

[0058] Optionally, the first multi-link device determines whether to start a medium synchronization delay timer for the second link based on an energy detection threshold corresponding to the length of the first PPDU.

[0059]

[0059] Optionally, if the determined energy detection threshold is equal to -62 dBm, the first multi-link device does not start the medium synchronization delay timer for the second link; or, if the determined energy detection threshold is less than -62 dBm, the first multi-link device starts the medium synchronization delay timer for the second link.

[0060]

[0060] In this solution, different PPDU lengths / byte lengths correspond to different energy detection thresholds. In this case, the channel access mechanism used in the second link is more flexible and improves channel access efficiency.

[0061]

[0061] According to a tenth aspect, the present invention provides a method for determining an energy detection threshold in a CCA process. The method includes: a second multi-link device generating and transmitting second instruction information. The second instruction information is used to indicate a mapping relationship between the PPDU length and the energy detection threshold.

[0062]

[0062] According to an eleventh aspect, the present application provides a first multi-link device or a chip within the first multi-link device, for example, a Wi-Fi chip. The first multi-link device may be a non-STR MLD. The communication device includes: a transceiver unit configured to receive a second instruction information, the second instruction information being used to indicate a mapping relationship between PPDU length and an energy detection threshold; and a processing unit configured to determine an energy detection threshold corresponding to the length of a first PPDU based on the length of a first PPDU transmitted over the first link, the energy detection threshold being used to determine whether to start a medium synchronization delay timer with respect to the second link. The first multi-link device is not permitted to perform simultaneous transmission and reception on the first and second links.

[0063]

[0063] Optionally, the processing unit is further configured to determine whether to start a medium synchronization delay timer for the second link based on an energy detection threshold corresponding to the length of the first PPDU. The communication device is not permitted to transmit and receive simultaneously on the first and second links.

[0064]

[0064] Optionally, the processing unit is configured to: skip starting the media synchronization delay timer for the second link if the determined energy detection threshold is equal to -62 dBm; or start the media synchronization delay timer for the second link if the determined energy detection threshold is less than -62 dBm.

[0065]

[0065] According to a twelfth aspect, the present application provides a second multi-link device or a chip within a second multi-link device, for example, a Wi-Fi chip. The second multi-link device may be an STR MLD. The communication device includes: a processing unit configured to generate second instruction information, the second instruction information being used to indicate a mapping relationship between PPDU length and an energy detection threshold; and a transceiver unit configured to transmit the second instruction information.

[0066]

[0066] According to a thirteenth aspect, the present invention provides a first multi-link device including a processor. Optionally, a transceiver is further included. The processor is configured to skip starting a medium synchronization delay timer for the second link if the length of a first PPDU transmitted over the first link by the first multi-link device is less than or equal to a first value. The first multi-link device is not permitted to perform simultaneous transmission and reception on the first and second links.

[0067]

[0067] In a possible design, the processor is configured to skip starting the medium synchronization delay timer with respect to the second link if the type of the first frame transmitted on the first link by the first multi-link device is of type 1. The first multi-link device is not permitted to perform simultaneous transmission and reception on the first and second links.

[0068]

[0068] In a possible design, the transceiver is configured to receive first instruction information, which is used to specify a mapping relationship between the PPDU length and the initial value (or initial period) of the media synchronization delay timer; and the processor is configured to determine an initial value of the media synchronization delay timer, which corresponds to the length of the first PPDU, based on the length of the first PPDU transmitted over the first link. The communication device is not permitted to perform simultaneous transmission and reception on the first and second links.

[0069]

[0069] In a possible design, the transceiver is configured to receive a second instruction information, which is used to indicate a mapping relationship between PPDU length / byte length and an energy detection threshold; and to determine an energy detection threshold corresponding to the length of a first PPDU based on the length of a first PPDU transmitted on the first link, which is used to determine whether to start a medium synchronization delay timer with respect to the second link. The first multi-link device is not permitted to transmit and receive simultaneously on the first and second links.

[0070]

[0070] According to a fourteenth aspect, the present invention provides a second multi-link device comprising a processor and a transceiver. The processor is configured to generate first instruction information, which is used to indicate a mapping relationship between the PPDU length and the initial value (or initial period) of the media synchronization delay timer. The transceiver is configured to transmit the first instruction information.

[0071]

[0071] In a possible design, the processor is configured to generate a second instruction information which is used to indicate a mapping relationship between the PPDU length and the energy detection threshold; and the transceiver is configured to transmit the second instruction information.

[0072]

[0072] According to a 15th aspect, the present application provides a first multi-link device. The first multi-link device may exist in the form of a chip. The structure of the first multi-link device includes an input / output interface and processing circuitry. The input / output interface is configured to receive code instructions and transmit the code instructions to the processing circuitry. The processing circuitry is configured to skip starting a medium synchronization delay timer with respect to the second link if the length of the first PPDU is less than or equal to a first value. The first multi-link device is not permitted to perform simultaneous transmission and reception with respect to the first and second links.

[0073]

[0073] In a possible design, the input / output interface is configured to receive a code instruction and transmit the code instruction to a processing circuit. The processing circuit is configured to skip starting the medium synchronization delay timer with respect to the second link if the type of the first frame transmitted over the first link by the first multi-link device is of type 1. The first multi-link device is not permitted to perform simultaneous transmission and reception on the first and second links.

[0074]

[0074] In a possible design, the transceiver is configured to receive first instruction information, and the input / output interface is configured to receive the first instruction information from the transceiver, transmit the first instruction information to a processing circuit for processing, and obtain a mapping relationship between the PPDU length and the initial value (or initial period) of the media synchronous delay timer; and the processing circuit is configured to determine an initial value of the media synchronous delay timer, which corresponds to the length of the first PPDU, based on the length of the first PPDU transmitted over the first link. The initial value is used to determine whether to start the media synchronous delay timer with respect to the second link. The first multi-link device is not permitted to perform simultaneous transmission and reception on the first and second links.

[0075]

[0075] In a possible design, the transceiver is configured to receive a second instruction information, and the input / output interface is configured to receive the second instruction information from the transceiver, transmit the second instruction information to a processing circuit for processing, and obtain a mapping relationship between PPDU length / byte length and energy detection threshold indicated by the second instruction information; and the processing circuit is configured to determine an energy detection threshold corresponding to the length of the first PPDU based on the length of the first PPDU transmitted on the first link. The energy detection threshold is used to determine whether to start a medium synchronization delay timer with respect to the second link. The first multi-link device is not permitted to transmit and receive simultaneously on the first and second links.

[0076]

[0076] According to a sixteenth aspect, the present application provides a second multi-link device. The second multi-link device may exist in the form of a chip. The structure of the second multi-link device includes an input / output interface and a processing circuit. The input / output interface is configured to receive code instructions and transmit the code instructions to the processing circuit. The processing circuit is configured to generate first instruction information, which is used to indicate a mapping relationship between the PPDU length and the initial value (or initial period) of the medium synchronization delay timer. The input / output interface is configured to transmit the first instruction information to a transceiver. The transceiver is configured to transmit the first instruction information.

[0077]

[0077] In a possible implementation, the input / output interface is configured to receive a code instruction and transmit the code instruction to a processing circuit; the processing circuit is configured to generate a second instruction information, which is used to indicate a mapping relationship between the PPDU length and the energy detection threshold; the input / output interface is configured to transmit the second instruction information to a transceiver; and the transceiver is configured to transmit the second instruction information.

[0078]

[0078] According to the 17th aspect, the present invention provides a computer-readable storage medium. The computer-readable storage medium stores instructions, and when the instructions are executed by a computer, the computer can perform a method according to the first, third, fifth, seventh, ninth, or tenth aspect.

[0079]

[0079] According to the 18th aspect, the present application provides a computer program product including program instructions. When the program instructions are executed by a computer, the computer is able to perform a method according to the first, third, fifth, seventh, ninth, or tenth aspect.

[0080]

[0080] When an embodiment of the present invention is implemented, channel access efficiency can be improved when a non-STR MLD is in a blind / self-interfering state. [Brief explanation of the drawing]

[0081]

[0081] In order to more clearly explain the technical solution in the embodiment of this invention, the attached drawings illustrating the embodiment will be briefly described below. [Figure 1]

[0082] Figure 1 is a schematic diagram of communication between a non-AP MLD and an AP MLD according to an embodiment of the present invention. [Figure 2]

[0083] Figure 2 is a schematic diagram of the architecture of a wireless communication system according to an embodiment of the present invention. [Figure 3a]

[0084] Figure 3a is a schematic diagram of the structure of a multi-link device according to an embodiment of the present invention. [Figure 3b]

[0085] Figure 3b is a schematic diagram of another structure of the multi-link device according to an embodiment of the present invention. [Figure 4]

[0086] Figure 4 is a schematic flowchart of a channel access method for a multi-link device according to an embodiment of the present invention. [Figure 5]

[0087] Figure 5 is another schematic flowchart of a channel access method for a multi-link device according to an embodiment of the present invention. [Figure 6a]

[0088] Figure 6a is a schematic diagram of the frame structure of a multi-link element according to an embodiment of the present invention. [Figure 6b]

[0089] Figure 6b is a schematic diagram of the frame structure of an EHT operation element according to an embodiment of the present invention. [Figure 6c]

[0090] Figure 6c is a schematic diagram of the frame structure of a non-STR MLD parameter set element according to an embodiment of the present invention. [Figure 7]

[0091] Figure 7 is a schematic flowchart of the method for determining the initial period of the media synchronization delay timer according to the embodiment of the present invention. [Figure 8]

[0092] Figure 8 is a schematic diagram of the mapping relationship between the PPDU length and the initial value of the media synchronization delay timer according to the embodiment of the present invention. [Figure 9]

[0093] Figure 9 is a schematic flowchart of the method for determining the energy detection threshold in the CCA process according to an embodiment of the present invention. [Figure 10]

[0094] Figure 10 is a schematic diagram of the mapping relationship between PPDU length and energy detection threshold according to an embodiment of the present invention. [Figure 11]

[0095] Figure 11 is a schematic diagram of the structure of a first multi-link device according to an embodiment of the present invention. [Figure 12]

[0096] Figure 12 is a schematic diagram of the structure of a second multi-link device according to an embodiment of the present invention. [Modes for carrying out the invention]

[0082]

[0097] The technical solutions in the embodiments of this application will be clearly and fully described below with reference to the accompanying drawings of the embodiments.

[0083]

[0098] To facilitate understanding of the channel access method for multilink devices provided in the embodiments of this application, the system architecture and / or application scenarios of the channel access method for multilink devices provided in the embodiments of this application are described below. It will be understood that the system architecture and / or scenarios described in the embodiments of this application are intended to more clearly describe the technical solution in the embodiments of this application and do not constitute a limitation of the technical solution provided in the embodiments of this application.

[0084]

[0099] Embodiments of the present invention provide a channel access method applicable to non-STR MLDs. By using this method, channel access efficiency can be improved when the non-STR MLD is in a blind / self-interfering state. The channel access method for multi-link devices can be implemented by a communication device in a wireless communication system, or by a chip or processor in the communication device. The communication device may be a wireless communication device that supports parallel transmission performed on multiple links. For example, the communication device may be referred to as a multi-link device or a multi-band device. Compared to a communication device that supports only single-link transmission, a multi-link device has higher transmission efficiency and higher throughput.

[0085]

[0100] A multi-link device includes one or more affiliated stations (STAs). An affiliated station is a logical station and operates on a link, frequency band, or channel. An affiliated station may be an access point (AP) or a non-access point station (non-AP STA). For convenience of explanation, in this application, a multi-link device whose affiliated station is an AP is referred to as a multi-link AP, a multi-link AP device, or an AP multi-link device (AP MLD), and a multi-link device whose affiliated station is a non-AP STA is referred to as a multi-link non-AP, a multi-link non-AP device, or a non-AP multi-link device (non-AP MLD).

[0086]

[0101] Optionally, a single multi-link device may contain multiple logical stations, each operating on a single link, but multiple logical stations are allowed to operate on the same link.

[0087]

[0102] Optionally, one or more STAs in a non-AP MLD may establish association relationships with one or more APs in an AP MLD and then perform communication. Figure 1 is a schematic diagram of communication between a non-AP MLD and an AP MLD according to an embodiment of the present invention. As shown in Figure 1, the AP MLD includes AP1, AP2, ..., APn, and the non-AP MLD includes STA1, STA2, ..., STAn. The AP MLD and the non-AP MLD can communicate in parallel using links 1, 2, ..., n. STA1 of the non-AP MLD establishes an association relationship with AP1 of the AP MLD; STA2 of the non-AP MLD establishes an association relationship with AP2 of the AP MLD; STA3 of the non-AP MLD establishes an association relationship with AP3 of the AP MLD; and so on.

[0088]

[0103] Optionally, multi-link devices may comply with IEEE 802.11 series protocols to conduct wireless communication. For example, a station compliant with extremely high throughput (EHT), or a station compliant with or capable of supporting IEEE 802.11 be, will communicate with other devices.

[0089]

[0104] The channel access method for multi-link devices provided in the embodiments of the present application may be applied to a scenario in which one node communicates with one or more nodes, or to a single-user uplink / downlink communication scenario or a multi-user uplink / downlink communication scenario, or to a device-to-device (D2D) communication scenario.

[0090]

[0105] Any one of the aforementioned nodes may be an AP MLD or a non-AP MLD, for example, in a scenario where an AP MLD communicates with a non-AP MLD, an AP MLD communicates with another AP MLD, or a non-AP MLD communicates with another non-AP MLD. This is not limited to the embodiments of the present invention.

[0091]

[0106] Optionally, in any of the aforementioned scenarios, there is at least one node that is not permitted to perform simultaneous transmission and reception, i.e., has non-STR capability.

[0092]

[0107] Optionally, for the sake of simplicity, the system architecture of the present invention will be described below by using a scenario in which an AP MLD communicates with a non-AP MLD as an example. The channel access method for multilink devices provided in embodiments of the present invention may be applied to a wireless local area network (WLAN). Figure 2 is a schematic diagram of the architecture of a wireless communication system according to embodiments of the present invention. As shown in Figure 2, the wireless communication system includes at least one AP MLD and at least one non-AP MLD. The AP MLD is a multilink device that provides services to the non-AP MLD. The non-AP MLD can communicate with the AP MLD using multiple links. One AP in the AP MLD can communicate with one STA in the non-AP MLD using one link. It will be understood that the number of AP MLDs and non-AP MLDs in Figure 2 are for illustrative purposes only. Optionally, the wireless communication system includes at least one MLD having non-STR capability.

[0093]

[0108] For example, a multi-link device (here, either a non-AP MLD or an AP MLD) is a device equipped with wireless communication capabilities. The device may be an integrated device, or it may be a chip or processing system mounted on an integrated device. A device equipped with a chip or processing system can implement the methods and functions provided in embodiments of the present application under the control of the chip or processing system. For example, a non-AP multi-link device in embodiments of the present application may have wireless transceiver functionality, support the 802.11 series protocol, and may communicate with an AP multi-link device or another non-AP multi-link device. For example, a non-AP multi-link device is any user communication device that enables a user to communicate with an AP and then with a WLAN. For example, a non-AP multi-link device may be a user device capable of connecting to a network, such as a tablet computer, desktop computer, laptop computer, notebook computer, ultra-mobile personal computer (UMPC), handheld computer, netbook, personal digital assistant (PDA), or mobile phone; or it may be an Internet of Things node in the Internet of Things; or it may be an in-vehicle communication device in the Internet of Vehicles. Alternatively, a non-AP multi-link device may be a chip and processing system in the above-mentioned terminal. An AP multi-link device may be a device that provides services to a non-AP multi-link device and may support 802.11 series protocols. For example, an AP multi-link device may be a communication entity such as a communication server, router, switch, or network bridge; or it may include various forms of macro base stations, micro base stations, relay stations, etc.Indeed, an AP multi-link device may be a chip or processing system in these various forms of devices. The 802.11 protocol may be a protocol that supports 802.11 be, or one that is compatible with 802.11 be.

[0094]

[0109] It can be understood that multi-link devices have the potential to support high-speed, low-latency transmission. With the continuous advancements in wireless local area network application scenarios, multi-link devices can be applied to a wider range of scenarios, such as sensor nodes in smart cities (e.g., smart meters, smart electric meters, smart air sensing nodes), smart devices in smart homes (e.g., smart cameras, projectors, displays, televisions, stereos, refrigerators, washing machines), Internet of Things nodes, entertainment terminals (e.g., wearable devices such as AR and VR), smart devices in smart offices (e.g., printers and projectors), IoV devices for the Internet of Vehicles, and some infrastructure in everyday life scenarios (e.g., vending machines, self-service navigation stations in supermarkets, self-service cash register devices, self-service ordering machines). Specific forms of multi-link devices are not limited to this embodiment of the present application, and are merely examples provided here.

[0095]

[0110] Optionally, Figure 3a is a schematic diagram of the structure of a multi-link device according to an embodiment of the present invention. The IEEE 802.11 standard focuses on the 802.11 physical layer (PHY) and the 802.11 medium access control (MAC) layer in a multi-link device. As shown in Figure 3a, the multiple STAs included in the multi-link device are independent of each other in the low MAC layer and PHY layer, and also independent of each other in the high MAC layer. Figure 3b is a schematic diagram of another structure of a multi-link device according to an embodiment of the present invention. As shown in Figure 3b, the multiple STAs included in the multi-link device are independent of each other in the low MAC layer and PHY layer, and share a high MAC layer. Of course, non-AP multi-link devices may use a structure in which the high MAC layer is independent of each other, or a structure in which the high MAC layer is shared. Similarly, the AP multi-link device may use a structure in which the high MAC layers are shared, or it may use a structure in which the high MAC layers are independent of each other. Schematic diagrams of the internal structure of the multi-link device are not limited to the embodiments of this application. Figures 3a and 3b are merely illustrative examples. For example, the high MAC layers or low MAC layers may be implemented by one processor in the chip system of the multi-link device, or by different processing modules in the chip system.

[0096]

[0111] For example, the multi-link device in the embodiments of the present application may be a single-antenna device or a multi-antenna device, such as a device having two or more antennas. The number of antennas included in the multi-link device is not limited in the embodiments of the present application. In the embodiments of the present application, the multi-link device may allow services of the same access category (AC) to be transmitted over different links, and may even allow the same data packets to be transmitted over different links; or alternatively, it may not allow services of the same access category to be transmitted over different links, but may allow services of different access categories to be transmitted over different links.

[0097]

[0112] The frequency bands in which multi-link devices operate may include one or more of the following frequency bands: sub-1 GHz, 2.4 GHz, 5 GHz, 6 GHz, and high frequency 60 GHz.

[0098]

[0113] In the case of a non-STR MLD, when a non-STR MLD transmits on a link (e.g., link 1), channel interference can cause the non-STR MLD to incorrectly determine the channel status on another link or multiple links (for example, link 2 is used), affecting the non-STR MLD's reception of overlapped basic service set (OBSS) frames on link 2. OBSS frames are used by stations to update the network allocation vector (NAV). Therefore, before a transmission performed on a link is completed, the non-STR MLD may miss OBSS frames on another link and subsequently miss NAV updates. In this case, if the non-STR MLD experiences channel contention on link 2 and accesses the channel after a transmission performed on link 1 has completed, the data transmitted on link 2 will collide with the received OBSS frames. This is known as the blind problem or self-interference problem.

[0099]

[0114] NAV can be understood as a countdown timer, gradually decreasing over time. When NAV is 0, the medium is considered idle. Specifically, after a station receives a frame, if the receiving address of the frame is not that station, the station may update its NAV based on the duration field of the received frame. If the receiving address of the frame is that station, it indicates that the station is the receiving station. In this case, the station is not permitted to update its NAV. Before updating its NAV, the station may further determine whether the value of the duration field of the current frame is greater than the station's current NAV value. If the value of the duration field of the current frame is greater than the station's current NAV value, the station updates its NAV. If the value of the duration field of the current frame is less than or equal to the station's current NAV value, the station does not update its NAV. The NAV value that exists at the time the frame reception ends is used for comparison.

[0100]

[0115] To address the blindness problem in non-STR MLDs, embodiments of the present invention propose a medium sync delay (mediumSyncDelay) mechanism. Specifically, this mechanism is as follows: After performing a transmission on a link (e.g., link 1), the non-STR MLD is required to start a timer for another link, namely a mediumSyncDelay timer. During the period indicated by the mediumSyncDelay timer, the non-STR MLD is required to use a more conservative channel access mechanism for link 2. A more conservative channel access mechanism includes, but is not limited to, the following: (1) Whether a channel is busy is determined by using an energy detection (ED) threshold. In channel access mechanisms, -62 dBm is typically used as the energy detection threshold. If the energy in a channel is detected to be above the threshold, i.e., above -62 dBm, the channel is considered busy. If an ED threshold lower than -62 dBm is used, a more distant signal will make the channel busy in CCA detection. Therefore, channel access is more conservative. The low-energy detection threshold may be -82 dBm, -72 dBm, etc. (2) In order to attempt to detect channel availability, a request-to-send (RTS) frame must be transmitted. Optionally, this may be a one-time attempt (or a one-time transmission of an RTS frame) or a limited number of attempts.

[0101]

[0116] In the media synchronization delay mechanism, as long as the non-STR MLD transmits on Link 1, the non-STR MLD uses a more conservative channel access mechanism with respect to Link 2, regardless of the type of frame transmitted by the non-STR MLD on Link 1. However, the frames transmitted by the non-STR MLD on Link 1 can be of various types, including control frames, data frames, or management frames, and data frames may be long or short frames. Therefore, if the non-STR MLD transmits short frames on Link 1, the non-STR MLD will be blinded on Link 2 for a short period of time, and the likelihood (or probability) of the non-STR MLD missing important information about Link 2 (e.g., NAV) is low. In conclusion, the media synchronization delay mechanism requires that as long as the non-STR MLD transmits on Link 1, channel access of the non-STR MLD on Link 2 is restricted. This results in low channel access efficiency, a low channel access success rate, and reduced channel access opportunities on Link 2.

[0102]

[0117] In this application, "a non-STR MLD is blind in the link" may be interpreted alternatively as "an STA in a non-STR MLD that operates in that link is blind."

[0103]

[0118] It should be understood that the "blind state" referred to in this application may also be called a "self-interference state," a "state of inability to receive," or a "state of being unable to hear."

[0104]

[0119] It should be understood that the term "non-STR MLD" in this application may also refer to an EHT MLD that is not permitted to perform simultaneous transmission and reception.

[0105]

[0120] It will be understood that the terms "long frame" and "short frame" as used in this application are distinguished from each other by the length of time the frame occupies the air interface. For example, a "long frame" may be a frame that occupies the air interface for a duration greater than or equal to a predetermined value A, while a "short frame" may be a frame that occupies the air interface for a duration less than or equal to a predetermined value B. The predetermined values ​​A and B may be the same or different. For example, the predetermined value A may be 1 ms (millisecond), and the predetermined value B may be 100 μs (microseconds).

[0106]

[0121] Embodiments of the present invention provide a channel access method for multi-link devices that improves the channel access efficiency or channel access success rate of non-STR MLDs on some links, or increases the channel access opportunities of non-STR MLDs on links when they are in a blind / self-interfering state on those links.

[0107]

[0122] The technical solutions provided in this application will be described in detail below with reference to the attached drawings.

[0108]

[0123] In this application, it will be understood that the first multi-link device may be a non-STR MLD, and the second multi-link device may be an STR MLD. For the sake of facilitating the following explanation, a scenario in which two MLDs communicate via two or more links is used as an example in the explanation of this application. In the following embodiments, two links are used as an example to illustrate the technical solution of this application. However, the technical solution of this application is also applicable to two MLDs supporting multiple links.

[0109]

[0124] The technical solutions provided herein are described in detail using Embodiments 1 to 4. Embodiment 1 describes in detail how channel access is performed on one link when a particular type of frame is transmitted on another link. Embodiment 2 describes in detail how it is determined whether a more conservative channel access mechanism needs to be used on another link based on the length of the frame transmitted on one link. Embodiment 3 describes in detail how the initial period of the mediumSyncDelay timer is determined. Embodiment 4 describes in detail how the ED threshold used in the CCA process is determined.

[0110]

[0125] Embodiments 1 to 4 will be described in detail below. It will be understood that the technical solutions described in Embodiments 1 to 4 of this application may be arbitrarily combined to form new embodiments.

[0111]

[0126] Embodiment 1 Embodiment 1 of the present invention describes a method for determining whether it is necessary to use a more conservative channel access mechanism on another link based on the type of frame transmitted on one link.

[0112]

[0127] Figure 4 is a schematic flowchart of a channel access method for a multi-link device according to an embodiment of the present invention. As shown in Figure 4, the channel access method for a multi-link device includes, but is not limited to, the following steps.

[0113]

[0128] S101: If the type of the first frame transmitted over the first link by the first multi-link device is of type 1, the first multi-link device does not start the medium synchronization delay timer with respect to the second link, where the first multi-link device is not permitted to perform simultaneous transmission and reception with respect to the first and second links.

[0114]

[0129] The type of the first frame is the first type if the first frame is one of the following frames: request to send (RTS) frame, multiple user request to send (MU-RTS) frame, power save-poll (PS-Poll) frame, clear to send (CTS) frame, buffer status report (BSR) frame, bandwidth query report (BQR) frame, null data packet (NDP) frame, acknowledge (ACK) frame, or block acknowledge (BA) frame.

[0115]

[0130] In the first implementation, the first frame is an RTS frame or an MU-RTS frame. Specifically, if the first multi-link device transmits an RTS frame or an MU-RTS frame on the first link but does not receive a clear-to-send frame within a predetermined period, the first multi-link device does not start a medium sync delay timer for the second link. The first multi-link device is not permitted to transmit or receive simultaneously on both the first and second links. In other words, if the first multi-link device does not receive a CTS frame on the first link within a predetermined period (e.g., the sum of the length of the short inter-frame space (SIFS), the length of one slot, and the physical layer receive delay, i.e., SIFS Time + Slot Time + RxPHYStartDelay) after transmitting an RTS / MU-RTS frame on the first link, the first multi-link device will not start the mediumSyncDelay timer for the second link.

[0116]

[0131] The fact that the first multi-link device does not start the mediumSyncDelay timer with respect to the second link may be understood (or stated) as follows: If the first multi-link device performs channel contention on the second link, the energy detection threshold used by the CCA operation is the first threshold; or, after the back-off counter for the second link has backed off to 0, the first multi-link device is permitted to immediately transmit frames other than RTS and MU-RTS frames. In other words, after the back-off counter for the second link has backed off to 0, the first multi-link device does not transmit RTS / MU-RTS frames in an attempt to detect channel protection / availability. The first threshold may be -62 dBm.

[0117]

[0132] The reasons why the first multi-link device does not receive a CTS frame within a predetermined period (e.g., SIFS Time + Slot Time + RxPHYStartDelay) could be: (a) an RTS frame transmitted by the first multi-link device is in conflict with a frame transmitted by another device; (b) the receiver corresponding to the RTS frame transmitted by the first multi-link device fails to successfully receive the RTS frame; and (c) the receiver corresponding to the RTS frame transmitted by the first multi-link device is busy.

[0118]

[0133] Optionally, after the first multi-link device transmits an RTS / MU-RTS frame on the first link, it starts a mediumSyncDelay timer for the second link. If the first multi-link device does not receive a CTS frame within a predetermined period, the first multi-link device closes (or stops or cancels) the mediumSyncDelay timer.

[0119]

[0134] Optionally, if the first multi-link device receives a CTS frame within a predetermined period, the first multi-link device may initiate a mediumSyncDelay timer. The initiation of the mediumSyncDelay timer with respect to the second link by the first multi-link device may be understood (or stated) as follows: The first multi-link device uses a more conservative channel access mechanism with respect to the second link. Specifically, a low energy detection threshold (this is an energy detection threshold lower than -62 dBm, e.g., -82 dBm) is used to determine if the channel is busy, and an RTS / MU-RTS frame is transmitted to attempt to detect channel availability. Optionally, this may be a one-time attempt (or a one-time transmission of an RTS / MU-RTS frame) or a limited number of attempts.

[0120]

[0135] Optionally, the “RTS frame or MU-RTS frame” in the first implementation may be replaced with a Power save-Poll (PS-Poll) frame, and the “CTS frame” in the first implementation may be replaced with a data frame or an acknowledgment (ACK) frame. Thus, the first implementation may be alternatively stated as follows: If the first multi-link device transmits a PS-Poll frame on the first link but does not receive a data frame or acknowledgment frame within a predetermined period, the first multi-link device does not start the medium sync delay timer for the second link. Optionally, if the first multi-link device transmits a PS-Poll frame on the first link and receives a data frame or acknowledgment frame within a predetermined period, the first multi-link device may start the mediumSyncDelay timer.

[0121]

[0136] If a non-STR MLD (i.e., the first multi-link device) of this embodiment of the present application transmits an RTS (or MU-RTS) frame on the first link but does not receive a CTS frame, the non-STR MLD does not start the mediumSyncDelay timer with respect to the second link. As a result, the non-STR MLD can know that it is performing common channel contention with respect to the second link, i.e., that the energy detection threshold used in CCA operations is -62 dBm, or that the RTS / CTS frame may not be used to attempt to detect channel protection. Thus, the channel access efficiency or channel access success rate of the non-STR MLD with respect to the second link is improved, or the channel access opportunities of the non-STR MLD with respect to the second link are increased.

[0122]

[0137] In the second implementation, the first frame is a CTS frame. Specifically, if the first multi-link device receives an RTS frame or MU-RTS frame on the first link and responds using a CTS frame on the first link, the first multi-link device does not start the medium sync delay timer on the second link. The first multi-link device is not permitted to transmit or receive simultaneously on the first and second links. In other words, the second multi-link device transmits an RTS frame or MU-RTS frame on the first link. Correspondingly, the first multi-link device receives an RTS frame or MU-RTS frame on the first link and responds using a CTS frame on the first link, transmitting a CTS frame. After transmitting a CTS frame on the first link, the first multi-link device does not start the medium sync delay timer on the second link.

[0123]

[0138] The fact that the first multi-link device does not start the mediumSyncDelay timer with respect to the second link may be understood (or stated) as follows: when the first multi-link device performs channel contention on the second link, the energy sensing threshold used by the CCA operation is the first threshold; or, after the back-off counter for the second link has backed off to 0, the first multi-link device is permitted to immediately transmit frames other than RTS and MU-RTS frames. In other words, after the back-off counter for the second link has backed off to 0, the first multi-link device does not transmit RTS / MU-RTS frames in an attempt to detect channel protection / availability. The first threshold may be -62 dBm.

[0124]

[0139] Optionally, if the first multi-link device has transmitted a CTS frame on the first link and has started the mediumSyncDelay timer for the second link, the first multi-link device closes (or stops or cancels) the mediumSyncDelay timer.

[0125]

[0144] Optionally, in the second implementation, the "RTS / CTS frame" may be replaced with a buffer status report poll trigger (BSRP Trigger) frame / buffer status report (BSR) frame, a bandwidth query report poll trigger (BQRP Trigger) frame / bandwidth query report (BQR) frame, a beamforming report poll trigger (BFRP Trigger) frame / null data packet (NDP) frame, a data frame / acknowledgment (ACK) frame, a management frame / ACK frame, or a data frame / block acknowledge (BA) frame. Therefore, step S201 may alternatively be described as follows: the first multi-link device receives a BSRP trigger frame on the first link and responds using a BSR frame on the first link / transmits a BSR frame; or the first multi-link device receives a BQRP trigger frame on the first link and responds using a BQR frame on the first link / transmits a BQR frame; or the first multi-link device receives a BFRP trigger frame on the first link and responds using an NDP frame on the first link / transmits an NDP flake; or the first multi-link device receives a data frame or management frame on the first link and responds using an ACK frame on the first link / transmits an ACK frame; or the first multi-link device receives a data frame on the first link and responds using a BA frame on the first link / transmits a BA frame.In response to this, the second implementation may be alternatively described as follows: After transmitting a BSR frame, BQR frame, or NDP frame on the first link, the first multi-link device does not start the media synchronization delay timer with respect to the second link.

[0126]

[0144] After responding with / transmitting CTS frames, NDP frames, BSR frames, BQR frames, ACK frames, or BA frames on the first link, it is possible to understand that the first multi-link device is in a receiving state with respect to the first link. Therefore, reception on the first link does not affect channel contention performed on the second link. In this case, the first multi-link device may perform common channel contention on the second link, i.e., the energy detection threshold used in CCA operation is -62 dBm, or RTS / CTS frames may not be used to attempt to detect channel protection.

[0127]

[0142] In this embodiment of the present application, it is possible to know that after a non-STR MLD (i.e., the first multi-link device) receives an RTS (or MU-RTS) frame on the first link and responds with a CTS frame, the non-STR MLD does not start the mediumSyncDelay timer with respect to the second link. This makes it possible to improve the channel access efficiency or channel access success rate of the non-STR MLD with respect to the second link, or to increase the channel access opportunities of the non-STR MLD with respect to the second link.

[0128]

[0143] In this embodiment of the present application, when a specific type of frame is transmitted on the first link, the media synchronization delay timer is not started with respect to the second link. Therefore, if non-STR MLDs are in a blind / self-interfering state on some links, the channel access efficiency or channel access success rate of non-STR MLDs on these links can be improved, or the channel access opportunities for non-STR MLDs on these links can be increased.

[0129]

[0144] Embodiment 2 Embodiment 2 of the present invention describes a method by which a non-STR MLD performs channel access on a second link when the length of the PPDU transmitted on the first link is less than a preset value.

[0130]

[0145] Figure 5 is another schematic flowchart of a channel access method for a multi-link device according to an embodiment of the present invention. As shown in Figure 5, the channel access method for a multi-link device includes, but is not limited to, the following steps:

[0131]

[0146] S201: If the length of the first PPDU transmitted over the first link by the first multi-link device is less than or equal to a first value, the first multi-link device does not start the media synchronization delay timer with respect to the second link, where the first multi-link device is not permitted to transmit and receive simultaneously on the first and second links.

[0132]

[0147] The fact that the first multi-link device does not initiate a media synchronization delay timer with respect to the second link may be understood (or stated) as follows: if the first multi-link device performs channel contention with respect to the second link, the energy detection threshold used by the CCA operation is the first threshold; or, after the back-off counter backs off to 0 with respect to the second link, the first multi-link device is permitted to immediately transmit frames other than RTS and MU-RTS frames. In other words, after the back-off counter backs off to 0 with respect to the second link, the first multi-link device does not transmit RTS / MU-RTS frames in an attempt to detect channel protection / availability. The first threshold may be -62 dBm.

[0133]

[0148] Optionally, if the first multi-link device has transmitted the first PPDU on the first link and has started the mediumSyncDelay timer for the second link, the first multi-link device will close (or stop, or cancel) the mediumSyncDelay timer when it determines that the length of the first PPDU is less than or equal to a first value.

[0134]

[0149] Optionally, if the media sync delay timer for the second link is started, and the length of the first PPDU transmitted over the first link by the first multi-link device is less than or equal to a first value, the first multi-link device does not update the media sync delay timer for the second link.

[0135]

[0150] Optionally, if the media sync delay timer for the second link is started and the length of the PPDU transmitted over the first link by the first multi-link device is greater than a first value, the first multi-link device is required to update the media sync delay timer for the second link. Updating the media sync delay timer for the second link by the first multi-link device may be understood as: updating the media sync delay timer for the second link to the initial value of the media sync delay timer that existed when the media sync delay timer was started, which is equivalent to restarting the media sync delay timer for the second link. Conversely, not updating the media sync delay timer for the second link by the first multi-link device may be understood as: not updating the media sync delay timer for the second link to the initial value of the media sync delay timer that existed when the media sync delay timer was started.

[0136]

[0151] Optionally, the first value may be a fixed value specified in the protocol, for example, 50 μs, 100 μs, or 200 μs.

[0137]

[0152] Optionally, the first value may be 28 μs. 28 μs is the PPDU length present when the CTS and ACK frames are transmitted in 24 Mbps non-HT PPDU or 24 Mbps non-HT dual PPDU format.

[0138]

[0153] Optionally, the first value may be 32μs. 32μs is the PPDU length when a BA (block acknowledge, block ACK) frame with a bitmap length of 64 is transmitted in 24 Mbps non-HT PPDU or 24 Mbps non-HT duplex PPDU format.

[0139]

[0154] Optionally, the first value may be 44μs. 44μs is the PPDU length present when the CTS and ACK frames are transmitted in 6 Mbps non-HT PPDU or 6 Mbps non-HT duplex PPDU format.

[0140]

[0155] Optionally, the first value may be 40 μs. 40 μs is the PPDU length present when a BA frame with a bitmap length of 256 is transmitted in 24 Mbps non-HT PPDU or 24 Mbps non-HT duplex PPDU format.

[0141]

[0156] Optionally, the first value may be 36μs. 36μs is the PPDU length present when a QoS-Null frame is transmitted in 24 Mbps non-HT PPDU or 24 Mbps non-HT dual PPDU format.

[0142]

[0157] Optionally, the first value may be 68μs. 68μs is the PPDU length when a BA frame with a bitmap length of 64 is transmitted in 6 Mbps non-HT PPDU or 6 Mbps non-HT duplex PPDU format.

[0143]

[0158] Optionally, the first value may be determined by an access point (or AP MLD) and transmitted to a station (i.e., a non-AP MLD). Specifically, prior to step S201, the channel access method of the multi-link device in this embodiment of the present application may further include: step S202: a second multi-link device transmits instruction information, which is used to indicate the first value. In response, the first multi-link device receives the instruction information. The instruction information may be carried in a beacon frame, an association response frame, or a reassociation response frame. The first multi-link device may be a non-STR MLD, specifically a non-STR non-AP MLD. The second multi-link device may be an STR MLD, specifically an STR AP MLD.

[0144]

[0159] In implementation, instruction information may be placed in a multi-link element. Figure 6a is a schematic diagram of the frame structure of a multi-link element according to an embodiment of the present invention. As shown in Figure 6a, a multi-link element may include an element ID field, a length field, an element ID extension field, a multi-link control field, a medium sync delay timer threshold field, optional subelements fields, etc. The medium sync delay timer threshold field is used to indicate a first value.

[0145]

[0160] In another implementation, instruction information may be placed in an EHT operation element. Figure 6b is a schematic diagram of the frame structure of an EHT operation element according to an embodiment of the present invention. As shown in Figure 6b, the EHT operation element may include an element ID field, a length field, an element ID extension field, a medium sync delay timer threshold field, and the like. The medium sync delay timer threshold field is used to indicate a first value.

[0146]

[0161] In further implementations, a new information element may be defined to transmit instruction information. The new information element is used to transmit non-STR MLD configuration parameters. Optionally, the new information element may be referred to as a non-STR MLD parameter set element. It will be understood that the new information element may have a different name; this is not limited to this embodiment of the Application. Figure 6c is a schematic diagram of the frame structure of a non-STR MLD parameter set element according to an embodiment of the Application. As shown in Figure 6c, the non-STR MLD parameter set element may include an element ID field, a length field, an element ID extension field, a medium sync delay timer threshold field, etc. The medium sync delay timer threshold field is used to indicate a first value.

[0147]

[0162] Optionally, if the length of the first PPDU is greater than the first value, the first multi-link device may initiate a media synchronization delay timer with respect to the second link. While the media synchronization delay timer is operating, the first multi-link device may use a more conservative channel access mechanism with respect to the second link. A more conservative channel access mechanism includes, but is not limited to, (1) using a low energy detection threshold (here, an ED threshold lower than -62 dBm) to determine if the channel is busy; and (2) requiring the transmission of an RTS frame to attempt to detect the channel's availability. Optionally, this may be a one-time attempt (or a one-time transmission of an RTS frame) or a limited number of attempts. If the length of the first PPDU is equal to the first value, the operation performed by the first multi-link device may be understood as either not initiating the media synchronization delay timer with respect to the second link, or initiating the media synchronization delay timer with respect to the second link. In embodiments of the present application, the operation performed by the first multi-link device when the length of the first PPDU is equal to a first value may be set based on actual circumstances.

[0148]

[0163] Optionally, before initiating the media sync delay timer for the second link, the first multi-link device may determine an initial value for the media sync delay timer, which corresponds to the length of the first PPDU. It will be understood that the initial value of the media sync delay timer initiated by the first multi-link device for the second link is the determined initial value corresponding to the length of the first PPDU.

[0149]

[0164] The mapping relationship between the length of the PPDU and the initial value (or initial period) of the media synchronization delay timer may be defined in a standard protocol. Alternatively, the second multi-link device transmits first instruction information before the first multi-link device transmits the first PPDU on the first link. In response, the first multi-link device receives the first instruction information. The first instruction information is used to indicate the mapping relationship between the PPDU length and the initial value (or initial period) of the media synchronization delay timer.

[0150]

[0165] Optionally, after or at the time the media synchronization delay timer is started for the second link, the first multi-link device determines an energy detection threshold corresponding to the length of the first PPDU, and if channel contention is performed on the second link, the first multi-link device sets the energy detection threshold used in the CCA operation to the threshold corresponding to the length of the first PPDU.

[0151]

[0166] The mapping relationship between PPDU length and energy detection threshold may be defined by a standard protocol. Alternatively, a second multi-link device transmits second instruction information before the first multi-link device transmits the first PPDU over the first link. In response, the first multi-link device receives the second instruction information. The second instruction information is used to indicate the mapping relationship between PPDU length and energy detection threshold.

[0152]

[0167] It will be understood that the first and second instruction information may be part of the instruction information. That is, part of the instruction information may indicate both the mapping relationship between the length of the PPDU and the initial value (or initial period) of the media synchronization delay timer, and the mapping relationship between the length of the PPDU and the energy detection threshold. In other words, the first and second instruction information are carried within the frame.

[0153]

[0168] In this embodiment of the present application, it is possible to know that a non-STR MLD is restricted from initiating a mediumSyncDelay timer on another link after transmitting a short frame on one link; or that the energy detection threshold used in the CCA is set to -62 dBm when channel contention occurs on another link; or that it is not necessary to use an RTS frame on another link to attempt to detect channel protection / availability. Thus, the channel access efficiency or channel access success rate of a non-STR MLD on another link is improved, and the channel access opportunities for a non-STR MLD on another link are increased.

[0154]

[0169] In an optional embodiment, “length of the first PPDU” can be replaced with “length of the medium access control (MAC) frame in the first PPDU.” Correspondingly, step S301 may be replaced as follows: If the length of the MAC frame of the first PPDU transmitted over the first link by the first multi-link device is less than or equal to a second value, the first multi-link device does not start the medium synchronization delay timer with respect to the second link, where the first multi-link device is not permitted to transmit and receive simultaneously on the first and second links.

[0155]

[0170] In another optional embodiment, the channel access method provided in Embodiments 1 and 2 can be further applied to single-link and multi-access channel scenarios. Two channels are used as an example. It is assumed that the AP can use two channels for channel access, but can only complete access on one channel at a time, and cannot access both channels simultaneously. Specifically, the AP performs channel contention on the primary channel, for example, the first channel. If the primary channel is busy, the AP can switch to the other channel (for example, the second channel) and perform channel contention. After the back-off counter for the second channel is backed off to 0, the AP performs transmission on the second channel.

[0156]

[0171] With regard to single-link and multi-access channel scenarios, this embodiment of the present application proposes that after the AP transmits a short frame (e.g., an RTS frame, CTS frame, block acknowledge (BA) frame, BSR frame, BQR frame, PS-Poll frame, or NDP frame) on a second channel, the AP does not start a timer with respect to the first channel. The timer may be a medium synchronization delay timer. Optionally, this embodiment of the present application further proposes that the AP transmits a first PPDU on the second channel; and if the PPDU length of the first PPDU is less than or equal to a first value, the AP does not start a medium synchronization delay timer with respect to the first channel.

[0157]

[0172] Optionally, the fact that the AP does not start a timer for the first channel may be understood (or stated) as follows: when the AP performs channel contention for the first channel, the energy detection threshold used by the CCA operation is the first threshold; or, after the back-off counter for the first channel has backed off to 0, the AP is permitted to immediately transmit frames other than RTS and MU-RTS frames. In other words, after the back-off counter for the first channel has backed off to 0, the AP does not transmit RTS / MU-RTS frames to attempt to detect channel protection / availability. The first threshold may be -62 dBm.

[0158]

[0173] It will be understood that the second channel in this embodiment of the present application is equivalent to the first link in Embodiments 1 and 2, and the first channel in this embodiment of the present application is equivalent to the second link in Embodiments 1 and 2.

[0159]

[0174] It can be seen that the channel access method provided in this embodiment of the present application may be further applicable to single-link and multi-access channel scenarios, thereby extending the scenarios of the method and improving the channel access success rate or channel access efficiency of the AP with respect to the first channel.

[0160]

[0175] Embodiment 3 Embodiment 3 of the present invention provides a method for determining the initial period of a media synchronization delay timer. According to the method for determining the initial period of a media synchronization delay timer, the initial period of the media synchronization delay timer is determined based on the length of frames transmitted on a first link (or second channel).

[0161]

[0176] Figure 7 is a schematic flowchart of a method for determining the initial period of a media synchronization delay timer according to an embodiment of the present invention. As shown in Figure 7, the method for determining the initial period of a media synchronization delay timer includes, but is not limited to, the following steps.

[0162]

[0177] S301: A second multi-link device transmits first instruction information, which is used to indicate a mapping relationship between the PPDU length / byte length and the initial value (or initial period) of the media synchronization delay timer.

[0163]

[0178] Specifically, the second multi-link device may be an AP MLD, which has STR capabilities. The AP MLD may transmit first instruction information on the first link or another link, this is not limited to this embodiment of the application. The first instruction information may be used to indicate a mapping relationship between the PPDU length and the initial value (or initial period) of the media synchronization delay timer.

[0164]

[0179] In one example, Figure 8 is a schematic diagram of the mapping relationship between the PPDU length and the initial value of the media synchronization delay timer according to an embodiment of the present invention. As shown in Figure 8, when the PPDU length is within the range of 0 to 100 μs (microseconds) (i.e., interval [0,100 μs], interval (0,100 μs), interval (0,100 μs], or interval [0,100 μs]), the initial value of the media synchronization delay timer is 0 ms; when the PPDU length is within the range of 100 μs to 1 ms (i.e., interval [100,1000 μs], interval (100,1000 μs), interval (100,1000 μs], or interval [100,1000 μs]), the initial value of the media synchronization delay timer is 3 ms; and when the PPDU length is 1 ms or more, the initial value of the media synchronization delay timer is 6 ms.

[0165]

[0180] The mapping relationships shown in Figure 8 can be summarized as shown in Table 1 below: Table 1

[0166] [Table 1]

[0181] The mapping relationships shown in Figure 8 and Table 1 are merely examples, and it will be understood that in actual applications, the mapping relationships can be determined based on the actual application scenario. For example, the mapping relationships may alternatively be as follows: when the PPDU length is 50 μs or less, the initial value of the media synchronization delay timer is 0 ms; when the PPDU length is 50 μs or more and 200 μs or less, the initial value of the media synchronization delay timer is 1 ms; when the PPDU length is 200 μs or more and 500 μs or less, the initial value of the media synchronization delay timer is 3 ms; and when the PPDU length is 500 μs or more, the initial value of the media synchronization delay timer is 5 ms. This is not limited to this embodiment of the present application.

[0167]

[0182] Optionally, the first instruction information may include an array. For example, the array (0,100,0) indicates that the initial value of the media synchronization delay timer is 0ms when the PPDU length is in the range of 0 to 100μs; the array (100,1000,3) indicates that the initial value of the media synchronization delay timer is 3ms when the PPDU length is in the range of 100μs to 1ms; and the array (1000,Max PPDU Length,6) indicates that the initial value of the media synchronization delay timer is 6ms when the PPDU length is in the range of 1ms to the Max PPDU Length. The Max PPDU Length is defined in the standard protocol.

[0168]

[0183] Optionally, the first instruction information may include two fields. The first field is used to determine N intervals. The second field is used to indicate the initial value of the media synchronization delay timer, which corresponds to the initial value of each of the N intervals.

[0169]

[0184] The first field may contain N+1 subfields. The values ​​of the N+1 subfields increase monotonically, and the values ​​of two adjacent subfields can determine an interval. Thus, the N+1 subfields can determine N intervals. For example, the value of the first subfield is 0, and the value of the (N+1)th subfield is the maximum PPDU length, or a value greater than the maximum PPDU length, e.g., 6ms. Optionally, the first subfield (or the (N+1)th subfield) does not have to be carried by the first field.

[0170]

[0185] The second field contains N subfields. The values ​​of the subfields are the initial values ​​of the media synchronization delay timer, representing the initial values ​​corresponding to the interval.

[0171]

[0186] S302: The first multi-link device receives the first instruction information.

[0172]

[0187] S303: The first multi-link device determines an initial value for the media synchronization delay timer, which corresponds to the length of the first PPDU transmitted over the first link, based on the length of the first PPDU. The initial value is used to determine whether to start the media synchronization delay timer with respect to the second link. The first multi-link device is not permitted to transmit or receive simultaneously on the first and second links.

[0173]

[0188] Specifically, the first multi-link device may be a non-AP MLD, and a non-AP MLD has non-STR capability. The first multi-link device can determine the initial value (or initial period) of the media synchronization delay timer, which corresponds to the PPDU length of the first PPDU, based on a mapping relationship between the PPDU length and the initial value (or initial period) of the media synchronization delay timer, as indicated by the first instruction information, and based on the PPDU length of the first PPDU. For example, the mapping relationship is shown in Table 1 above, and it is assumed that the length of the first PPDU is 200 μs. In this case, the initial value (or initial period) of the media synchronization delay timer is 3 ms.

[0174]

[0189] Optionally, the first multi-link device determines whether to start the media sync delay timer for the second link based on the initial value (or initial period) of the media sync delay timer, which corresponds to the length of the first PPDU.

[0175]

[0190] Specifically, if the initial value (or initial period) of the media synchronization delay timer is equal to 0, the first multi-link device does not start the media synchronization delay timer for the second link; or, if the initial value (or initial period) of the media synchronization delay timer is greater than 0, the first multi-link device starts the media synchronization delay timer for the second link. The initial value / initial period of the media synchronization delay timer is the value determined in step S404.

[0176]

[0191] The fact that the first multi-link device initiates a mediumSyncDelay timer with respect to the second link may be understood (or stated) as follows: During the period in which the mediumSyncDelay timer is operating, the first multi-link device may use a more conservative channel access mechanism with respect to the second link. A more conservative channel access mechanism may include, but is not limited to, (1) using a low-energy detection threshold (here, an ED threshold lower than -62 dBm) to determine whether the channel is busy; and (2) it is essential to transmit an RTS frame in an attempt to detect the channel's availability. Optionally, this may be a one-time attempt (or a one-time transmission of an RTS frame) or a limited number of attempts.

[0177]

[0192] The fact that the first multi-link device does not start the mediumSyncDelay timer with respect to the second link may be understood (or can be stated) as follows: when the first multi-link device performs channel contention on the second link, the energy sensing threshold used by the CCA operation is the first threshold; or, after the back-off counter for the second link has backed off to 0, the first multi-link device is permitted to immediately transmit frames other than RTS frames and MU-RTS frames. The first threshold may be -62 dBm.

[0178]

[0193] It will be understood that the method for determining the initial period of the media synchronization delay timer provided in this embodiment of the present application may, alternatively, be applied to single-link and multi-access channel scenarios. In the single-link and multi-access channel scenario, the first channel corresponds to the second link, and the second channel corresponds to the first link. Further details are not described again here.

[0179]

[0194] In this embodiment of the present application, the mapping relationship between the PPDU length and the initial value (or initial period) of the medium sync delay timer is indicated by first instruction information, and as a result, the first multi-link device can determine an initial value of the medium sync delay timer corresponding to the length of the first PPDU based on the mapping relationship and the length of the first PPDU transmitted on the first link, and know that if the initial value is equal to 0, the mediumSyncDelay timer will not be started for the second link, and if the initial value is greater than 0, the mediumSyncDelay timer will be started for the second link. Different PPDU lengths correspond to different initial values ​​of the mediumSyncDelay timer, allowing for more flexible setting of the mediumSyncDelay timer and improving channel access efficiency.

[0180]

[0195] In an optional embodiment, the mapping relationship between the PPDU length and the initial value (or initial period) of the media synchronization delay timer may be defined by a standard protocol. If the mapping relationship is defined by a standard protocol, the method for determining the initial period of the media synchronization delay timer shown in Figure 7 may not include steps S301 and S302, and may include step S303.

[0181]

[0196] Embodiment 4 Embodiment 4 of the present invention provides a method for determining an energy detection threshold in a CCA process. According to the method for determining an energy detection threshold in a CCA process, the ED threshold used in the CCA process when back-off is performed with respect to the second link in mediumSyncDelay is determined based on the length of the frame transmitted on the first link (or second channel).

[0182]

[0197] Figure 9 is a schematic flowchart of a method for determining an energy detection threshold in a CCA process according to an embodiment of the present invention. As shown in Figure 9, the method for determining an energy detection threshold in a CCA process includes, but is not limited to, the following steps.

[0183]

[0198] S401: A second multi-link device transmits second instruction information, which is used to indicate a mapping relationship between the PPDU length and the energy detection threshold.

[0184]

[0199] Specifically, the second multi-link device may be an AP MLD, which has STR capability. The AP MLD may transmit second instruction information on the first link or another link. This is not limited to this embodiment of the present application. The second instruction information may be used to indicate a mapping relationship between PPDU length and energy detection threshold.

[0185]

[0200] In one example, Figure 10 is a schematic diagram of the mapping relationship between PPDU length and energy detection threshold according to an embodiment of the present invention. As shown in Figure 10, when the PPDU length is within the range of 0 to 100 μs (microseconds) (i.e., interval [0,100 μs], interval (0,100 μs), interval (0,100 μs], or interval [0,100 μs]), the energy detection threshold is -62 dBm; when the PPDU length is within the range of 100 μs to 1 ms (i.e., interval [100,1000 μs], interval (100,1000 μs), interval (100,1000 μs], or interval [100,1000 μs]), the energy detection threshold is -72 dBm; and when the PPDU length is 1 ms or more, the energy detection threshold is -82 dBm.

[0186]

[0201] The mapping relationships shown in Figure 10 can be summarized as shown in Table 2 below: Table 2

[0187] [Table 2]

[0202] The mapping relationships shown in Figure 10 and Table 2 are merely examples, and it will be understood that in actual applications, the mapping relationships can be determined based on the actual application scenario. For example, the mapping relationships may alternatively be as follows: when the PPDU length is 50 μs or less, the energy detection threshold is -62 dBm; when the PPDU length is 50 μs or more and 200 μs or less, the energy detection threshold is -67 dBm; when the PPDU length is 200 μs or more and 500 μs or less, the energy detection threshold is -72 dBm; and when the PPDU length is 500 μs or more, the energy detection threshold is -82 dBm. This is not limited to this embodiment of the present application.

[0188]

[0203] Optionally, the second instruction information may include a sequence. For example, the sequence (0,100,-62) indicates that the energy detection threshold is -62 dBm when the PPDU length is in the range of 0 to 100 μs; the sequence (100,1000,-72) indicates that the energy detection threshold is -72 dBm when the PPDU length is in the range of 100 μs to 1 ms; and the sequence (1000,Max PPDU Length,-82) indicates that the energy detection threshold is -82 dBm when the PPDU length is in the range of 1 ms to the Max PPDU Length. The Max PPDU Length is defined in the standard protocol.

[0189]

[0204] Optionally, the second instruction information may include two fields. The second field is used to determine N intervals. The second field is used to indicate the initial value corresponding to each of the N intervals.

[0190]

[0205] The first field may contain N+1 subfields. The values ​​of the N+1 subfields increase monotonically, and the values ​​of two adjacent subfields can determine an interval. Thus, the N+1 subfields can determine N intervals. For example, the value of the first subfield is 0, and the value of the (N+1)th subfield is the maximum PPDU length, or a value greater than the maximum PPDU length, e.g., 6ms. Optionally, the first subfield (or the (N+1)th subfield) does not have to be carried by the first field.

[0191]

[0206] The second field contains N subfields. The values ​​of the subfields represent the energy detection threshold corresponding to the interval.

[0192]

[0207] S402: The first multi-link device receives the second instruction information.

[0193]

[0208] S403: The first multi-link device determines an energy detection threshold corresponding to the length of the first PPDU, based on the length of the first PPDU transmitted over the first link. The energy detection threshold is used to determine whether to start the medium synchronization delay timer with respect to the second link.

[0194]

[0209] Specifically, the first multi-link device may be a non-AP MLD, and a non-AP MLD has non-STR capability. The first multi-link device can determine the energy detection threshold corresponding to the length of the first PPDU based on a mapping relationship between the PPDU length and the energy detection threshold, indicated by the second instruction information, and based on the PPDU length of the first PPDU. For example, the mapping relationship is shown in Table 2 above, and it is assumed that the length of the first PPDU is 200 μs. In this case, the energy detection threshold is -72 dBm.

[0195]

[0210] Optionally, the first multi-link device determines whether to start the medium sync delay timer for the second link based on an energy detection threshold corresponding to the length of the first PPDU. Specifically, if the energy detection threshold determined in step S403 is equal to -62 dBm, the first multi-link device does not start the medium sync delay timer for the second link; or, if the energy detection threshold determined in step S403 is less than -62 dBm, the first multi-link device starts the medium sync delay timer for the second link. If the first multi-link device starts the medium sync delay timer for the second link, it means that during the mediumSyncDelay period, the first multi-link device sets the energy detection threshold used in the CCA to the energy detection threshold corresponding to the length of the first PPDU (i.e., the energy detection threshold determined in step S504) when performing channel contention for the second link.

[0196]

[0211] The fact that the first multi-link device initiates a mediumSyncDelay timer with respect to the second link may be understood (or stated) as follows: During the duration of the mediumSyncDelay timer, the first multi-link device may use a more conservative channel access mechanism with respect to the second link. A more conservative channel access mechanism may include, but is not limited to, (1) using a low-energy detection threshold (here, an ED threshold lower than -62 dBm) to determine whether the channel is busy; and (2) it is essential to transmit an RTS frame to attempt to detect the channel's availability. Optionally, this may be a one-time attempt (or a one-time transmission of an RTS frame) or a limited number of attempts.

[0197]

[0212] The fact that the first multi-link device does not start the mediumSyncDelay timer with respect to the second link may be understood (or can be stated) as follows: when the first multi-link device performs channel contention on the second link, the energy sensing threshold used by the CCA operation is the first threshold; or, after the back-off counter for the second link has backed off to 0, the first multi-link device is permitted to immediately transmit frames other than RTS frames and MU-RTS frames. The first threshold may be -62 dBm.

[0198]

[0213] It will be understood that the method for determining the energy detection threshold in a CCA process provided in this embodiment of the present application may, alternatively, be applied to single-link and multi-access channel scenarios. In the single-link and multi-access channel scenario, the first channel corresponds to the second link, and the second channel corresponds to the first link. Further details are not described again here.

[0199]

[0214] In this embodiment of the present application, the mapping relationship between PPDU length and energy detection threshold is indicated by second instruction information, and as a result, the first multi-link device can determine the energy detection threshold corresponding to the length of the first PPDU based on the mapping relationship and the length of the first PPDU transmitted over the first link, and know that if the energy detection threshold is equal to -62 dBm, the mediumSyncDelay timer will not be started for the second link, and if the energy detection threshold is greater than -62 dBm, the mediumSyncDelay timer will be started for the second link. Different PPDU lengths correspond to different energy detection thresholds. In this case, the channel access mechanism used for the second link is more flexible and improves channel access efficiency.

[0200]

[0215] In an optional embodiment, the mapping relationship between PPDU length and energy detection threshold may be defined by a standard protocol. If the mapping relationship is defined by a standard protocol, the method for determining the energy detection threshold in the CCA process shown in Figure 9 may not include steps S404 and S402, and may include step S403.

[0201]

[0216] In an optional alternative embodiment, the first instruction information in Embodiment 3 and the second instruction information in Embodiment 4 may be part of the instruction information, or the first and second instruction information may be carried in the same frame. Thus, Embodiments 3 and 4 may be combined into some embodiment. Specifically, a second multi-link device transmits instruction information, which is used to indicate a mapping relationship between the PPDU length and the initial value (or initial period) of the media synchronization delay timer, and a mapping relationship between the PPDU length and the energy detection threshold; a first multi-link device receives the instruction information; the first multi-link device transmits a first PPDU over the first link; and the first multi-link device determines, based on the length of the first PPDU, an initial value of the media synchronization delay timer corresponding to the length of the first PPDU, and an energy detection threshold corresponding to the length of the first PPDU. Optionally, the first multi-link device may further determine whether to start the media synchronization delay timer with respect to the second link based on an energy detection threshold corresponding to the length of the first PPDU, or based on an initial value of the media synchronization delay timer that corresponds to the length of the first PPDU.

[0202]

[0217] The above description details the method provided in this application. To better implement the aforementioned solution in the embodiments of this application, embodiments of this application further provide corresponding apparatus or devices.

[0203]

[0218] In embodiments of the present application, the communication device may be divided into functional modules based on the method examples described above. For example, each functional module may be divided according to its respective function, or two or more functions may be integrated into a single processing module. The integrated module may be implemented in hardware form or in the form of a software functional module. It should be noted that the module division in embodiments of the present application is merely an example and a logical functional division, and other division methods may exist in actual implementation.

[0204]

[0219] When an integrated unit is used, Figure 11 is a schematic diagram of the structure of a first multi-link device according to an embodiment of the present invention. As shown in Figure 11, the first multi-link device includes a transceiver unit 11 and a processing unit 12.

[0205]

[0220] In the design, the processing unit 12 is configured to skip starting the media synchronization delay timer for the second link if the length of the first PPDU transmitted over the first link by the first multi-link device is less than or equal to a first value. The first multi-link device is not permitted to perform simultaneous transmission and reception with respect to the first and second links.

[0206]

[0221] Specifically, the processing unit 12 is configured to set the energy detection threshold used by the CCA operation to a first threshold when channel contention occurs with respect to the second link. Alternatively, the transceiver unit 11 is configured to transmit frames other than RTS frames and MU-RTS frames after the back-off counter has backed off to 0 with respect to the second link. The first threshold may be -62 dBm.

[0207]

[0222] The first multi-link device in this design is capable of correspondingly performing Embodiment 2, and it should be understood that the operation or function of the units in the first multi-link device are individually used to perform the corresponding operations performed by the first multi-link device in Embodiment 2. For brevity, further details will not be described again here.

[0208]

[0223] In the design, the processing unit 12 is configured to skip starting the media synchronization delay timer for the second link if the type of the first frame transmitted over the first link by the first multi-link device is of type 1. The first multi-link device is not permitted to perform simultaneous transmission and reception over the first and second links.

[0209]

[0224] Specifically, the processing unit 12 is configured to set the energy detection threshold used by the CCA operation to a first threshold when channel contention occurs with respect to the second link. Alternatively, the transceiver unit 11 is further configured to transmit frames other than RTS frames and MU-RTS frames after the back-off counter has backed off to 0 with respect to the second link. The first threshold may be -62 dBm.

[0210]

[0225] The first multi-link device in this design is capable of performing Embodiment 1 accordingly, and it should be understood that the operation or function of the units in the first multi-link device is used individually to perform the corresponding operation performed by the first multi-link device in Embodiment 1. For brevity, further details will not be described again here.

[0211]

[0226] In the design, the transceiver unit 11 is configured to receive first instruction information, which is used to indicate a mapping relationship between the PPDU length and the initial value of the media synchronization delay timer; the processing unit 12 is configured to determine an initial value of the media synchronization delay timer, which corresponds to the length of the first PPDU, based on the length of the first PPDU transmitted over the first link. The initial value is used to determine whether to start the media synchronization delay timer with respect to the second link. The first multi-link device is not permitted to perform simultaneous transmission and reception with respect to the first and second links.

[0212]

[0227] Optionally, the processing unit 12 is further configured to determine whether to start the media synchronization delay timer with respect to the second link based on an initial value of the media synchronization delay timer, which corresponds to an initial value of the first PPDU length.

[0213]

[0228] Optionally, the processing unit 12 is configured to: skip starting the media synchronization delay timer for the second link if the determined initial value of the media synchronization delay timer is equal to 0; or start the media synchronization delay timer for the second link if the determined initial value of the media synchronization delay timer is equal to 0.

[0214]

[0229] The first multi-link device in this design is capable of correspondingly performing Embodiment 3, and it should be understood that the operation or function of the units in the first multi-link device is used individually to perform the corresponding operation performed by the first multi-link device in Embodiment 3. For brevity, further details will not be described again here.

[0215]

[0230] In the design, the transceiver unit 11 is configured to receive a second instruction information, which is used to specify a mapping relationship between the PPDU length and the energy detection threshold; and the processing unit 12 is configured to determine an initial value for the medium synchronization delay timer, which corresponds to the length of the first PPDU, based on the length of the first PPDU transmitted over the first link. The communication device is not permitted to perform simultaneous transmission and reception with respect to the first and second links.

[0216]

[0231] Optionally, the processing unit 12 is further configured to determine whether to start a media synchronization delay timer for a second link based on an energy detection threshold corresponding to the length of the first PPDU.

[0217]

[0232] Optionally, the processing unit 12 is configured to: skip starting the media synchronization delay timer for the second link if the determined energy detection threshold is equal to -62 dBm; or start the media synchronization delay timer for the second link if the determined energy detection threshold is less than -62 dBm.

[0218]

[0233] The first multi-link device in this design is capable of correspondingly performing Embodiment 4, and it should be understood that the operation or function of the units in the first multi-link device is used individually to perform the corresponding operation performed by the first multi-link device in Embodiment 4. For brevity, further details will not be described again here.

[0219]

[0234] Figure 12 is a schematic diagram of the structure of a second multi-link device according to an embodiment of the present invention. As shown in Figure 12, the second multi-link device includes transceiver unit 21 and transceiver unit 22.

[0220]

[0235] In the design, the processing unit 21 is configured to generate first instruction information, which is used to indicate a mapping relationship between the PPDU length and the initial value (or initial period) of the media synchronization delay timer; and the transceiver unit 22 is configured to transmit the first instruction information.

[0221]

[0236] The second multi-link device in this design is capable of correspondingly performing Embodiment 3, and it should be understood that the operation or function of the units in the second multi-link device are individually used to perform the corresponding operation performed by the second multi-link device in Embodiment 3. For brevity, further details will not be described again here.

[0222]

[0237] In an alternative design, processing unit 21 is configured to generate second instruction information, which is used to indicate a mapping relationship between PPDU length and energy detection threshold; and transceiver unit 22 is configured to transmit the second instruction information.

[0223]

[0238] The second multi-link device in this design is capable of correspondingly performing Embodiment 4, and it should be understood that the operation or function of the units in the second multi-link device is used individually to perform the corresponding operation performed by the second multi-link device in Embodiment 4. For the sake of brevity, further details will not be described again here.

[0224]

[0239] The above describes the first and second multi-link devices in embodiments of the present application. The following describes possible product forms of the first and second multi-link devices. It should be understood that any product having the functionality of the first multi-link device shown in Figure 11, and any product having the functionality of the second multi-link device shown in Figure 12, are within the scope of protection of embodiments of the present application. It should be further understood that the following description is merely an example, and the product forms of the first and second multi-link devices in embodiments of the present application are not limited to these.

[0225]

[0240] In possible product configurations, the first and second multi-link devices described in the embodiments of this application may be implemented by a general-purpose bus architecture.

[0226]

[0241] The first multi-link device includes a processor and a transceiver that communicates with the processor via an internal connection.

[0227]

[0242] In the design, the processor is configured to skip starting the medium synchronization delay timer for the second link if the length of the first PPDU transmitted over the first link by the first multi-link device is less than or equal to a first value. The first multi-link device is not permitted to transmit and receive simultaneously on the first and second links. Optionally, the transceiver is configured to transmit the first PPDU over the first link.

[0228]

[0243] In the design, the processor is configured to skip starting the medium synchronization delay timer with respect to the second link if the type of the first frame transmitted over the first link by the first multi-link device is of type 1. The first multi-link device is not permitted to transmit and receive simultaneously on the first and second links.

[0229]

[0244] In the design, the transceiver is configured to receive first instruction information, which is used to indicate a mapping relationship between the length of the PPDU and the initial value of the media synchronization delay timer; and the processor is configured to determine an initial value of the media synchronization delay timer, which corresponds to the length of the first PPDU, based on the length of the first PPDU transmitted over the first link. The initial value is used to determine whether to start the media synchronization delay timer with respect to the second link. The first multi-link device is not permitted to transmit and receive simultaneously on the first and second links.

[0230]

[0245] In the design, the transceiver is configured to receive a second instruction information, which is used to indicate a mapping relationship between PPDU length / byte length and an energy detection threshold; and the processor is configured to determine an initial value for the medium synchronization delay timer, which corresponds to the length of the first PPDU, based on the length of the first PPDU transmitted over the first link. The communication device is not permitted to transmit or receive simultaneously over the first and second links.

[0231]

[0246] The second multi-link device includes a processor and transceivers that communicate with the processor via an internal connection.

[0232]

[0247] In the design, the processor is configured to generate first instruction information, which is used to indicate a mapping relationship between the PPDU length and the initial value (or initial period) of the media synchronization delay timer; and the transceiver is configured to transmit the first instruction information.

[0233]

[0248] In another design, the processor is configured to generate second instruction information, which is used to indicate a mapping relationship between the PPDU length and the energy detection threshold; and the transceiver is configured to transmit the second instruction information.

[0234]

[0249] In possible product configurations, the first multi-link device and the second multi-link device described in the embodiments of this application may be implemented by a chip.

[0235]

[0250] The chip implementing the first multi-link device includes processing circuits and input / output interfaces that communicate with the processing circuits via internal connections.

[0236]

[0251] In the design, the input / output interface is configured to receive code instructions and transmit the code instructions to the processing circuit; the processing circuit is configured to skip starting the medium synchronization delay timer for the second link if the length of the first PPDU transmitted over the first link is less than or equal to a first value. The first multi-link device is not permitted to transmit and receive simultaneously over the first and second links.

[0237]

[0252] In the design, the input / output interface is configured to receive code instructions and transmit the code instructions to the processing circuit; the processing circuit is configured to skip starting the medium synchronization delay timer with respect to the second link if the type of the first frame transmitted over the first link by the first multi-link device is of type 1. The first multi-link device is not permitted to transmit and receive simultaneously over the first and second links.

[0238]

[0253] In the design, the transceiver is configured to receive first instruction information, the input / output interface is configured to receive the first instruction information from the transceiver and transmit the first instruction information to a processing circuit for processing, obtaining a mapping relationship between the PPDU length and the initial value (or initial period) of the media synchronization delay timer, which is indicated by the first instruction information; and the processing circuit is configured to determine an initial value of the media synchronization delay timer, which corresponds to the length of the first PPDU, based on the length of the first PPDU transmitted over the first link. The initial value is used to determine whether to start the media synchronization delay timer with respect to the second link. The first multi-link device is not permitted to transmit and receive simultaneously on the first and second links.

[0239]

[0254] In the design, the transceiver is configured to receive second instruction information, the input / output interface is configured to receive the second instruction information from the transceiver and transmit the second instruction information to a processing circuit for processing, obtaining a mapping relationship between the PPDU length and an energy detection threshold, which is indicated by the second instruction information; and the processing circuit is configured to determine an energy detection threshold corresponding to the length of the first PPDU based on the length of the first PPDU transmitted over the first link. The energy detection threshold is used to determine whether to start a medium synchronization delay timer with respect to the second link. The first multi-link device is not permitted to transmit and receive simultaneously on the first and second links.

[0240]

[0255] The chip implementing the second multi-link device includes processing circuits and input / output interfaces that communicate with the processing circuits via internal connections.

[0241]

[0256] In the design, the input / output interface is configured to receive code instructions and transmit the code instructions to a processing circuit; the processing circuit is configured to generate first instruction information, which is used to indicate a mapping relationship between the PPDU length and the initial value (or initial period) of the media synchronization delay timer; the input / output interface is configured to transmit the first instruction information to a transceiver; and the transceiver is configured to transmit the first instruction information.

[0242]

[0257] In another design, the input / output interface is configured to receive a code instruction and transmit the code instruction to a processing circuit; the processing circuit is configured to generate a second instruction information, which is used to indicate a mapping relationship between the PPDU length and the energy detection threshold; the input / output interface is configured to transmit the second instruction information to a transceiver; and the transceiver is configured to transmit the second instruction information.

[0243]

[0258] In possible product configurations, the first multi-link device and the second multi-link device described in the embodiments of this application may be implemented by alternatively using one or more FPGAs (field programmable gate arrays), PLDs (programmable logic devices), controllers, state machines, gate logic, individual hardware components, or any other suitable circuitry or any combination of circuits capable of performing the various functions described throughout this application.

[0244]

[0259] It should be understood that various forms of communication devices have some function as either the first or second multi-link device in the embodiments of the method described above. Further details will not be explained again here.

[0245]

[0260] Embodiments of the present invention further provide a computer-readable storage medium. The computer-readable storage medium stores instructions, and when the instructions are executed on a computer, the computer can perform any of the methods in the embodiments described above.

[0246]

[0261] Embodiments of the present invention further provide a computer program product. When the computer program product is executed on a computer, the computer becomes capable of performing any of the methods in the embodiments described above.

[0247]

[0262] Embodiments of the present invention further provide a communication device. The device may exist in the form of a chip. The structure of the device includes a processor and an interface circuit. The processor is configured to communicate with other devices via the interface circuit, and as a result the device performs any of the methods in the embodiments described above.

[0248]

[0263] Methods or algorithmic steps described in combination with the contents disclosed herein may be implemented by hardware or by a processor by executing software instructions. Software instructions may include corresponding software modules. Software modules can be stored in random access memory (RAM), flash memory, erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), registers, hard disk drives, removable hard disks, compact disk read-only memory (CD-ROM), or any other form of storage medium well known in the art. For example, the storage medium may be coupled to a processor, as a result of which the processor can read information from or write information to the storage medium. Of course, the storage medium may also be a component of the processor. The processor and storage medium may be located in an ASIC. Furthermore, the ASIC may be located in a core network interface device. Of course, the processor and storage medium may exist as separate components within the core network interface device.

[0249]

[0264] Those skilled in the art will notice that, in one or more of the above-mentioned examples, the functions described in this application may be implemented by hardware, software, firmware, or any combination thereof. If this application is implemented by software, the above-mentioned functions may be stored on a computer-readable medium or transmitted as one or more instructions or codes on a computer-readable medium. Computer-readable mediums include computer-readable storage media and communication media. Communication media include any medium that enables computer programs to be transmitted from one location to another. Storage media may be any available medium accessible to a general-purpose or dedicated computer.

[0250]

[0265] The objectives, technical solutions, and advantages of the present application are described in more detail in the specific embodiments described above. It should be understood that the foregoing description is merely a specific implementation of the present application and is not intended to limit the scope of protection of the present application. Any modifications, equivalent substitutions, or improvements made based on the technical solutions of the present application shall also be included within the scope of protection of the present application.

Claims

1. A channel access method for multi-link devices: A method comprising the steps of: if the length of a first physical layer protocol data unit PPDU transmitted over a first link by a first multilink device is less than or equal to a first value, the first multilink device skips starting a media synchronization delay timer with respect to a second link, and the first multilink device sets an energy detection threshold used by a clear channel evaluation (CCA) performed with respect to the second link to -62 dBm.

2. A method according to claim 1, wherein the first multi-link device is not permitted to perform simultaneous transmission and reception with respect to the first link and the second link.

3. The method according to claim 1 or 2, further: A method comprising the step of the first multi-link device receiving the first value, wherein the first value is carried in a beacon frame, an association response frame, or a reassociation response frame.

4. The method according to claim 1 or 2, further: A method comprising the steps of: when the length of the first PPDU is greater than the first value, the first multi-link device determines an initial value for the media synchronization delay timer that corresponds to the length of the first PPDU, and starts the media synchronization delay timer with respect to the second link using the initial value.

5. The method according to claim 4, further: A method comprising the step of a first multi-link device receiving first instruction information, wherein the first instruction information is used to indicate a mapping relationship between the PPDU length and the initial value of the media synchronization delay timer.

6. The first multi-link device is: A first multi-link device including a processing unit configured to skip starting a media synchronization delay timer for a second link and to set an energy detection threshold used by a clear channel evaluation (CCA) performed for the second link to -62 dB when the length of a first PPDU transmitted over a first link by the first multi-link device is less than or equal to a first value.

7. A first multi-link device according to claim 6, wherein the first multi-link device is not permitted to perform simultaneous transmission and reception with respect to the first link and the second link.

8. The first multi-link device according to claim 6 or 7, wherein the first multi-link device further includes a transceiver unit configured to receive the first value, the first value being carried in a beacon frame, an association response frame, or a reassociation response frame.

9. The first multi-link device according to claim 6 or 7, wherein the processing unit is further configured to: determine an initial value of the media synchronization delay timer, which corresponds to the length of the first PPDU, when the length of the first PPDU is greater than the first value, and to start the media synchronization delay timer with respect to the second link using the initial value.

10. The first multi-link device according to claim 9, wherein the first multi-link device further includes a transceiver unit, the transceiver unit is configured to receive first instruction information, the first instruction information is used to indicate a mapping relationship between the PPDU length and the initial value of the media synchronization delay timer.

11. A first multi-link device including a processor, wherein the processor is configured to: skip starting a media synchronization delay timer with respect to a second link when the length of a first PPDU transmitted by the first multi-link device over a first link is less than or equal to a first value, and set an energy detection threshold used by a clear channel evaluation (CCA) performed with respect to the second link to -62 dB.

12. A first multi-link device comprising an input / output interface and a processing circuit, wherein the input / output interface is configured to receive a code instruction and transmit the code instruction to the processing circuit; and the processing circuit is configured to: skip starting a medium synchronization delay timer with respect to a second link when the length of a first PPDU transmitted on the first link is less than or equal to a first value, and set an energy detection threshold used by a clear channel evaluation (CCA) performed on the second link to -62 dB.

13. A computer-readable storage medium, the computer-readable storage medium storing program instructions, and when the program instructions are executed on a computer, the computer is able to perform the method according to claim 1.

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