Channel access method for multi-link device and related device

Abstract

To provide a channel access method for a multi-link device and a related apparatus, being applied to a wireless local area network.SOLUTION: The method includes: when a length of a first PPDU transmitted on a first link by a first multi-link device is less than or equal to a first value, skipping starting, by the first multi-link device, a medium synchronization delay timer on a second link. The first multi-link device is not allowed to perform simultaneous transmitting and receiving on the first link and the second link. The method can improve channel access efficiency when a non-simultaneous transmitting and receiving multi-link device (non-STR MLD) is in a blind state / self-interference state.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001]

[0001] This application claims priority to Chinese Patent Application No. 202010924423.8, entitled "Channel Access Method and Related Apparatus for Multi-Link Device," filed with the State Intellectual Property Office of the People's Republic of China on September 4, 2020, the entire contents of which are incorporated herein by reference.

[0002]

[0002] Technical field The present application relates to the field of wireless communication technology, and in particular to a channel access method and related apparatus for a multi-link device. [Background technology]

[0003]

[0003] As wireless communication technology develops, an increasing number of wireless communication devices support multi-link communication, for example, simultaneous communication in the 2.4 GHz, 5 GHz, and 6 GHz frequency bands, or simultaneous communication in different channels of the same frequency band. This type of wireless communication device is usually called 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] A multi-link device can perform parallel communication by using multiple links to increase the transmission rate. However, when the frequency spacing between 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, an EHT multi-link device performs transmission on Link 1. Because the frequency spacing between Link 1 and Link 2 is small, signal transmission on Link 1 causes channel interference for Link 2, affecting channel access and information reception on Link 2. Therefore, to avoid mutual interference, devices are not allowed to independently perform simultaneous transmission and reception on multiple frequency bands. According to the current progress of the IEEE 802.11 TGbe standardization group, it is specified that an EHT multi-link device may have simultaneous transmitting and receiving (STR) capabilities and non-simultaneous transmitting and receiving (non-STR) capabilities.

[0005]

[0005] When an MLD with non-STR capability (referred to as non-STR MLD for short) transmits on a link, the non-STR MLD is in a blind state (referred to as a blind period or deafening period) because interference affects the clear channel assessment (CCA) performed on another link. A blind state means that the non-STR MLD cannot hear any information on the channel or fails to hear any information on the channel. Therefore, if the non-STR MLD is in a blind state on some links, how the non-STR MLD performs channel access on these links becomes an urgent problem to be solved. Summary of the Invention

[0006]

[0006] The embodiments of the present application provide a channel access method and related apparatus for a multi-link device, which improves channel access efficiency when a non-STR MLD is in a blind state / self-interference state.

[0007]

[0007] The present application will now be described from various aspects, and it should be understood that cross-reference may be made to the implementations and beneficial effects of the various aspects below.

[0008]

[0008] According to a first aspect, the present application provides a channel access method for a multi-link device, the method including: if the length of a first PPDU transmitted by the first multi-link device on a first link is less than or equal to a first value, the first multi-link device does not start a medium synchronization delay timer for a second link; and the first multi-link device is not allowed to perform simultaneous transmission and reception on the first link and the second link.

[0009]

[0009] The first multi-link device not starting the media synchronization delay timer for the second link includes: when performing channel contention for the second link, the first link device sets the energy detection threshold used by the clear channel assessment CCA performed for the second link to a first threshold, wherein 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 RTS frames and MU-RTS frames.

[0010]

[0010] In this solution, if the length of a PPDU transmitted on one link is equal to or less than a certain value, the medium synchronization delay timer is not started for another link; or if channel contention is performed on another link, the energy detection threshold used in CCA is set to -62 dBm; or there is no need to use an RTS frame on another link to attempt to detect channel protection / availability, thereby improving the channel access efficiency or channel access success rate of the first multi-link device on the other link, or increasing the channel access opportunities of the first multi-link device on the other link.

[0011]

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

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

[0013]

[0013] Regarding the first aspect, in a possible implementation, the method further includes: when the length of the first PPDU is greater than the first value, the first multi-link device determining an initial value of a media synchronization delay timer, the initial value corresponding to the length of the first PPDU, and starting the media synchronization delay timer using the initial value for the second link.

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

[0016]

[0016] With regard to the first aspect, in a possible implementation, the method further includes: a step in which the first multi-link device starts a second synchronization delay timer for the second link when the length of the first PPDU is greater than a first value; and a step in which, if the first multi-link device is performing channel contention for the second link within the period in which the media synchronization delay timer is running, the first multi-link device sets the energy detection threshold used by the CCA performed for the second link to a threshold corresponding to the length of the first PPDU.

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

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

[0019]

[0019] According to a second 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 first multi-link device includes a processing unit. The processing unit is configured to skip starting a medium synchronization delay timer for a second link when the length of a first PPDU transmitted by the first multi-link device on the first link is less than or equal to a first value. The first multi-link device is not allowed to perform simultaneous transmission and reception on the first link and the second link.

[0020]

[0020] The processing unit is specifically configured to set an energy detection threshold used by the clear channel assessment (CCA) performed for 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 a back-off counter for the second link backs off to 0.

[0021]

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

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

[0023]

[0023] Regarding the second aspect, in a possible implementation, the processing unit is further configured to: when the length of the first PPDU is greater than the first length, determine an initial value of the media synchronization delay timer, the initial value corresponding to the length of the first PPDU, and start the media synchronization delay timer using the initial value for the second link.

[0024]

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

[0025]

[0025] Regarding the second aspect, in a possible implementation, the processing unit is further configured to: start a synchronization delay timer for the second link when the length of the first PPDU is greater than a first value; and if the first multi-link device is performing channel contention for the second link during the period in which the media synchronization delay timer is running, set the energy detection threshold used by the CCA performed for 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, wherein the transceiver unit is further configured to receive second indication information, wherein the second indication information is used to specify a mapping relationship between a length of the PPDU and an energy detection threshold.

[0027]

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

[0028]

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

[0029] Optionally, the first frame is a frame: Request to send (RTS) frame, Multi-user Request-to-Send (MU-RTS) frame, Power save pole (PS-Poll) frame, Clear-to-Send CTS Frame, Status report (buffer status report, BSR) frame, Bandwidth Query Report (BQR) frame, Null data packet (NDP) frame, Acknowledgement (ACK) frames, and Block Acknowledge (Block ACK, BA) Frame The type of the first frame is the first type if either of

[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 on the first link within a predetermined period, the first multi-link device does not start a medium synchronization delay timer on the second link.

[0031] Optionally, the first frame is a Power Save Poll (PS-Poll) frame. If the first multi-link device does not receive a data frame or an acknowledgement frame on the first link within a predetermined period, the first multi-link device does not start a medium synchronization delay timer on the second link.

[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] 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 poll (BSRP) trigger frame on the first link.

[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 (BQRP) trigger frame on the first link.

[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: receiving, by the first multi-link device, a beamforming report poll (BFRP) trigger frame on the first link.

[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 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 first multi-link device includes a processing unit. The processing unit is configured to skip starting a medium synchronization delay timer for a second link when a type of a first frame transmitted by the first multi-link device on the first link is a first type. The first multi-link device is not allowed to perform simultaneous transmission and reception on the first link and the second link.

[0038]

[0038] The processing unit is specifically configured to set an energy detection threshold used by the clear channel assessment (CCA) performed for 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 a back-off counter for the second link backs off to 0.

[0039] Optionally, the first frame is a frame: Request to send (RTS) frame, Multi-user Request-to-Send (MU-RTS) frame, 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, Acknowledgement (ACK) frames, and Block Acknowledge (Block ACK, BA) Frame The type of the first frame is the first type if either of

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

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

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

[0044] Optionally, the first PPDU is a Bandwidth Query Report (BQR) frame. The first multi-link device further includes a transceiver unit configured to receive a Bandwidth Query Report (BQRP) trigger frame 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 configured to receive a Beamforming Report Polling (BFRP) trigger frame over 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. The transceiver unit is configured to receive a data frame or a management frame on the first link.

[0047]

[0047] According to a fifth aspect, the present application provides a method for determining an initial period of a media synchronization delay timer. The method includes: a first multi-link device receiving first indication information, the first indication information being used to indicate a mapping relationship between the length of a PPDU and an 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, the initial value corresponding to the length of the first PPDU, based on the length of the first PPDU transmitted on the first link, and the initial value is used to determine whether to start a media synchronization delay timer for a second link. The first multi-link device is not allowed to perform simultaneous transmission and reception on the first link and the second link.

[0048]

[0048] Optionally, the first multi-link device determines whether to start a media synchronization delay timer for the second link based on an initial value of the media synchronization delay timer, the initial value corresponding to the length of the first PPDU.

[0049] Optionally, if the determined initial value 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. If the determined initial value of the media synchronization delay timer is equal to 0, the first multi-link device starts the media synchronization delay timer with the initial value for the second link.

[0050] The possibility that the first multi-link device starts the mediumSyncDelay timer for the second link may be understood (or described) as the possibility that the first multi-link device may use a more conservative channel access mechanism for the second link during the period in which the mediumSyncDelay timer is running. The 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) requiring the transmission of an RTS frame to attempt to detect channel availability.

[0051]

[0051] In this solution, different PPDU lengths / byte lengths correspond to different initial values ​​of the mediumSyncDelay timer, allowing for more flexible configuration of the mediumSyncDelay timer and improving channel access efficiency.

[0052]

[0052] According to a sixth aspect, the present application provides a method for determining an initial period of a media synchronization delay timer. The method includes: a second multi-link device generating and transmitting first indication information. The first indication information is used to indicate a mapping relationship between a PPDU length and an 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 indication information, the first indication information being used to indicate a mapping relationship between a PPDU length and an initial value of a media synchronization delay timer; and a processing unit configured to determine an initial value of a media synchronization delay timer based on the length of the first PPDU transmitted on the first link, the initial value corresponding to the length of the first PPDU. The communication device is not allowed to transmit and receive simultaneously on the first link and the second link.

[0054]

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

[0055]

[0055] Optionally, the processing unit is configured specifically 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 to 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 in the second multi-link device, for example, a Wi-Fi chip. The second multi-link device may be a STR MLD. A communication device includes: a processing unit configured to generate first indication information, the first indication information being used to indicate a mapping relationship between a PPDU length and an initial value (or initial period) of a medium synchronization delay timer; and a transceiver unit configured to transmit the first indication information.

[0057]

[0057] According to a ninth aspect, the present application provides a method for determining an energy detection threshold in a CCA process. The method includes: a first multi-link device receiving second indication information, where the second indication information is used to indicate a mapping relationship between a PPDU length and an energy detection threshold; the first multi-link device transmits a first PPDU on a first link; 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 on the first link, where the energy detection threshold is used to determine whether to start a medium synchronization delay timer for the second link; and the first multi-link device is not allowed to transmit and receive on the first link and the second link simultaneously.

[0058]

[0058] Optionally, the first multi-link device determines whether to start a media 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 a media 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 a media synchronization delay timer for the second link.

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

[0061] According to a tenth aspect, the present application provides a method for determining an energy detection threshold in a CCA process, the method including: a second multi-link device generating and transmitting second indication information, the second indication information being used to indicate a mapping relationship between a PPDU length and an 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, such as 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 second indication information, the second indication information being used to indicate a mapping relationship between a PPDU length and an energy detection threshold; and a processing unit configured to determine an energy detection threshold corresponding to the length of the first PPDU transmitted on the first link, based on the length of the first PPDU, the energy detection threshold being used to determine whether to start a medium synchronization delay timer for the second link. The first multi-link device is not allowed to transmit and receive simultaneously on the first link and the second link.

[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 a length of the first PPDU, and the communication device is not allowed to transmit and receive on the first link and the second link simultaneously.

[0064]

[0064] Optionally, the processing unit is configured to, specifically: skip starting a media synchronization delay timer for the second link if the determined energy detection threshold is equal to -62 dBm; or start a 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 in the second multi-link device, for example, a Wi-Fi chip. The second multi-link device may be a STR MLD. A communication device includes: a processing unit configured to generate second indication information, the second indication information being used to indicate a mapping relationship between a PPDU length and an energy detection threshold; and a transceiver unit configured to transmit the second indication information.

[0066] According to a thirteenth aspect, the present application 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 a second link if the length of a first PPDU transmitted by the first multi-link device on the first link 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 link and the second link.

[0067] In one possible design, the processor is configured to: skip starting a medium synchronization delay timer for the second link if a type of a first frame transmitted by the first multi-link device on the first link is a first type, and the first multi-link device is not allowed to perform simultaneous transmission and reception on the first link and the second link.

[0068]

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

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

[0070]

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

[0071]

[0071] In a possible 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.

[0072]

[0072] According to a fifteenth aspect, the present application provides a first multi-link device. The first multi-link device may exist in the form of a chip product. The structure of the first 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: skip starting a medium synchronization delay timer for 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 allowed to perform simultaneous transmission and reception for the first link and the second link.

[0073] In one possible design, the input / output interface is configured to receive code instructions and transmit the code instructions to a processing circuit configured to: skip starting a medium synchronization delay timer for a second link if a type of a first frame transmitted by the first multi-link device on the first link is a first type; and the first multi-link device is not allowed to perform simultaneous transmission and reception on the first link and the second link.

[0074]

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

[0075]

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

[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 product. 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 a code instruction and transmit the code instruction to the processing circuit. The processing circuit is configured to generate first indication information, which is used to indicate a mapping relationship between a PPDU length and an initial value (or initial period) of a media synchronization delay timer. The input / output interface is configured to transmit the first indication information to a transceiver. The transceiver is configured to transmit the first indication information.

[0077]

[0077] In a possible implementation, 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 second instruction information, wherein the second instruction information 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 the transceiver; and the transceiver is configured to transmit the second instruction information.

[0078] According to a seventeenth aspect, the present application provides a computer-readable storage medium having stored thereon instructions that, when executed by a computer, enable the computer to perform a method according to the first, third, fifth, seventh, ninth or tenth aspect.

[0079] According to an eighteenth aspect, the present application provides a computer program product comprising program instructions which, when executed on a computer, enable the computer to perform a method according to the first, third, fifth, seventh, ninth or tenth aspect.

[0080]

[0080] When the embodiments of the present application are implemented, channel access efficiency can be improved when non-STR MLD is in a blind state / self-interference state. [Brief explanation of the drawings]

[0081]

[0081] In order to more clearly explain the technical solutions in the embodiments of the present invention, the following briefly describes the accompanying drawings for explaining the embodiments. [Figure 1]

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

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

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

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

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

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

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

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

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

[0091] FIG. 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 application. [Figure 8]

[0092] FIG. 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 application. [Figure 9]

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

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

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

[0096] FIG. 12 is a schematic diagram of the structure of a second multi-link device according to an embodiment of the present application. DETAILED DESCRIPTION OF THE INVENTION

[0082]

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

[0083]

[0098] To facilitate understanding of the channel access method for a multi-link device provided in the embodiments of the present application, the following describes the system architecture and / or application scenario of the channel access method for a multi-link device provided in the embodiments of the present application. It will be understood that the system architecture and / or scenario described in the embodiments of the present application are intended to more clearly describe the technical solutions in the embodiments of the present application, and do not constitute limitations on the technical solutions provided in the embodiments of the present application.

[0084]

[0099] An embodiment of the present application provides a channel access method applicable to non-STR MLD. Using this method can improve channel access efficiency when non-STR MLD is in a blind state / self-interference state. The channel access method for a multi-link device can be implemented by a communication device of 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 over multiple links. For example, the communication device may be referred to as a multi-link device or a multi-band device. Compared with 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). A affiliated station is a logical station operating on a link, frequency band, or channel. A affiliated station may be an access point (AP) or a non-access point station (non-AP STA). For ease of explanation, a multi-link device whose affiliated station is an AP will be referred to herein as a multi-link AP, multi-link AP device, or AP multi-link device (AP MLD), and a multi-link device whose affiliated station is a non-AP STA will be referred to herein as a multi-link non-AP, multi-link non-AP device, or non-AP multi-link device (non-AP MLD).

[0086]

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

[0087]

[0102] Optionally, one or more STAs in the non-AP MLD may establish an association relationship with one or more APs in the AP MLD and then perform communication. Figure 1 is a schematic diagram of communication between the non-AP MLD and the AP MLD according to an embodiment of the present application. 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 Link 1, Link 2, ..., Link n. STA1 in the non-AP MLD establishes an association relationship with AP1 in the AP MLD; STA2 in the non-AP MLD establishes an association relationship with AP2 in the AP MLD; STA3 in the non-AP MLD establishes an association relationship with AP3 in the AP MLD; and so on.

[0088]

[0103] Optionally, a multi-link device may be compliant with the IEEE 802.11 series of protocols to conduct wireless communications, such as an extremely high throughput (EHT) compliant station or a station that is compliant with or capable of supporting IEEE 802.11 be to conduct communications with another device.

[0089]

[0104] The channel access method for a multi-link device 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 may be applied to a single-user uplink / downlink communication scenario or a multi-user uplink / downlink communication scenario, or may be applied 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, a scenario where an AP MLD communicates with an AP MLD, or a scenario where a non-AP MLD communicates with a non-AP MLD, which is not limited in the embodiments of the present application.

[0091]

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

[0092]

[0107] Optionally, for ease of explanation, the system architecture of the present application 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 a multi-link device provided in an embodiment of the present application may be applied to a wireless local area network (WLAN). FIG. 2 is a schematic diagram of a wireless communication system architecture according to an embodiment of the present application. As shown in FIG. 2, the wireless communication system includes at least one AP MLD and at least one non-AP MLD. The AP MLD is a multi-link 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 numbers of AP MLDs and non-AP MLDs in FIG. 2 are merely examples. Optionally, the wireless communication system includes at least one MLD capable of non-STR.

[0093]

[0108] For example, a multi-link device (here, either a non-AP MLD or an AP MLD) is a device with wireless communication capabilities. The device may be an integrated device, or may be a chip or a processing system mounted on an integrated device. A device mounted with a chip or a processing system can implement the methods and functions provided in the embodiments of the present application under the control of the chip or processing system. For example, a non-AP multi-link device in the embodiments of the present application may have wireless transceiver capabilities, support 802.11 series protocols, and 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 allows 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. Alternatively, it may be an Internet of Things node in the Internet of Things or an in-vehicle communication device in the Internet of Vehicles. Alternatively, a non-AP multi-link device may be the chip and processing system in the above terminal. An AP multi-link device may be a device that provides services to non-AP multi-link devices 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, the 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 802.11be or is compatible with 802.11be.

[0094]

[0109] It can be understood that multi-link devices may support high-speed, low-latency transmission. With the continuous advancement of application scenarios for wireless local area networks, multi-link devices may be applied to more scenarios, such as sensor nodes in smart cities (e.g., smart meters, smart electricity meters, and smart air detection nodes), smart home devices (e.g., smart cameras, projectors, displays, televisions, stereos, refrigerators, and washing machines), Internet of Things nodes, entertainment terminals (e.g., wearable devices such as AR and VR), smart office devices (e.g., printers and projectors), Internet of Vehicles devices, and some infrastructures in daily life scenarios (e.g., vending machines, supermarket self-service navigation stations, self-service register devices, and self-service ordering machines). The specific form of the multi-link device is not limited to this embodiment of the present application and is provided herein for illustrative purposes only.

[0095]

[0110] Optionally, FIG. 3a is a schematic diagram of a multi-link device structure according to an embodiment of the present application. 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 FIG. 3a, multiple STAs included in a multi-link device are independent of each other at the low MAC layer and the PHY layer, and also independent of each other at the high MAC layer. FIG. 3b is a schematic diagram of another multi-link device structure according to an embodiment of the present application. As shown in FIG. 3b, multiple STAs included in a multi-link device are independent of each other at the low MAC layer and the PHY layer, and share a high MAC layer. Of course, non-AP multi-link devices may use a structure in which the high MAC layers are 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 layer is shared, or a structure in which the high MAC layers are independent of each other. The schematic diagram of the internal structure of the multi-link device is not limited to the embodiments of the present application. Figures 3a and 3b are merely examples for explanation. For example, the high MAC layer and the low MAC layer may be implemented by one processor in the chip system of the multi-link device, or may be implemented by different processing modules in the chip system.

[0096]

[0111] For example, a multi-link device in an embodiment of the present application may be a single-antenna device or a multi-antenna device, e.g., a device having two or more antennas. The number of antennas included in a multi-link device is not limited in the embodiments of the present application. In an embodiment of the present application, a 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 packet to be transmitted over different links; or alternatively, it may not allow services of the same access class to be transmitted over different links, but may allow services of different access classes to be transmitted over different links.

[0097]

[0112] The frequency bands in which a multi-link device operates 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 status of the channel on another link or multiple links (e.g., link 2 is used), affecting the reception of overlapped basic service set (OBSS) frames on link 2 by the non-STR MLD. OBSS frames are used by stations to update their network allocation vectors (NAV). Therefore, before a transmission performed on a link is completed, the non-STR MLD may miss an OBSS frame on another link and thus miss a NAV update. In this case, if a non-STR MLD contends for the channel on link 2 and accesses the channel after the transmission performed on link 1 is completed, the data transmitted on link 2 will collide with the received OBSS frame. This is known as the blind problem or self-interference problem.

[0099]

[0114] It will be understood that NAV can be understood as a countdown timer, gradually decreasing as time passes. When NAV is 0, the medium is considered to be idle. Specifically, after a station receives a frame, if the receiving address of the frame is not the station, the station can update its NAV based on the duration field of the received frame. If the receiving address of the frame is the station, it indicates that the station is the receiving station. In this case, the station is not allowed to update its NAV. Before updating its NAV, the station can 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 is completed is used for comparison.

[0100]

[0115] To solve the blinding problem of non-STR MLD, an embodiment of the present application proposes a medium synchronization delay (mediumSyncDelay) mechanism. Specifically, this mechanism is as follows: after transmitting on a link (e.g., link 1), the non-STR MLD needs to start a timer for another link, i.e., the mediumSyncDelay timer. During the period indicated by the mediumSyncDelay timer, the non-STR MLD needs to use a more conservative channel access mechanism for link 2. More conservative channel access mechanisms include, but are not limited to, the following: (1) Whether a channel is busy is determined by using a low energy detection (ED) threshold. In the channel access mechanism, -62 dBm is typically used as the energy detection threshold. If the energy on the 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 signal further away will make the channel busy in CCA detection. Therefore, the channel access is more conservative. The low energy detection threshold may be -82 dBm, -72 dBm, etc. (2) An attempt to detect channel availability requires that a request to send (RTS) frame be transmitted. Optionally, this can be a one-time attempt (or one-time transmission of an RTS frame) or a limited number of attempts.

[0101]

[0116] In the medium synchronization delay mechanism, as long as a non-STR MLD is transmitting on link 1, the non-STR MLD uses a more conservative channel access mechanism for 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 the data frames can be long or short frames. Therefore, when a non-STR MLD transmits a short frame on link 1, the non-STR MLD is correspondingly blinded on link 2 for a short period of time, and the possibility (or probability) that the non-STR MLD misses important information (e.g., NAV) regarding link 2 is low. In conclusion, the medium synchronization delay mechanism requires that as long as a non-STR MLD is transmitting on link 1, the 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 fewer channel access opportunities on link 2.

[0102]

[0117] In this application, "a non-STR MLD is blinded on a link" may alternatively be understood as a STA in a non-STR MLD operating on the link being blinded.

[0103]

[0118] It will be understood that the "blind state" referred to in this application may also be referred to as a "self-interference state," a "no reception state," a "cannot hear state," or the like.

[0104]

[0119] It will be understood that a "non-STR MLD" in this application may be an EHT MLD that is not allowed to perform simultaneous transmission and reception.

[0105]

[0120] It will be understood that "long frames" and "short frames" referred to herein are distinguished from one another by the length of time the frames occupy the air interface. For example, a "long frame" may be a frame that occupies the air interface for a duration equal to or greater than a predetermined value A, and a "short frame" may be a frame that occupies the air interface for a duration equal to or less than a predetermined value B. The predetermined value A and the predetermined value 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] An embodiment of the present application provides a channel access method for a multi-link device, which improves the channel access efficiency or channel access success rate of a non-STR MLD on some links, or increases the channel access opportunities of a non-STR MLD on these links when the non-STR MLD is in a blind state / self-interference state on these links.

[0107]

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

[0108]

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

[0109]

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

[0110]

[0125] Hereinafter, Embodiments 1 to 4 will be described in detail individually. It should be understood that the technical solutions described in Embodiments 1 to 4 of the present application may be arbitrarily combined to form new embodiments.

[0111]

[0126] Embodiment 1 In embodiment 1 of the present application, a method is described for determining whether a more conservative channel access mechanism needs to be used on one link based on the type of frame transmitted on another link.

[0112]

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

[0113]

[0128] S101: When the type of a first frame transmitted by a first multi-link device on a first link is a first type, the first multi-link device does not start a medium synchronization delay timer for a second link, and wherein the first multi-link device is not allowed to perform simultaneous transmission and reception on the first link and the second link.

[0114]

[0129] A first frame is of a first type if it is one of the following frames: a request to send (RTS) frame, a multiple user request to send (MU-RTS) frame, a power save-poll (PS-Poll) frame, a clear to send (CTS) frame, a buffer status report (BSR) frame, a bandwidth query report (BQR) frame, a null data packet (NDP) frame, an acknowledge (ACK) frame, and a block ACK (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 preset period, the first multi-link device does not start the medium synchronization delay timer for the second link. The first multi-link device is not allowed to transmit and receive simultaneously on 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 length of the short inter-frame space (SIFS), the length of one slot, and the sum of 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 does 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 for 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 detection threshold used by the CCA operation is the first threshold; alternatively, after the back-off counter for the second link backs off to 0, the first multi-link device is allowed to immediately transmit frames other than RTS and MU-RTS frames. In other words, after the back-off counter for the second link backs off to 0, the first multi-link device does not transmit RTS / MU-RTS frames to 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 preset period (e.g., SIFS Time+Slot Time+RxPHYStartDelay) may be: (a) the RTS frame transmitted by the first multi-link device collides 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, the first multi-link device starts a mediumSyncDelay timer for the second link after transmitting an RTS / MU-RTS frame on the first link, and if the first multi-link device does not receive a CTS frame within a preset 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 preset period, the first multi-link device can start the mediumSyncDelay timer. The fact that the first multi-link device starts the mediumSyncDelay timer for the second link may be understood (or stated) as follows: the first multi-link device uses a more conservative channel access mechanism for the second link. Specifically, to determine whether the channel is busy, a low energy detection threshold (which is an energy detection threshold lower than -62 dBm, e.g., -82 dBm) is used, and an RTS / MU-RTS frame must be transmitted to attempt to detect channel availability. Optionally, this can be a one-time attempt (or one 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 acknowledgement (ACK) frame. Therefore, the first implementation may alternatively be 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 an acknowledgement frame within a preset period, the first multi-link device does not start the medium synchronization 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 an acknowledgement frame within a preset period, the first multi-link device may start the mediumSyncDelay timer.

[0121]

[0136] In this embodiment of the present application, if a non-STR MLD (i.e., the first multi-link device) 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 for the second link, and as a result, the non-STR MLD can know to perform co-channel contention for the second link, i.e., that the energy detection threshold used in CCA operation is −62 dBm, or that the RTS / CTS frame may not be used to attempt to detect channel protection. Therefore, the channel access efficiency or channel access success rate of the non-STR MLD for the second link is improved, or the channel access opportunities of the non-STR MLD for the second link are increased.

[0122]

[0137] In the second implementation, the first frame is a CTS frame. Specifically, when the first multi-link device receives an RTS frame or MU-RTS frame on the first link and responds with a CTS frame / transmits a CTS frame on the first link, the first multi-link device does not start the medium synchronization delay timer (mediumSyncDelay timer) on the second link. The first multi-link device is not allowed to transmit and 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. In response, the first multi-link device receives an RTS frame or MU-RTS frame on the first link and responds with a CTS frame / transmits a CTS frame on the first link. After transmitting the CTS frame on the first link, the first multi-link device does not start the mediumSyncDelay timer on the second link.

[0123]

[0138] The fact that the first multi-link device does not start the mediumSyncDelay timer for 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 detection threshold used by the CCA operation is the first threshold; or, after the back-off counter for the second link backs off to 0, the first multi-link device is allowed to immediately transmit frames other than RTS and MU-RTS frames. In other words, after the back-off counter for the second link backs off to 0, the first multi-link device does not transmit RTS / MU-RTS frames to attempt to detect channel protection / availability. The first threshold may be -62 dBm.

[0124]

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

[0125]

[0144] Optionally, the "RTS / CTS frame" in the second implementation may be replaced by 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 / acknowledge (ACK) frame, a management frame / ACK frame, or a data frame / block acknowledge (BA) frame. Therefore, step S201 may alternatively be stated as follows: the first multi-link device receives a BSRP trigger frame on the first link and responds with a BSR frame / transmits a BSR frame on the first link; or the first multi-link device receives a BFRP trigger frame on the first link and responds with a BQR frame / transmits a BQR frame on the first link; or the first multi-link device receives a BFRP trigger frame on the first link and responds with an NDP frame / transmits an NDP frame on the first link; or the first multi-link device receives a data frame or management frame on the first link and responds with an ACK frame / transmits an ACK frame on the first link; or the first multi-link device receives a data frame on the first link and responds with a BA frame / transmits a BA frame on the first link.Correspondingly, the second implementation may alternatively be stated as follows: after transmitting a BSR frame, a BQR frame, or an NDP frame on the first link, the first multi-link device does not start a media synchronization delay timer for the second link.

[0126]

[0144] After responding with / transmitting a CTS frame, an NDP frame, a BSR frame, a BQR frame, an ACK frame, or a BA frame on the first link, it can be understood 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 co-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] It can be known that after a non-STR MLD (i.e., a first multi-link device) in this embodiment of the present application receives an RTS (or MU-RTS) frame on a first link and responds with a CTS frame, the non-STR MLD does not start the mediumSyncDelay timer for the second link, which can improve the channel access efficiency or channel access success rate of the non-STR MLD for the second link, or increase the channel access opportunities of the non-STR MLD for the second link.

[0128]

[0143] In this embodiment of the present application, when a frame of a certain type is transmitted on a first link, the medium synchronization delay timer is not started for a second link, so that when a non-STR MLD is in a blind state / self-interference state on some links, the channel access efficiency or channel access success rate of the non-STR MLD on these links can be improved, or the channel access opportunities of the non-STR MLD on these links can be increased.

[0129]

[0144] Embodiment 2 In embodiment 2 of the present application, a method for a non-STR MLD to perform channel access on a second link when the length of a PPDU transmitted on a first link is less than a preset value is described.

[0130]

[0145] 5 is another schematic flowchart of a channel access method for a multi-link device according to an embodiment of the present application. As shown in FIG. 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 a first PPDU transmitted by a first multi-link device on a first link is less than or equal to a first value, the first multi-link device does not start a medium synchronization delay timer for a second link, wherein the first multi-link device is not allowed to transmit and receive simultaneously on the first link and the second link.

[0132]

[0147] The fact that the first multi-link device does not start the medium synchronization delay timer for the second link may be understood (or stated) as follows: when the first multi-link device performs channel contention for 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 backs off to 0, the first multi-link device is allowed to immediately transmit frames other than RTS and MU-RTS frames. In other words, after the back-off counter for the second link backs off to 0, the first multi-link device does not transmit RTS / MU-RTS frames to attempt to detect channel protection / availability. The first threshold may be -62 dBm.

[0133]

[0148] Optionally, if the first multi-link device starts a mediumSyncDelay timer for the second link after transmitting the first PPDU on the first link, the first multi-link device closes (or stops or cancels) the mediumSyncDelay timer when it determines that the length of the first PPDU is less than or equal to the first value.

[0134]

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

[0135]

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

[0136]

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

[0137]

[0152] Optionally, the first value may be 28 μs, which 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 32 μs, which is the PPDU length present when a block acknowledge (BA) frame with a bitmap length of 64 is transmitted in a 24 Mbps non-HT PPDU or 24 Mbps non-HT double PPDU format.

[0139]

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

[0140]

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

[0141]

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

[0142]

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

[0143]

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

[0144]

[0159] In implementation, the indication information may be placed in a multi-link element. FIG. 6A is a schematic diagram of a frame structure of a multi-link element according to an embodiment of the present application. As shown in FIG. 6A, the 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 field, etc. The medium sync delay timer threshold field is used to indicate a first value.

[0145]

[0160] In another implementation, the indication information may be placed in an EHT operation element. Fig. 6b is a schematic diagram of a frame structure of an EHT operation element according to an embodiment of the present application. As shown in Fig. 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, etc. The medium sync delay timer threshold field is used to indicate a first value.

[0146]

[0161] In yet another implementation, a new information element may alternatively be defined to transmit the indication 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 another name. This is not limited to this embodiment of the present application. Figure 6c is a schematic diagram of a frame structure of a non-STR MLD parameter set element according to an embodiment of the present 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 start a media synchronization delay timer for the second link. While the media synchronization delay timer is running, the first multi-link device may use a more conservative channel access mechanism for 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) transmitting an RTS frame to attempt to detect channel availability. Optionally, there may be only one attempt (or only one 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 to be either not starting a media synchronization delay timer for the second link or starting a media synchronization delay timer for the second link. In the embodiment of the present application, when the length of the first PPDU is equal to the first value, the operation performed by the first multi-link device may be set based on the actual situation.

[0148]

[0163] Optionally, before starting the media synchronization delay timer for the second link, the first multi-link device may determine an initial value of the media synchronization delay timer, the initial value corresponding to the length of the first PPDU. It will be understood that the initial value of the media synchronization delay timer started 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 PPDU length and the initial value (or initial period) of the media synchronization delay timer may be specified in a standard protocol. Alternatively, before the first multi-link device transmits the first PPDU on the first link, the second multi-link device transmits first indication information. In response, the first multi-link device receives the first indication information. The first indication 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 of starting the medium synchronization delay timer for the second link, the first multi-link device determines an energy detection threshold corresponding to the length of the first PPDU, and when performing channel contention on the second link, the first multi-link device sets the energy detection threshold used in CCA operations to the threshold corresponding to the length of the first PPDU.

[0151]

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

[0152]

[0167] It will be understood that the first indication information and the second indication information may be part of the indication information, i.e., the part of the indication information indicates both the mapping relationship between the length of the PPDU and the initial value (or initial period) of the medium synchronization delay timer and the mapping relationship between the length of the PPDU and the energy detection threshold. In other words, the first indication information and the second indication information are carried within a frame.

[0153]

[0168] In this embodiment of the present application, after transmitting a short frame on one link, the non-STR MLD for another link is restricted from starting the mediumSyncDelay timer; or, when channel contention is performed on another link, the energy detection threshold used in CCA is set to -62 dBm; or, it can be known that there is no need to use an RTS frame on another link to attempt to detect channel protection / availability. Therefore, the channel access efficiency or channel access success rate of the non-STR MLD for another link is improved, and the channel access opportunities of the non-STR MLD for another link are increased.

[0154]

[0169] In an optional embodiment, the “length of the first PPDU” may be replaced with “length of a 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 by the first multi-link device on the first link is less than or equal to the second value, the first multi-link device does not start the medium synchronization delay timer for the second link, and wherein the first multi-link device is not allowed to transmit and receive on the first link and the second link simultaneously.

[0155]

[0170] In another optional embodiment, the channel access methods 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 an AP can use two channels for channel access, but can only complete access on one channel at a time and cannot access two channels simultaneously. Specifically, the AP performs channel contention on a primary channel, e.g., the first channel. If the primary channel is busy, the AP can switch to another channel (e.g., 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] For 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, a CTS frame, a block acknowledge (BA) frame, a BSR frame, a BQR frame, a PS-Poll frame, or an NDP frame) on the second channel, the AP does not start a timer for the first channel. The timer may be a media 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 media synchronization delay timer for the first channel.

[0157]

[0172] Optionally, the AP not starting 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 backs off to 0, the AP is allowed to immediately transmit frames other than RTS and MU-RTS frames. In other words, after the back-off counter for the first channel backs 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 scenario of the method and improving the channel access success rate or channel access efficiency of the AP for the first channel.

[0160]

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

[0161]

[0176] 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 application. As shown in FIG. 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 indication information, where the first indication information is used to indicate a mapping relationship between a PPDU length / byte length and an initial value (or initial period) of a media synchronization delay timer.

[0163]

[0178] Specifically, the second multi-link device may be an AP MLD, and the AP MLD has STR capability. The AP MLD may transmit first indication information on the first link or another link. This is not limited to this embodiment of the present application. The first indication 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] 8 is a schematic diagram of a mapping relationship between the PPDU length and the initial value of the media synchronization delay timer according to an embodiment of the present application. As shown in FIG. 8, when the PPDU length is within the range of 0 to 100 μs (microseconds) (i.e., the interval [0,100 μs], the interval (0,100 μs), the interval (0,100 μs), or the 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., the interval [100,1000 μs], the interval (100,1000 μs), the interval (100,1000 μs), or the interval [100,1000 μs]), the initial value of the media synchronization delay timer is 3 ms; and when the PPDU length is equal to or greater than 1 ms, the initial value of the media synchronization delay timer is 6 ms.

[0165]

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

[0166] [Table 1]

[0181] It should be understood that the mapping relationship shown in Figure 8 and Table 1 is merely an example, and that in a real application, the mapping relationship can be determined based on the actual application scenario. For example, the mapping relationship may alternatively be as follows: if the PPDU length is 50 μs or less, the initial value of the media synchronization delay timer is 0 ms; if 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; if 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 if 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 indication information may include an array. For example, the array (0,100,0) indicates that the initial value of the media synchronization delay timer is 0 ms when the PPDU length is within the range of 0 to 100 μs; the array (100,1000,3) indicates that the initial value of the media synchronization delay timer is 3 ms when the PPDU length is within the range of 100 μs to 1 ms; and the array (1000,maximum PPDU length,6) indicates that the initial value of the media synchronization delay timer is 6 ms when the PPDU length is within the range of 1 ms to the maximum PPDU length. The maximum PPDU length is specified in the standard protocol.

[0168]

[0183] Optionally, the first indication information may include two fields: a first field is used to determine the N intervals, and a second field is used to indicate initial values ​​of the media synchronization delay timers corresponding to each of the N intervals.

[0169]

[0184] The first field may include N+1 subfields. The values ​​of the N+1 subfields increase monotonically, and the values ​​of two adjacent subfields may determine an interval. Thus, the N+1 subfields may 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., 6 ms. Optionally, the first subfield (or the (N+1)th subfield) may not be carried in the first field.

[0170]

[0185] The second field includes N sub-fields, whose values ​​represent the initial values ​​of the media synchronization delay timer, corresponding to the intervals.

[0171]

[0186] S302: A first multi-link device receives first indication information.

[0172]

[0187] S303: The first multi-link device determines an initial value of a media synchronization delay timer based on the length of the first PPDU transmitted on the first link, the initial value corresponding to the length of the first PPDU. The initial value is used to determine whether to start the media synchronization delay timer for the second link. The first multi-link device is not allowed to transmit and receive on the first link and the second link simultaneously.

[0173]

[0188] Specifically, the first multi-link device may be a non-AP MLD, and the non-AP MLD has non-STR capability. The first multi-link device may determine the initial value (or initial period) of the media synchronization delay timer based on the mapping relationship between the PPDU length and the initial value (or initial period) of the media synchronization delay timer, which corresponds to the PPDU length of the first PPDU, indicated by the first indication 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 a media synchronization delay timer for the second link based on an initial value (or initial period) of the media synchronization 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; alternatively, 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 starts the mediumSyncDelay timer for the second link may be understood (or stated) as follows: during the period when the mediumSyncDelay timer is running, the first multi-link device may use a more conservative channel access mechanism for the second link. The more conservative channel access mechanism may include, but is not limited to, the following: (1) using a low energy detection threshold (here, an ED threshold lower than -62 dBm) to determine whether the channel is busy; and (2) transmitting an RTS frame to attempt to detect channel availability is mandatory. Optionally, this may be a one-time attempt (or one 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 for 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 detection threshold used by the CCA operation is the first threshold; or, after the back-off counter for the second link backs off to 0, the first multi-link device is allowed 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, where the first channel in the single link and multi-access channel scenario corresponds to the second link, and the second channel in the single link and multi-access channel scenario corresponds to the first link. Details will not be 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 synchronization delay timer is indicated by the first indication information, so that the first multi-link device can determine the initial value of the medium synchronization delay timer, which corresponds 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 first multi-link device will not start the mediumSyncDelay timer for the second link, and if the initial value is greater than 0, the first multi-link device will start the mediumSyncDelay timer for the second link. Different PPDU lengths correspond to different initial values ​​of the mediumSyncDelay timer, which allows for more flexible setting of the mediumSyncDelay timer and improves 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 specified in a standard protocol. If the mapping relationship is specified in 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, i.e., the method for determining the initial period of the media synchronization delay timer may include step S303.

[0181]

[0196] Embodiment 4 Embodiment 4 of the present application provides a method for determining an energy detection threshold in a CCA process, in which an ED threshold used in the CCA process when backoff is performed on the second link within mediumSyncDelay is determined based on the length of a frame transmitted on the first link (or the second channel).

[0182]

[0197] 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 application. As shown in FIG. 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 indication information, where the second indication information is used to indicate a mapping relationship between a PPDU length and an energy detection threshold.

[0184]

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

[0185]

[0200] 10 is a schematic diagram of a mapping relationship between a PPDU length and an energy detection threshold according to an embodiment of the present application. As shown in FIG. 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 equal to or greater than 1 ms, the energy detection threshold is −82 dBm.

[0186]

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

[0187] [Table 2]

[0202] It should be understood that the mapping relationship shown in Figure 10 and Table 2 is merely an example, and that in a real application, the mapping relationship can be determined based on the actual application scenario. For example, the mapping relationship 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 in this embodiment of the present application.

[0188]

[0203] Optionally, the second indication may include an array. For example, the array (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 array (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 array (1000, maximum 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 maximum PPDU length. The maximum PPDU length is specified in the standard protocol.

[0189]

[0204] Optionally, the second indication information may include two fields: the first field is used to determine N intervals, and the second field is used to indicate initial values ​​corresponding to each of the N intervals.

[0190]

[0205] The first field may include N+1 subfields. The values ​​of the N+1 subfields increase monotonically, and the values ​​of two adjacent subfields may determine an interval. Thus, the N+1 subfields may 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., 6 ms. Optionally, the first subfield (or the (N+1)th subfield) may not be carried in the first field.

[0191]

[0206] The second field includes N subfields, whose values ​​represent the energy detection thresholds corresponding to the intervals.

[0192]

[0207] S402: The first multi-link device receives second indication 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 on the first link, and the energy detection threshold is used to determine whether to start a medium synchronization delay timer for the second link.

[0194]

[0209] Specifically, the first multi-link device may be a non-AP MLD, and the non-AP MLD may have non-STR capabilities. The first multi-link device may determine the energy detection threshold corresponding to the length of the first PPDU based on the mapping relationship between the PPDU length and the energy detection threshold indicated by the second indication information and 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 a medium synchronization delay timer for the second link based on the 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 a medium synchronization delay timer for the second link; alternatively, if the energy detection threshold determined in step S403 is less than -62 dBm, the first multi-link device starts a medium synchronization delay timer for the second link. If the first multi-link device starts a medium synchronization delay timer for the second link, this indicates that the first multi-link device sets the energy detection threshold used in CCA to the energy detection threshold corresponding to the length of the first PPDU (i.e., the energy detection threshold determined in step S504) during the mediumSyncDelay period when performing channel contention for the second link.

[0196]

[0211] The fact that the first multi-link device starts the mediumSyncDelay timer for the second link may be understood (or stated) as follows: during the period of the mediumSyncDelay timer, the first multi-link device may use a more conservative channel access mechanism for the second link. The more conservative channel access mechanism may include, but is not limited to, the following: (1) using a low energy detection threshold (here, an ED threshold lower than -62 dBm) to determine whether the channel is busy; and (2) transmitting an RTS frame to attempt to detect channel availability is mandatory. Optionally, this may be a one-time attempt (or one 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 for 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 detection threshold used by the CCA operation is the first threshold; or, after the back-off counter for the second link backs off to 0, the first multi-link device is allowed 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 the CCA process provided in this embodiment of the present application may alternatively be applied to a single link and multiple access channel scenario, where the first channel in the single link and multiple access channel scenario corresponds to the second link, and the second channel in the single link and multiple access channel scenario corresponds to the first link, and the details will not be described again here.

[0199]

[0214] In this embodiment of the present application, the mapping relationship between the PPDU length and the energy detection threshold is indicated by the second indication information, so that the first multi-link device determines 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 on the first link, and knows that if the energy detection threshold is equal to -62 dBm, the first multi-link device will not start the mediumSyncDelay timer for the second link, and if the energy detection threshold is greater than -62 dBm, the first multi-link device will start the mediumSyncDelay timer for the second link. Different PPDU lengths correspond to different energy detection thresholds. In this case, the channel access mechanism used on the second link is more flexible and improves channel access efficiency.

[0200]

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

[0201]

[0216] In another optional embodiment, the first indication information in embodiment 3 and the second indication information in embodiment 4 may be part of the indication information, or the first indication information and the second indication information may be carried in the same frame. Therefore, embodiments 3 and 4 may be combined into an embodiment. Specifically, a second multi-link device transmits indication information, where the indication 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 and a mapping relationship between the PPDU length and the energy detection threshold; a first multi-link device receives the indication information; the first multi-link device transmits a first PPDU on 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 that corresponds to the length of the first PPDU and an energy detection threshold that corresponds to the length of the first PPDU. Optionally, the first multi-link device may further determine whether to start a media synchronization delay timer for 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 content describes in detail the method provided in the present application. To better implement the aforementioned solution in the embodiments of the present application, the embodiments of the present application further provide a corresponding apparatus or device.

[0203]

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

[0204]

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

[0205]

[0220] In this design, the processing unit 12 is configured to: skip starting a medium synchronization delay timer for a second link if a length of a first PPDU transmitted by the first multi-link device on the first link is less than or equal to a first value; and the first multi-link device is not allowed to perform simultaneous transmission and reception on the first link and the second link.

[0206]

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

[0207]

[0222] It should be understood that the first multi-link device in this design can perform embodiment 2 accordingly, and the operations or functions of the units in the first multi-link device are individually used to implement the corresponding operations performed by the first multi-link device in embodiment 2. For the sake of brevity, the details will not be described again here.

[0208]

[0223] In this design, the processing unit 12 is configured to skip starting a medium synchronization delay timer for the second link if the type of the first frame transmitted by the first multi-link device on the first link is the first type, and the first multi-link device is not allowed to perform simultaneous transmission and reception on the first link and the second link.

[0209]

[0224] The processing unit 12 is specifically configured to set an energy detection threshold used by the CCA operation to a first threshold when channel contention is performed on the second link. Alternatively, the transceiver unit 11 is further configured to: transmit frames other than RTS frames and MU-RTS frames after a back-off counter on the second link backs off to 0. The first threshold may be −62 dBm.

[0210]

[0225] It should be understood that the first multi-link device in this design can perform embodiment 1 accordingly, and the operations or functions of the units in the first multi-link device are individually used to implement the corresponding operations performed by the first multi-link device in embodiment 1. For the sake of brevity, the details will not be described again here.

[0211]

[0226] In this design, the transceiver unit 11 is configured to receive first indication information, where the first indication information is used to indicate a mapping relationship between a PPDU length and an initial value of a media synchronization delay timer; the processing unit 12 is configured to determine an initial value of the media synchronization delay timer based on the length of the first PPDU transmitted on the first link, the initial value corresponding to the length of the first PPDU. The initial value is used to determine whether to start the media synchronization delay timer for the second link. The first multi-link device is not allowed to perform simultaneous transmission and reception on the first link and the second link.

[0212]

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

[0213]

[0228] Optionally, the processing unit 12 is specifically 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 alternatively, to 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] It should be understood that the first multi-link device in this design can perform embodiment 3 accordingly, and the operations or functions of the units in the first multi-link device are individually used to implement the corresponding operations performed by the first multi-link device in embodiment 3. For the sake of brevity, the details will not be described again here.

[0215]

[0230] In this design, the transceiver unit 11 is configured to receive second indication information, where the second indication information is used to specify a mapping relationship between a PPDU length and an energy detection threshold; and the processing unit 12 is configured to determine, based on the length of the first PPDU transmitted on the first link, an initial value of a medium synchronization delay timer, the initial value corresponding to the length of the first PPDU. The communication device is not allowed to perform simultaneous transmission and reception on the first link and the second link.

[0216]

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

[0217]

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

[0218]

[0233] It should be understood that the first multi-link device in this design can perform embodiment 4 accordingly, and the operations or functions of the units in the first multi-link device can be individually used to implement the corresponding operations performed by the first multi-link device in embodiment 4. For the sake of brevity, the details will not be described again here.

[0219]

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

[0220]

[0235] In the design, the processing unit 21 is configured to generate first indication information, where the first indication 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; and the transceiver unit 22 is configured to transmit the first indication information.

[0221]

[0236] It should be understood that the second multi-link device in this design can perform embodiment 3 accordingly, and the operations or functions of the units in the second multi-link device are individually used to implement the corresponding operations performed by the second multi-link device in embodiment 3. For the sake of brevity, the details will not be described again here.

[0222]

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

[0223]

[0238] It should be understood that the second multi-link device in this design can perform embodiment 4 accordingly, and the operations or functions of the units in the second multi-link device are individually used to implement the corresponding operations performed by the second multi-link device in embodiment 4. For the sake of brevity, the details will not be described again here.

[0224]

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

[0225]

[0240] In a possible product form, the first multi-link device and the second multi-link device described in the embodiments of the present 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 interconnect.

[0227]

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

[0228]

[0243] In the design, the processor is configured to: skip starting a medium synchronization delay timer for the second link if a type of a first frame transmitted by the first multi-link device on the first link is a first type, and the first multi-link device is not allowed to simultaneously transmit and receive on the first link and the second link.

[0229]

[0244] In one design, the transceiver is configured to receive first indication information, where the first indication information is used to indicate a mapping relationship between the length of the PPDU and an initial value of a media synchronization delay timer; and the processor is configured to determine an initial value of the media synchronization delay timer based on the length of the first PPDU transmitted on the first link, the initial value corresponding to the length of the first PPDU. The initial value is used to determine whether to start the media synchronization delay timer for the second link. The first multi-link device is not allowed to transmit and receive on the first link and the second link simultaneously.

[0230]

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

[0231]

[0246] The second multi-link device includes a processor and a transceiver that communicates with the processor via the interconnect.

[0232]

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

[0233]

[0248] In another design, the processor is configured to generate second indication information, where the second indication information 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 indication information.

[0234]

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

[0235]

[0250] A chip implementing the first multi-link device includes processing circuitry and an input / output interface that communicates with the processing circuitry via an interconnect.

[0236]

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

[0237]

[0252] In the design, the input / output interface is configured to receive the code instruction and transmit the code instruction to the processing circuit; the processing circuit is configured to skip starting a medium synchronization delay timer for the second link when a type of a first frame transmitted by the first multi-link device on the first link is a first type. The first multi-link device is not allowed to simultaneously transmit and receive on the first link and the second link.

[0238]

[0253] In this 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 and transmit the first instruction information to a processing circuit for processing, and obtain a mapping relationship between the PPDU length and an initial value (or initial period) of a media synchronization delay timer, the mapping relationship being indicated by the first instruction information; and the processing circuit is configured to determine an initial value of the media synchronization delay timer based on the length of the first PPDU transmitted on the first link, the initial value corresponding to the length of the first PPDU. The initial value is used to determine whether to start the media synchronization delay timer for the second link. The first multi-link device is not allowed to transmit and receive on the first link and the second link simultaneously.

[0239]

[0254] In this 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, and obtain a mapping relationship between the PPDU length and the 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 for the second link. The first multi-link device is not allowed to transmit and receive simultaneously on the first link and the second link.

[0240]

[0255] The chip implementing the second multi-link device includes processing circuitry and an input / output interface that communicates with the processing circuitry via an interconnect.

[0241]

[0256] In the 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 first instruction information, where 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; the input / output interface is configured to transmit the first instruction information to the 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 the processing circuit; the processing circuit is configured to generate second instruction information, where the second instruction information 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 the transceiver; and the transceiver is configured to transmit the second instruction information.

[0243]

[0258] In possible product forms, the first multi-link device and second multi-link device described in the embodiments herein may alternatively be implemented using one or more field programmable gate arrays (FPGAs), programmable logic devices (PLDs), controllers, state machines, gate logic, discrete hardware components, 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 types of communication devices may have some functions of the first multi-link device or the second multi-link device in the above method embodiments, and the details will not be described again here.

[0245]

[0260] An embodiment of the present application further provides a computer-readable storage medium having stored thereon instructions that, when executed on a computer, enable the computer to perform the method of any of the foregoing embodiments.

[0246]

[0261] An embodiment of the present application further provides a computer program product, which, when run on a computer, enables the computer to perform the method of any one of the aforementioned embodiments.

[0247]

[0262] An embodiment of the present application further provides a communication device. The device may exist in the form of a chip product. 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, so that the device performs the method of any one of the previous embodiments.

[0248]

[0263] The method or algorithm steps described in connection with the disclosure herein may be implemented by hardware or by a processor executing software instructions. The software instructions may include corresponding software modules. The software modules may be stored in random access memory (RAM), flash memory, erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), registers, a hard disk drive, a removable hard disk, a compact disk read-only memory (CD-ROM), or any other form of storage medium known in the art. For example, the storage medium may be coupled to the processor such that 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 the 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 the storage medium may reside as discrete components in a core network interface device.

[0249]

[0264] Those skilled in the art will recognize that in one or more of the foregoing examples, the functionality described herein may be implemented by hardware, software, firmware, or any combination thereof. When the present application is implemented by software, the functionality described herein may be stored on or transmitted as one or more instructions or code on a computer-readable medium. Computer-readable media include computer-readable storage media and communication media. Communication media include any medium that enables a computer program to be transmitted from one place to another. Storage media may be any available medium accessible to a general-purpose or special-purpose computer.

[0250]

[0265] The above specific embodiments further describe the objectives, technical solutions, and advantages of the present application. It should be understood that the above description is only a specific implementation of the present application and is not intended to limit the scope of protection of the present application. Any modifications, equivalent replacements, improvements, etc. made based on the technical solutions of the present application shall also fall within the scope of protection of the present application.

Claims

1. A channel access method for a multi-link device, comprising: a step of: when a media synchronization delay timer for a second link is started, if a length of a first PPDU transmitted by the first multi-link device on the first link is less than or equal to a first value, the first multi-link device skips updating the media synchronization delay timer for the second link; and the first multi-link device is not allowed to perform simultaneous transmission and reception on the first link and the second link.

2. 10. The method of claim 1, further comprising: The method includes receiving, by the first multi-link device, the first value, wherein the first value is carried in a beacon frame, an association response frame, or a reassociation response frame.

3. 3. The method of claim 1 or 2, further comprising: if the length of the first PPDU is greater than the first value, the first multi-link device determining an initial value for the media synchronization delay timer, the initial value corresponding to the length of the first PPDU, and starting the media synchronization delay timer using the initial value for the second link.

4. 4. The method of claim 3, further comprising: a step of receiving first indication information by the first multi-link device, the first indication information being used to indicate a mapping relationship between a PPDU length and an initial value of the media synchronization delay timer.

5. A first multi-link device comprising:

1. A first multi-link device comprising: a processing unit configured to start a media synchronization delay timer for a second link and to skip updating the media synchronization delay timer for the second link if a length of a first PPDU transmitted by the first multi-link device on the first link is less than or equal to a first value, wherein the first multi-link device is not allowed to perform simultaneous transmission and reception on the first link and the second link.

6. 6. The first multi-link device of claim 5, further comprising 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.

7. 7. The first multi-link device according to claim 5, wherein the processing unit is further configured to: determine an initial value of the media synchronization delay timer, the initial value corresponding to the length of the first PPDU, when the length of the first PPDU is greater than the first value; and start the media synchronization delay timer using the initial value for the second link.

8. 8. The first multi-link device according to claim 7, further comprising a transceiver unit configured to receive first indication information, the first indication information being used to indicate a mapping relationship between a PPDU length and an initial value of the media synchronization delay timer.

9. 1. A first multi-link device including a processor, the processor being configured to: skip updating a media synchronization delay timer for a second link if a media synchronization delay timer for the second link has been started and if a length of a first PPDU transmitted by the first multi-link device on the first link is less than or equal to a first value; and the first multi-link device is not allowed to perform simultaneous transmission and reception on the first link and the second link.

10. 1. A first multi-link device including an input / output interface and a processing circuit, wherein the input / output interface is configured to receive code instructions and transmit the code instructions to the processing circuit; and the processing circuit is configured to: start a media synchronization delay timer for a second link; and skip updating the media synchronization delay timer for the second link if a length of a first PPDU transmitted by the first multi-link device on the first link is less than or equal to a first value, wherein the first multi-link device is not allowed to perform simultaneous transmission and reception on the first link and the second link.

11. 5. A computer-readable storage medium having stored thereon program instructions that, when executed on a computer, enable the computer to perform the method of any one of claims 1 to 4.

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