Channel contention method and related device

Abstract

This application provides a channel contention method and a related apparatus.SOLUTION: The method includes: After data transmission on a first link is completed, or after a block acknowledgement corresponding to data on the first link is received, a first non-access point station of a first multi-link device performs clear channel assessment CCA detection on a second link within first duration, where a start moment corresponding to the first duration is the same as a moment at which the data transmission on the first link is completed, and when the CCA detection on the second link fails, the first non-access point station performs channel contention on the second link based on second duration. By means of implementation of the embodiments of this application, collision and interference between frames are avoided during channel contention.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] This application claims priority to Chinese Patent Application No. 202010820609.9, entitled "CHANNEL CONTENTION METHOD AND RELATED APPARATUS," filed with the State Intellectual Property Office of China on August 14, 2020, which is incorporated herein by reference in its entirety.

[0002] [Technical field] The present application relates to the field of communication technology, and more particularly to channel contention methods and related devices. [Background technology]

[0003] Next-generation wireless local area networks (WLANs) or cellular networks are currently being developed and evolved with the continuous technological goal of continuously improving throughput. WLAN system protocols were primarily discussed by the Institute of Electrical and Electronics Engineers (IEEE) standardization group. The next-generation Wi-Fi standard, IEEE 802.11be, is based on the previous standard protocols, IEEE 802.11a / b / g / n / ac / ax, and aims to achieve extremely high throughput (EHT). This standard focuses on multi-link communication. The core concept of multi-link communication is that WLAN devices compliant with the next-generation IEEE 802.11 standard are equipped with multi-band transmission and reception capabilities, thereby utilizing a larger bandwidth for data transmission and significantly improving throughput. Multiple bands include, but are not limited to, the 2.4 GHz Wi-Fi band, the 5 GHz Wi-Fi band, and the 6 GHz Wi-Fi band. The frequency band through which communication devices access and transmit is sometimes referred to as a link. Multiple frequency bands that a communication device accesses and transmits through are sometimes called multilinks. A station device that supports the next-generation IEEE 802.11 standard with multiple links is called a multilink device (MLD). A multilink device can support multilink communication. For example, FIG. 1 is a schematic diagram of a multilink communication scenario according to an embodiment of the present application. As shown in FIG. 1, an access point (AP) multilink device includes AP1 and AP2. A non-access point station (non-AP STA) MLD includes non-AP STA1 and non-AP STA2. AP1 communicates with non-AP STA1 via link 1. AP2 communicates with non-AP STA2 via link 2. Communication between an AP MLD and a STA MLD can be understood as multilink communication.

[0004] However, some multilink devices may not support simultaneous transmit and receive (STR) on multiple links in some cases. If the frequency spacing between multiple frequency bands supported by a non-STR (non-simultaneous transmit and receive) multilink device (hereinafter referred to as a non-STR multilink device) is small, channel interference may affect the clear channel assessment (CCA) of another link when transmitting data on one link. As a result, the other link may be determined to be in a blind period (or deaf period). A blind period means that information on the channel cannot be monitored. In this case, the existing solution, proposed in the 802.11-20 / 1009r1 standard, allows a non-STR MLD to set a medium sync delay timer on the other link after completing data transmission and perform CCA on the other link within the timer based on an energy detection (ED) threshold to be decided (TBD). If CCA detection fails on one link over another link, it means that an overlapping basic service set (OBSS) frame is being transmitted on that link. Once the OBSS frame transmission is finished, the non-STR MLD starts contending for the channel and initiates enhanced distributed channel access (EDCA).

[0005] However, after the transmission of the OBSS frame is completed, the corresponding transmission opportunity (TXOP) for the link may not end. As a result, after accessing the channel, the non-STR MLD may collide with the acknowledgment (ACK) frame corresponding to the OBSS frame. Therefore, how to avoid collisions and interference between frames during EDCA is a technical problem that needs to be solved immediately. Summary of the Invention

[0006] The present application provides a channel contention method and related devices that support non-simultaneous transmission / reception multi-link devices to reduce collisions and interference between frames during channel contention, thereby improving communication efficiency.

[0007] According to a first aspect, an embodiment of the present application provides a channel contention method, the method including: after completing data transmission on a first link or receiving a block acknowledgement corresponding to data on the first link, a first non-access point station of a first multilink device performs clear channel assessment (CCA) detection on a second link within a first time period, a start time corresponding to the first time period being the same as the time when the data transmission on the first link is completed, and when the CCA detection on the second link fails, the first non-access point station performs channel contention on the second link based on a second time period.

[0008] In this solution, after data transmission on the first link is completed or after a Block ACK corresponding to the data is received on the first link, CCA detection is performed on the second link, and if the CCA detection on the second link fails, channel contention is performed on the second link based on a second period, and after it is determined that data transmission on the second link is completed, collisions and interference between frames caused by channel contention on the second link are avoided, thereby reducing collisions and interference between frames and improving communication efficiency.

[0009] Optionally, the step of performing clear channel assessment CCA detection on the second link in the first time period comprises: the first non-access point station adjusts the CCA threshold to obtain an adjusted CCA threshold, the adjusted CCA threshold being less than the CCA threshold; The first non-access point station performs CCA detection on the second link for the first time period based on the adjusted CCA threshold.

[0010] It can be seen that in this solution, when CCA detection is performed on the second link, a stricter CCA threshold is used to perform CCA detection on the second link, thereby avoiding collisions and interference between subsequent frames that occur when channel contention is performed on the second link after it is determined that data transmission on the second link is completed.

[0011] Optionally, the CCA threshold comprises an energy detection threshold or an intermediate energy detection threshold.

[0012] Optionally, the step of performing channel contention on the second link based on a second time period includes: If the end time corresponding to the second time period is earlier than the end time corresponding to the first time period, the first non-access point station performs channel contention on the second link after the end time corresponding to the second time period; or If the end time corresponding to the second time period is later than the end time corresponding to the first time period, the first non-access point station performs channel contention on the second link after the end time corresponding to the first time period or after the end time corresponding to the second time period.

[0013] In this solution, it can be understood that by performing channel contention on the second link in different cases after the end point corresponding to the first period or after the end point corresponding to the second period, collisions and interference between frames that occur when channel contention is performed on the second link after it is determined that data transmission on the second link is completed are avoided, thereby reducing collisions and interference between frames and improving communication efficiency.

[0014] Optionally, the method comprises: a step of the first non-access point station updating a network allocation vector NAV based on a radio frame to obtain an updated NAV, the radio frame being a radio frame transmitted to a second non-access point station of a second link when data is being transmitted on the first link or a Block Ack corresponding to the data is being transmitted on the first link, the second non-access point station being a non-access point station other than the first non-access point station of the first multi-link device; The first non-access point station further includes performing channel contention on the second link based on the updated NAV.

[0015] It can be seen that this solution performs channel contention detection on the second link based on the updated NAV, and avoids inter-frame collisions and interference that occur when channel contention is performed on the second link after it is determined that data transmission on the second link is complete, thereby reducing inter-frame collisions and interference and improving communication efficiency.

[0016] Optionally, the step of performing channel contention on the second link based on the updated NAV includes: If the updated NAV is less than the time when data transmission on the first link is completed or when a Block ACK is received on the first link, the first non-access point station performs CCA detection on the second link during the first period; If the CCA detection fails on the second link, the first non-access point station performs channel contention on the second link based on a second time period; or If the updated NAV is greater than when the data transmission is completed on the first link or when a Block ACK is received on the first link, the first non-access point station performs channel contention on the second link when the updated NAV backs off to 0.

[0017] It can be seen that this solution avoids inter-frame collisions and interference that occur when channel contention detection is performed on the second link in a different case and channel contention is performed on the second link after it is determined that data transmission on the second link is complete, thereby reducing inter-frame collisions and interference and improving communication efficiency.

[0018] Optionally, the second period is an extended inter-frame space (EIFS) time.

[0019] According to a second aspect, an embodiment of the present application provides a communication device applied to a first multi-link device, which may be the first multi-link device or a chip in the first multi-link device, such as a Wi-Fi chip. The communication device includes a processing unit, which: configured to perform clear channel assessment CCA detection on a second link within a first period by a first non-access point station of a first multilink device after completing data transmission on a first link or receiving a block acknowledgement corresponding to data on the first link, wherein a start time corresponding to the first period is the same as a time when the data transmission on the first link is completed; The processing unit is further configured to perform, by the first non-access point station, channel contention on the second link based on a second time period when the CCA detection on the second link fails.

[0020] Optionally, when clear channel assessment CCA detection is performed on the second link in the first time period, the processing unit: adjusting the CCA threshold to obtain an adjusted CCA threshold, and the adjusted CCA threshold is smaller than the CCA threshold; and configured to perform CCA detection on the second link during the first time period based on the adjusted CCA threshold.

[0021] Optionally, the CCA threshold comprises an energy detection threshold or an intermediate energy detection threshold.

[0022] Optionally, when channel contention is performed on the second link based on a second time period; If the end time corresponding to the second time period is earlier than the end time corresponding to the first time period, the processing unit is configured to perform channel contention on the second link after the end time corresponding to the second time period; or If the end time corresponding to the second time period is later than the end time corresponding to the first time period, the processing unit is configured to perform channel contention on the second link after the end time corresponding to the first time period or after the end time corresponding to the second time period.

[0023] Optionally, the processing unit: updating a network allocation vector NAV based on a radio frame to obtain an updated NAV, the radio frame being a radio frame transmitted to a second non-access point station of a second link when data is being transmitted on the first link or a block ACK corresponding to the data is being transmitted on the first link, the second non-access point station being a non-access point station other than the first non-access point station of the first multi-link device; It is further configured to perform channel contention on the second link based on the updated NAV.

[0024] Optionally, when channel contention is performed on the second link based on the updated NAV, If the updated NAV is less than the time when data transmission is completed on the first link or when a Block Ack is received on the first link, the processing unit performs CCA detection on the second link during the first period; configured, by the first non-access point station, to perform channel contention on the second link based on a second time period if CCA detection on the second link fails; or If the updated NAV is greater than the time when data transmission is completed on the first link or when a Block ACK is received on the first link, the processing unit is configured to perform channel contention on the second link when the updated NAV backs off to 0.

[0025] Optionally, the second period is an extended inter-frame space (EIFS) time.

[0026] According to a third aspect, an embodiment of the present application provides a communication device, specifically a first multi-link device, which has a function of performing the operation of the first multi-link device in the above-mentioned method. The function may be implemented by hardware or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above-mentioned functions.

[0027] In one possible design, the first multilink device includes a processor and a transceiver. The processor is configured to support the first multilink device in performing corresponding functions in the manner described above. The transceiver is configured to support communications for the first multilink device and to receive information, frames, data packets, or instructions in the manner described above. The first multilink device may further include a memory. The memory is coupled to the processor and stores program instructions and data required for the first multilink device.

[0028] According to a fourth aspect, an embodiment of the present application provides a wireless communication system, the system including a first multilink device according to the third aspect.

[0029] According to a fifth aspect, an embodiment of the present application provides a chip or chip system including an input / output interface and a processing circuit, the input / output interface being used for information or data exchange, the processing circuit being configured to execute instructions, and a device incorporating the chip or chip system performing a channel contention method according to any of the above aspects.

[0030] According to a sixth aspect, an embodiment of the present application provides a computer-readable storage medium. The computer-readable storage medium stores instructions. The instructions can be executed by one or more processors on a processing circuit. When the instructions are executed on a computer, the computer is enabled to perform the channel contention method in any one of the aforementioned aspects.

[0031] According to a seventh aspect, the present application provides a computer program product comprising instructions, which, when executed on a computer, enable the computer to perform the channel contention method of any one of the preceding aspects.

[0032] According to an eighth aspect, the present application provides a chip system. The chip system includes a processor and is configured to support a device in which the chip system is installed in implementing a channel contention method according to any of the above aspects, for example, in processing frames and / or information using the above channel contention method. In a possible design, the chip system further includes a memory. The memory is configured to store program instructions and data necessary for the data transmission device. The chip system may include a chip, or may include a chip and other discrete components. [Brief explanation of the drawings]

[0033] The following briefly describes the accompanying drawings used in the embodiments or prior art.

[0034] [Figure 1] 1 is a schematic diagram of a multi-link communication scenario according to an embodiment of the present application;

[0035] [Figure 2A] FIG. 2 is a schematic diagram of setting a NAV according to an embodiment of the present application;

[0036] [Figure 2B] FIG. 10 is another schematic diagram of setting NAV according to an embodiment of the present application.

[0037] [Figure 3] 1 is a schematic diagram of the architecture of a wireless communication system according to an embodiment of the present application;

[0038] [Figure 4] 1 is a schematic diagram of a structure of a multi-link device according to an embodiment of the present application;

[0039] [Figure 5] 1 is a schematic diagram of another structure of a multi-link device according to an embodiment of the present application;

[0040] [Figure 6] FIG. 1 is a schematic diagram of a contention channel according to an embodiment of the present application;

[0041] [Figure 7] FIG. 10 is a schematic diagram of another contention channel according to an embodiment of the present application.

[0042] [Figure 8] 1 is a schematic diagram of a channel contention method according to an embodiment of the present application;

[0043] [Figure 9] 1 is a schematic diagram of a timeline of a channel contention method according to an embodiment of the present application;

[0044] [Figure 10] FIG. 2 is another timeline schematic diagram of a channel contention method according to an embodiment of the present application;

[0045] [Figure 11] FIG. 2 is a schematic diagram of another channel contention method according to an embodiment of the present application;

[0046] [Figure 12] FIG. 2 is another timeline schematic diagram of a channel contention method according to an embodiment of the present application;

[0047] [Figure 13] FIG. 2 is another timeline schematic diagram of a channel contention method according to an embodiment of the present application;

[0048] [Figure 14] 1 is a schematic diagram of the structure of a communication device according to an embodiment of the present application;

[0049] [Figure 15] 1 is a schematic diagram of another structure of a communication device according to an embodiment of the present application; DETAILED DESCRIPTION OF THE INVENTION

[0050] The following describes the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present application.

[0051] To facilitate understanding of the technical solutions in the embodiments of the present application, the following briefly explains the meanings of some nouns (or terms) in the embodiments of the present application.

[0052] 1. Transmission Opportunity (TXOP)

[0053] TXOP duration is the period of time that a station (here, a station may represent an access point or a non-access point station) transmits data without interference after obtaining a transmission opportunity. A station that obtains a TXOP is sometimes called a TXOP holder. TXOP duration includes the duration required for the TXOP holder to transmit one or more data and a corresponding immediate response frame (here, an immediate response frame may represent an ACK frame, a Block ACK, etc.). Depending on the laws of a country or region, the TXOP duration cannot exceed an upper limit. The upper limit is called the TXOP limit. The value of the TXOP limit is subject to the laws of a country and / or region.

[0054] Optionally, the AP can broadcast the value of the TXOP limit using a beacon frame or a probe response frame.

[0055] Optionally, the TXOP limit is further associated with the access category (also called access type, or AC) for which contention provides a transmission opportunity. Specifically, Table 1 shows the TXOP limit values ​​corresponding to four different access categories, where AC_VO indicates the access category is a voice stream, AC_VI indicates the access category is a video stream, AC_BE indicates the access category is a best effort stream, and AC_BK indicates the access category is a background stream. Table 1: TXOP limits for different access categories [Table 1]

[0056] Optionally, the priority of the audio stream, the priority of the video stream, the priority of the best effort stream, and the priority of the background stream decrease in order, i.e., the priority is AC_VO, AC_VI, AC_BE, AC_BK in descending order, where a higher priority indicates a higher channel preemption capability.

[0057] The terms "data transmission" and "transmitted data" used in the embodiments of the present application can be understood to generally refer to communication. "Data" generally refers to communication information, and is not limited to data information, and may include signaling information, etc.

[0058] 2. Network Allocation Vector (NAV)

[0059] Virtual carrier sense is a type of carrier sense. The channel state is learned through control information rather than actually sensing the physical channel. Specifically, virtual carrier sense performs logical prediction based on relevant information transmitted in medium access control (MAC) frames. That is, each frame transmits the duration information of the next frame for the transmitting station, and each station associated with the transmitting station predicts the channel occupancy based on the duration information. If a station does not monitor the duration information, for example, if the duration field of the frame is transmitted when the carrier is sensed, the station may rely solely on physical layer detection.

[0060] Virtual Carrier Sense can be implemented using the Network Allocation Vector (NAV). The NAV is essentially a countdown timer that gradually decrements over time. When the NAV counts down to 0, the medium is considered idle. Therefore, the timing value of the NAV is set and updated by the Virtual Carrier Sense at the appropriate time with the appropriate value. Specifically, after a station receives a frame, if the recipient address of the frame is not a station, the station can update its NAV based on the duration field of the received frame. If the recipient address of the frame is a station, it indicates that the station is the receiving station and may not be able to update its NAV.

[0061] Optionally, before the NAV is updated, it 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 is greater than the current NAV value, the NAV is updated. Conversely, if the value is less than or equal to the current NAV value, the NAV is not updated. The NAV value starts from the end of the received frame.

[0062] It can be appreciated that the duration field can be used to inform other non-receiving stations of the duration for which the channel is occupied in order to prevent other non-receiving stations from accessing the channel and transmitting data.

[0063] Optionally, after obtaining the TXOP, the transmitting station can set the value of the duration field so that the TXOP duration does not exceed the TXOP limit.

[0064] FIG. 2A is a schematic diagram of NAV setting according to an embodiment of the present application. As shown in FIG. 2A, after acquiring a TXOP, a transmitting station sets the value of the duration field in a first transmission frame (e.g., the request to send (RTS) frame in FIG. 2A) so that the TXOP duration does not exceed the TXOP limit. Then, the transmitting station sets the value of the duration field in a subsequent frame so that the end time corresponding to the duration field of the subsequent frame is the same as the end time corresponding to the duration field of the previous frame. Note that the RTS frame includes a duration field, and Aggregate Medium Access Control Protocol Data Unit (A-MPDU) 1 and A-MPDU 2 also include a duration field. For an RTS frame, the value in the duration field of the RTS frame is greater than the value in the duration field of A-MPDU 1, and the value in the duration field of A-MPDU 1 is greater than the value in the duration field of A-MPDU 2. However, as shown in Figure 2A, it can be seen that the NAV corresponding to the RTS frame, the NAV corresponding to A-MPDU1, and the NAV corresponding to A-MPDU2 have the same end time. That is, after the non-receiving station individually updates its NAV based on the duration field included in the RTS frame, the duration field included in A-MPDU1, and the duration field included in A-MPDU2, the NAV corresponding to the RTS frame, the NAV corresponding to A-MPDU1, and the NAV corresponding to A-MPDU2 will have the same end time. It can be seen from Figure 2A that the value of the duration field included in the RTS frame may be the same as the TXOP duration.

[0065] FIG. 2B is another schematic diagram of NAV setting according to an embodiment of the present application. As shown in FIG. 2B, after a transmitting station acquires a TXOP, if the value of the duration field set in the first transmission frame (e.g., the RTS frame in FIG. 2B) is smaller than the TXOP limit, or if the initially set TXOP duration is smaller than the TXOP limit, the value of the duration field can be set in a subsequent frame, so that the current TXOP duration exceeds the end point of the previous TXOP duration. However, starting from the initially set TXOP duration, the total TXOP duration cannot exceed the TXOP limit. The RTS frame includes a duration field, and the A-MPDU1 also includes a duration field. As shown in FIG. 2B, it can be seen that end point 1 of the NAV corresponding to the RTS frame is earlier than end point 2 of the NAV corresponding to the A-MPDU1. That is, after the non-receiving station individually updates its NAV based on the duration field included in the RTS frame and the duration field included in the A-MPDU1, end point 1 of the NAV corresponding to the RTS frame is earlier than end point 2 of the NAV corresponding to the A-MPDU1. In addition, the end point 1 of the NAV corresponding to the RTS frame and the end point 2 of the NAV corresponding to A-MPDU1 are both earlier than the TXOP limit. This means that the end points of the NAV corresponding to frames transmitted after the transmission of the RTS frame will also be earlier than the TXOP limit. In other words, starting from the initially set TXOP duration, the total TXOP duration cannot exceed the TXOP limit. It can be seen that non-receiving stations update their NAVs based on each frame they receive.

[0066] The above content has briefly explained the meanings of some nouns (or terms) in the embodiments of the present application. In order to better understand the channel contention method provided in the embodiments of the present application, the following describes the system architecture and / or application scenarios of the channel contention method provided in the embodiments of the present application. It can be understood that the scenarios described in the embodiments of the present application are intended to more clearly explain 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.

[0067] The technical solution method in the embodiment of the present application may be applied to a wireless communication system. The wireless communication system may be a wireless local area network (WLAN) or a cellular network. The method in the embodiment of the present application may be implemented by a communication device in the wireless communication system or a chip or processor in the communication device in the embodiment of the present application. The communication device may be a wireless communication device that does not support STR. For example, the communication device may be called a multi-link device or a multi-band device. Compared with a communication device that only supports single-link transmission, a multi-link device has higher transmission efficiency and higher throughput.

[0068] A multilink device includes one or more affiliated stations (STAs). A dependent station is a logical station and may operate on one link. A dependent station may be an access point (AP) or a non-access point station (non-AP STA). For ease of explanation, in this application, a multilink device that has an AP as its affiliated station may be referred to as a multilink AP, a multilink AP device, or an AP multilink device (AP MLD). A multilink device that has a non-AP STA as its affiliated station may be referred to as a multilink STA, a multilink STA device, or an STA multilink device (STA MLD). For ease of explanation, in the embodiments of this application, "a multilink device includes an affiliated station" may also be simply written as "a multilink device includes a station."

[0069] Optionally, a multilink device includes multiple logical stations. Each logical station operates on one link, although multiple logical stations are permitted to operate on the same link. A link identifier, as described below, represents one station operating on one link. That is, if there are multiple stations on one link, multiple link identifiers must represent the multiple stations. A link, as referred to below, sometimes also represents the stations operating on that link.

[0070] During data transmission, the AP multilink device and the STA multilink device may use a link identifier to identify a link or a station on a link. Prior to communication, the AP multilink device and the STA multilink device may mutually negotiate or communicate the correspondence between the link identifier and a link or a station on a link. Therefore, during data transmission, the link identifier is carried without transmitting a large amount of signaling information indicating the link or the station on the link. This reduces signaling overhead and improves transmission efficiency.

[0071] In an example, when an AP multilink device establishes a basic service set (BSS), a transmitted management frame (e.g., a beacon frame) carries an element including multiple link identifier information fields. Each link identifier information field can indicate a correspondence between a link identifier and a station operating on the link. Each link identifier information field includes a link identifier and can further include one or more of a MAC address, an operating set, and a channel number, where one or more of the MAC address, operating set, and channel number can indicate the link. As another example, during a multilink association process, the AP multilink device and the STA multilink device negotiate multiple link identifier information fields. In subsequent communications, the AP multilink device or the STA multilink device uses the link identifier to identify or represent a station within the multilink device. The link identifier can further indicate one or more attributes of the station's MAC address, operating set, and channel number. The MAC address can alternatively be the association identifier (AID) of the associated AP multilink device.

[0072] If multiple stations are operating on a link, the link identifier (which is a numeric ID) includes the operating set and channel number of the link, and also includes the identifier of the station operating on the link, for example the station's MAC address or association identifier AID.

[0073] The multilink device may implement wireless communication in accordance with the IEEE 802.11 series protocol. For example, the multilink device may be a station conforming to the ultra-high throughput standard, or may be a station based on or compatible with IEEE 802.11be, and may communicate with another device.

[0074] The channel contention method provided in the embodiments of the present application may be applied to a scenario in which one node transmits data to one or more nodes, or may be applied to a single-user uplink / downlink data transmission scenario, a multi-user uplink / downlink data transmission scenario, or a device-to-device (D2D) data transmission scenario.

[0075] Any one of the aforementioned nodes may be an AP multilink device or a multilink non-AP device. For example, the scenario may be a scenario in which an AP multilink device performs data transmission with one or more non-AP multilink devices, or a scenario in which a non-AP multilink device performs data transmission with one or more AP multilink devices, or a scenario in which a non-AP multilink device performs data transmission with a non-AP multilink device, or a scenario in which an AP multilink device performs data transmission with an AP multilink device. This is not limited to this embodiment of the present application. Furthermore, the channel contention method provided in this embodiment of the present application may also be applied to legacy stations that only support transmission on a single link. This is not limited here.

[0076] FIG. 3 is a schematic diagram of the architecture of a wireless communication system according to an embodiment of the present application. FIG. 3 uses a wireless local area network as an example. The wireless communication system includes one AP multilink device 100 and one or more non-AP multilink devices (e.g., non-AP multilink device 200, non-AP multilink device 300, and non-AP multilink device 400 in FIG. 3). The AP multilink device is a multilink device that provides services to the non-AP multilink devices, and the non-AP multilink device can communicate with the AP multilink device via multiple links to improve throughput. The number of AP multilink devices and the number of non-AP multilink devices in FIG. 3 are merely examples.

[0077] For example, a multilink device (e.g., any of the AP multilink device 100, the non-AP multilink device 200, the non-AP multilink device 300, and the non-AP multilink device 400 in FIG. 3) is a device with wireless communication capabilities. The device may be an entire device, or a chip, processing system, etc., mounted within the entire device. A device mounted with a chip or processing system may implement the methods and functions of the present embodiment under the control of the chip or processing system. For example, the non-AP multilink device in the present embodiment may have wireless transceiver capabilities, support 802.11 series protocols, and be able to communicate with an AP multilink device or another AP multilink device. For example, the non-AP multilink device is any user communication device that allows a user to communicate with an AP and further with a WLAN. For example, the Non-AP multilink device may be a user device that can connect to a network, such as a tablet computer, a desktop computer, a laptop computer, a notebook computer, an ultra-mobile personal computer (UMPC), a handheld computer, a netbook, a personal digital assistant (PDA), or a mobile phone; an Internet of Things node in the Internet of Things; or an in-vehicle communication device in the Internet of Vehicles. Alternatively, the Non-AP multilink device may be a chip and processing system within the above-mentioned terminal. The AP multilink device in the present embodiment is a device that provides services to the Non-AP multilink device and may support 802.11 series protocols. For example, the AP multilink device may be a communication entity such as a communication server, a router, a switch, or a bridge, or may include various forms of a macro base station, a micro base station, a relay station, or the like. Of course, the AP multilink device may alternatively be a chip and processing system within various forms of devices to implement the methods and functions of the present embodiment.

[0078] It can be understood that the multilink device may support high-speed and low-latency transmission. With the continuous evolution of application scenarios for wireless local area networks, the multilink device 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 devices in smart homes (e.g., smart cameras, projectors, displays, televisions, stereos, refrigerators, and washing machines), nodes in the Internet of Things, entertainment terminals (e.g., wearable devices such as AR and VR), smart devices in smart offices (e.g., printers and projectors), Internet of Vehicles devices in the Internet of Vehicles, and some infrastructure in daily life scenarios (e.g., vending machines, self-service navigation stations in supermarkets, self-service checkout registers, self-service ordering machines, etc.). The specific types of the non-AP multilink device and the AP multilink device are not limited in the embodiments of the present application and are described here merely as examples. The 802.11 protocol may support 802.11be or be compatible with 802.11be.

[0079] Optionally, FIG. 4 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 media access control (MAC) layer within the multi-link device. As shown in FIG. 4, multiple non-AP STAs included in the multi-link device are independent of each other at the low MAC layer and PHY layer, and are also independent of each other at the high MAC layer. FIG. 5 is a schematic diagram of another multi-link device structure according to an embodiment of the present application. As shown in FIG. 5, multiple non-APs included in the multi-link device are independent of each other at the low MAC layer and PHY layer, and share the high MAC layer. Of course, in multi-link communication processing, non-AP multi-link devices may use a structure in which the high MAC layer is independent of each other, while AP multi-link devices use a structure in which the high MAC layer is shared. Alternatively, non-AP multi-link devices may use a structure in which the high MAC layer is shared, and AP multi-link devices use a structure in which the high MAC layer is independent of each other. Alternatively, both the non-AP multilink device and the AP multilink device may use a structure in which the upper MAC layer is shared. Alternatively, both the non-AP multilink device and the AP multilink device may use a structure in which the upper MAC layers are independent of each other. The schematic diagram of the internal structure of the multilink device is not limited in the embodiments of the present application. Figures 4 and 5 are merely examples for explanation. For example, the upper MAC layer or the lower MAC layer may be implemented by a single processor in the chip system of the multilink device, or by different processing modules in the chip system.

[0080] For example, the multilink device in the embodiments of the present application may be a single-antenna device or a multi-antenna device. For example, the multilink device may be a device with two or more antennas. The number of antennas included in the multilink device is not limited in the embodiments of the present application. In the embodiments of the present application, the multilink device may allow services of the same access category to be transmitted over different links, or may allow the same data packet to be transmitted over different links. Alternatively, the multilink device may not allow services of the same access category to be transmitted over different links, but may allow services of different access categories to be transmitted over different links.

[0081] The frequency bands in which the multilink device operates include one or more of the following frequency bands: sub-1 GHz, 2.4 GHz, 5 GHz, 6 GHz, and high frequency 60 GHz.

[0082] Optionally, FIG. 6 is a schematic diagram of a contention channel according to an embodiment of the present application. As shown in FIG. 6, it can be seen that AP1 and AP2 are included in the AP MLD. AP3 is not included in the AP MLD. AP3 may be a single device or may be subordinate to another AP MLD. AP1 operates on link 1, and AP2 operates on link 2. The non-AP MLD includes non-AP STA1 and non-AP STA2. The non-AP MLD does not include non-AP3. Non-AP3 may be a single device or may be subordinate to another non-AP MLD. Non-AP STA1 operates on link 1, and non-AP STA2 and non-AP STA3 operate on link 2. Non-AP STA1 transmits a Request To Send (RTS) frame to AP1 on link 1. After receiving the request to send frame on link 1, AP1 may respond with a clear to send (CTS) frame to non-AP STA1 on link 1. After receiving the clear to send frame on link 1, non-AP STA1 may transmit a data frame to AP1 on link 1. After receiving the data frame on link 1, AP1 may transmit a block ACK to non-AP STA1 on link 1.

[0083] Note that because the frequency interval between the frequency bands of Link 1 and Link 2 is small, channel interference may affect CCA on Link 2 when transmitting data on Link 1. In this case, channel information on Link 2 may not be received. In other words, Link 2 is in a blindness period (or deaf period). A blind period means that information on the channel cannot be monitored. Also, when transmitting data on Link 1, even if Non-AP STA 2 sends a frame transmission request on Link 2, the frame transmission request may not be received due to channel interference. As a result, Non-AP STA 2 may miss an update of the network allocation vector (NAV).

[0084] Also, as shown in Figure 6, after data transmission on Link 1 is completed, Non-AP STA3 starts channel contention. Furthermore, Non-AP STA3 transmits a frame transmission request on Link 2, and Non-AP STA3 also receives a frame transmission permission on Link 2. After that, Non-AP STA3 can transmit a data frame to AP2 on Link 2. At this time, a frame transmission request is being transmitted on Link 2. In other words, the data frame transmitted by Non-AP STA3 to AP2 on Link 2 collides with the frame transmission request on Link 2. Therefore, the collision problem in this case is a blind problem.

[0085] To solve the aforementioned problem, the 802.11-20 / 1009r1 standard proposes that after data transmission is completed, a non-STR MLD can set a medium sync delay (MSD) timer on another link and perform CCA on that link within the timer based on an energy detection (ED) threshold to be determined (TBD). If CCA detection fails on one link of another link, it means that an overlapping basic service set (OBSS) frame is being transmitted on that link. When the transmission of the OBSS frame ends, the non-STR MLD starts contending for the channel and initiates enhanced distributed channel access (EDCA). That is, when the transmission of the OBSS frame ends, a frame transmission request is sent on the link. However, the transmission opportunity (TXOP) corresponding to the OBSS frame on the link may not end. That is, the block ACK corresponding to the OBSS frame is still being transmitted on the link. Therefore, the block ACK corresponding to the OBSS frame on the link collides with the frame transmission request on the link.

[0086] FIG. 7 is a schematic diagram of another contention channel according to an embodiment of the present application. As shown in FIG. 7, the STRAP MLD includes AP1 and AP2. The STR AP MLD does not include AP3. AP3 may be a single device or may be subordinate to another AP MLD. AP1 operates on link 1, and AP2 and AP3 operate on link 2. The non-STR non-AP MLD includes non-AP STA1 and non-AP STA2. The non-STR non-AP MLD does not include non-AP3. Non-AP3 may be a single device or may be subordinate to another non-AP MLD. Non-AP STA1 operates on link 1, and non-AP STA2 and non-AP STA3 operate on link 2.

[0087] When Non-AP STA1 transmits an uplink PPDU to AP1 on Link 1, Link 2 is in a blind period (see the blind period of Non-AP STA2 in Figure 7) due to the small frequency spacing between the frequency bands of Link 1 and Link 2. When data transmission on Link 1 is completed, Non-AP STA2 starts a medium sync delay timer. That is, the end of the uplink PPDU on Link 1 is aligned with the start of the medium sync delay. Within the medium sync delay, Non-AP STA2 performs CCA detection on Link 2 based on a TBD (To be decided) energy detection (ED) threshold, for example, -82dbm to -62dbm. In this case, when a downlink PPDU is being transmitted on Link 2, i.e., when the start of the downlink PPDU on Link 2 is earlier than the time when CCA detection is performed on Link 2 and the end of the downlink PPDU on Link 2 is aligned / same as the time when CCA detection is successful, Non-AP STA2 determines that Link 2 is busy. As shown in FIG. 7, when Non-AP STA2 determines that Link 2 is busy, it means that Non-AP STA2 considered Link 2 to be "CCA busy" before the end of the downlink PPDU (TA indicates AP3, RA indicates Non-AP STA3). The end of the downlink PPDU is also the start of "CCA detection success," which means that Non-AP STA2 has determined or detected that Link 2 is no longer busy. In this case, Non-AP STA2 begins backoff. That is, when the downlink PPDU transmission on Link 2 is completed, Non-AP STA2 starts EDCA on Link 2. As shown in Figure 7, the start point of Non-AP STA2 backoff on Link 2 is the point when the downlink PPDU transmission is completed, which is different from the start point of Non-AP STA2 backoff in Figure 9. Note that a stricter ED threshold can also be used. As a result, Non-AP STA2 determines that Link 2 is busy.Those skilled in the art know that CCA busy means that the detected signal exceeds the ED threshold, and CCA idle means that the detected signal does not exceed the ED threshold. Non-AP STA2 may miss a packet header. As a result, it cannot update its NAV. Therefore, after the updated NAV is completed, Non-AP STA2 cannot start EDCA on Link 2. As shown in FIG. 7, Non-AP STA2 is blinded at the start of the downlink PPDU (TA indicates AP3, and RA indicates Non-AP STA3) on Link 2. In this case, Non-AP STA2 cannot detect or receive the DL PPDU.

[0088] Furthermore, Non-AP STA2 may send a frame transmission request to AP2 on Link 2. For the frame transmission request, see RTS in Figure 7 (TA indicates Non-AP STA2, and RA indicates AP2). However, the transmission opportunity (TXOP) corresponding to the downlink PPDU on Link 2 may not end. That is, a Block ACK corresponding to the downlink PPDU is being sent on Link 2 (the Block ACK may not be detected by Non-STR Non-AP MLD, and as a result, the NAV cannot be updated). For the Block ACK, see BA in Figure 7 (TA indicates Non-AP STA3, and RA indicates AP3). As shown in Figure 7, it can be seen that the start of the Block ACK corresponding to the downlink PPDU on Link 2 is aligned / same as the start of the frame transmission request sent to AP2 on Link 2. That is, the Block ACK corresponding to the downlink PPDU on Link 2 collides with the frame transmission request sent to AP2 on Link 2. As shown in FIG. 7, the aforementioned “collision” specifically means that the start of the Block Ack corresponding to the downlink PPDU on Link 2 at least overlaps with the duration of the Frame Transmission Request sent to AP2 on Link 2.

[0089] Those skilled in the art will understand that when Non-AP STA2 "misses a packet header," it means that Non-AP STA2 does not detect or receive the packet header of the PPDU. Those skilled in the art will know that the packet header of the PPDU is a preamble and includes at least fields such as L-LTF, L-STF, and L-SIG. Not detecting the header of the PPDU is equivalent to Non-AP STA2 regarding the PPDU as not starting.

[0090] Therefore, in order to avoid collisions and interference between frames during channel contention, this application proposes a channel contention method to support non-simultaneous transmission and reception multi-link devices that reduce collisions and interference between frames during channel contention, thereby improving communication efficiency.

[0091] The channel contention method provided in this embodiment of the present application will be described in detail below with reference to Figures 8 to 13. In this embodiment of the present application, the first multi-link device is used to describe the method.

[0092] In some possible implementations, one or more of the first and second multilink devices in this embodiment of the present application do not support simultaneous transmit and receive (STR) on multiple links. It should be understood that "supporting STR" as used herein may mean that the multilink device has the STR function and uses the STR function in this communication, and that "not supporting STR" may mean that the multilink device does not have the STR function, or that the multilink device has the STR function but does not use the STR function in this communication. It should also be understood that in some cases, the multilink device may implement switching between STR and non-STR, i.e., switching from supporting STR to not supporting STR, or switching from not supporting STR to supporting STR. The following describes the channel contention method provided in this embodiment of the present application using an example in which the first multilink device does not support STR and the second multilink device supports STR.

[0093] Optionally, the first multilink device referred to in this embodiment of the present application may be the non-AP multilink device 200 of FIG. 3, and the second multilink device may be the AP multilink device 100 of FIG. 3. For simplicity of explanation, it may be understood that the following describes an example in which the non-AP multilink device 200 includes two non-AP STAs. The first non-access point station referred to in this embodiment of the present application may be any STA in the non-AP multilink device 200, and the second non-access point station is another STA in the non-AP multilink device 200. The first access point referred to in this embodiment of the present application is any AP in the AP multilink device 100. In this embodiment of the present application, two links are used as an example for explanation. In actual applications, multiple (two or more) links may exist. For the implementation of multiple links, refer to the implementation of two links provided in this embodiment of the present application. Details will not be described again here.

[0094] 8 is a schematic diagram of a channel contention method according to an embodiment of the present application. As shown in FIG. 8, the channel contention method provided in this embodiment of the present application includes, but is not limited to, the following steps:

[0095] 801: After completing data transmission on a first link or receiving a block ACK corresponding to the data on the first link, a first non-access point station of a first multi-link device performs clear channel assessment CCA detection on a second link during a first period.

[0096] The data transmitted on the first link may be a radio frame such as a data frame or a management frame, which is not limited here.

[0097] The start time point corresponding to the first period is aligned / same as the time point at which data transmission on the first link is completed.

[0098] Also, after completing data transmission on the first link, the first non-access point station performs CCA detection on the second link during a first period, the start time corresponding to the first period being earlier than the time at which the first non-access point station receives a Block Ack corresponding to the data on the first link.

[0099] It can be understood that "aligned" in this embodiment of the present application may mean time synchronization. For example, the start time of transmission is aligned (i.e., the same) and / or the end time of transmission is aligned (i.e., the same). Also, "aligned," "synchronized," "simultaneous," and "same time" in the embodiment of the present application do not mean exactly the same in the strict sense. In actual implementation, due to factors such as different PPDU transmission parameters, different access times, and transceiver processing capabilities on the two links, "aligned," "synchronized," and "simultaneous" here allow for a small offset, for example, not exceeding the time of a short inter-frame space (SIFS).

[0100] The first period corresponds to a countdown timer. When data transmission for the first link is completed, the first non-AP station starts the countdown timer. For example, as shown in Figure 9, the "first period" starts when transmission of the UL PPDU for link 1 is completed.

[0101] Optionally, the start time corresponding to the first period may be set as the start time corresponding to a medium sync delay timer (for details about the medium sync delay timer, see the description of the medium sync delay timer in 802.11-20 / 1009r1), and the end time corresponding to the first period may be set as the end time corresponding to the medium sync delay timer. In other words, it can be understood that the first non-access point station starts the medium sync delay timer based on the time when data transmission of the first link is completed.

[0102] Alternatively, the start time corresponding to the first time period can be set by the second multilink device or the first access point of the second multilink device. For example, the second multilink device can set the same or different start time points corresponding to the first time period for the first link and the second link. Furthermore, the first access point operates on the second link.

[0103] 802: If the CCA detection fails on the second link, the first non-access point station performs channel contention on the second link based on a second time period.

[0104] The start of the second period is aligned with / same as the end of CCA. The start of CCA detection is aligned with / same as the completion of data transmission on the first link. Alternatively, the start of CCA detection is aligned with / same as the reception of a Block ACK corresponding to data on the first link. Note that if the first non-AP station performs CCA detection on the second link before the start of the second period, CCA detection fails. Alternatively, if the first non-AP station performs CCA detection on the second link after the start of the second period, CCA detection is successful. The first non-AP station is, for example, Non-AP STA2 in FIG. 9. Failed CCA detection indicates a CCA Busy state for Link 2 in FIG. 9, which continues until the "second period" in FIG. 9. Successful CCA detection indicates the state after CCA Busy for Link 2 in FIG. 9 ends. In this case, the state can be understood as non-CCA Busy, or CCA Idle. The "second period" begins with the switch from CCA Busy to CCA Idle.

[0105] The second period can be understood to be the extended interframe space (EIFS) time, which can be aSIFSTime+AckTxTime+aSIFSTime, where aSIFSTime denotes the short interframe space (SIFS) time and AckTxTime denotes the transmission time of an acknowledgement (ACK) frame.

[0106] The minimum value of the second period may be aSIFSTime+AckTxTime+aSIFSTime.

[0107] It can be seen that if CCA detection is successful on the second link, channel contention can be performed on the second link in accordance with 802.11-20 / 1009r1. Here, the "in accordance with 802.11-20 / 1009r1" solution refers to the solution described above in Figure 7. The solution in Figure 7 differs from the solution in Figure 9. In the solution shown in Figure 9, channel contention, i.e., Non-AP STA2 backoff shown in Figure 9, can be performed only after the "second period." It is clear that the possibility of collision can be reduced by following the solution in Figure 9.

[0108] It is noted that in this application, the channel contention running on the second link may include the following: the first non-access point station performs channel contention on the second link according to a carrier sense multiple access with collision avoidance (CSMA / CA) mechanism or an enhanced distributed channel access (EDCA) mechanism, which is not limited here.

[0109] To allow access points and non-access point stations to access the wireless medium without colliding with each other, 802.11 uses the CSMA / CA mechanism. This mechanism is also called the distributed coordination function (DCF). Specifically, the CSMA / CA mechanism is as follows: Before transmitting data, non-access point stations must perform clear channel assessment (CCA) on the wireless medium. If the wireless medium is idle for a certain period of time (e.g., distributed inter-frame space (DIFS)), non-access point stations may initiate a random backoff procedure. If the wireless medium is busy for a certain period of time, non-access point stations must wait until the wireless medium changes to an idle state and remains idle for a certain period of time (e.g., DIFS) before initiating the random backoff procedure. After the random backoff procedure is completed, non-access point stations can perform frame exchange. The backoff time of the random backoff procedure is equal to the product of the random backoff value and the slot time. The random backoff value is a randomly selected value from the uniformly distributed contention window [0, CW]. The backoff time in the random backoff procedure can be understood to be equal to the initial value of the backoff timer in the channel contention.

[0110] Optionally, the contention window (CW) in the CSMA / CA mechanism has multiple values. When a non-AP station first attempts to contend for the channel (Initial Attempt), the CW value is the minimum value, i.e., CWmin. When each transmission fails (e.g., a collision occurs), a retransmission must be performed and channel contention will begin again. The CW value gradually increases until it reaches the maximum CW value, i.e., CWmax. After successful data transmission or transmission, the CW value is reset to CWmin.

[0111] The EDCA mechanism is an extension of DCF, allowing services of different access classes to have different EDCA parameter sets. The EDCA parameter set includes parameters such as CWmin, CWmax, and Arbitration Inter-Frame Space (AIFS). The EDCA parameters for different access classes are shown in Table 2. AC_VO indicates that the access class is a voice stream, AC_VI indicates that the access class is a video stream, AC_BE indicates that the access class is a best effort stream, and AC_BK indicates that the access class is a background stream. Table 2: EDCA parameters for different access classes [Table 2]

[0112] For a service of a certain access class, the random backoff procedure is basically the same as that of DCF. The difference is that AIFS replaces DIFS in DCF. That is, when the channel returns to idle, the random backoff procedure can be performed only after the channel has remained idle for AIFS. AIFS may be equal to the sum of the short inter-frame space (SIFS) and the product of the arbitration interframe space number (AIFS number, AIFSN) and a slot time (a Slot Time), that is, AIFS[AC] = aSIFStime + AIFSN[AC] * (a Slot Time). It can be seen that the units of both AIFS and SIFS are time units.

[0113] Optionally, performing clear channel assessment CCA detection on the second link in the first time period includes: the first non-access point station adjusts the CCA threshold to obtain an adjusted CCA threshold, the adjusted CCA threshold being less than the unadjusted CCA threshold; The first non-access point station performs CCA detection on the second link for the first time period based on the adjusted CCA threshold.

[0114] The CCA threshold includes an energy detection threshold or an intermediate energy detection threshold.

[0115] Note that in this implementation, the unadjusted energy detection threshold ranges from -82dbm to -62dbm. The unadjusted intermediate energy detection threshold may be -72dbm. Furthermore, the adjusted intermediate energy detection threshold may be a value less than -72dbm. For example, the adjusted intermediate energy detection threshold may be -82dbm.

[0116] In implementation, a method of performing CCA detection on a link based on an adjusted CCA threshold may be referred to as extended CCA. The specific name is not limited herein. In addition, in this application, CCA also includes extended CCA and CCA other than extended CCA. For example, CCA other than extended CCA is a method of performing CCA detection on a link based on an unadjusted energy detection threshold or an unadjusted intermediate energy detection threshold. The fact that the first non-access point station may perform CCA detection on the second link in a first time period may be understood to include the following: the first non-access point station performs extended CCA detection or CCA detection other than extended CCA detection on the second link in the first time period. If extended CCA detection or CCA detection other than extended CCA detection on the second link fails, the first non-access point station may perform channel contention on the second link based on a second time period.

[0117] Those skilled in the art will understand that the above description of "CCA detection failed" includes the following: the detected signal strength is greater than the aforementioned CCA threshold. In this case, the status is recorded as CCA Busy. The aforementioned CCA threshold is, for example, the energy detection (CCA-ED) threshold or the midamble energy detection (midamble-ED) threshold. Similarly, "CCA detection is successful" means that the detected signal strength is not greater than the aforementioned CCA threshold. In this case, the status is recorded as CCA Idle. For details, please refer to the related rules of IEEE Std 802.11-2016, 19.3.19.5.1 CCA-Energy Detect (CCA-ED).

[0118] The CCA-ED shall detect a channel busy condition when the received signal strength exceeds the CCA-ED threshold given by the dot11OFDMEDThreshold for the primary 20 MHz channel and the dot11OFDMEDThreshold for the secondary 20 MHz channel, if present. The CCA-ED threshold for operating classes requiring CCA-ED shall be in accordance with the criteria in D.2.5. (The CCA-ED shall detect a channel busy condition when the received signal strength exceeds the CCA-ED threshold given by the dot11OFDMEDThreshold for the primary 20 MHz channel and the dot11OFDMEDThreshold for the secondary 20 MHz channel, if present. The CCA-ED threshold for operating classes requiring CCA-ED shall be in accordance with the criteria in D.2.5.)

[0119] Optionally, the channel contention being performed on the second link based on the second time period includes the following: if the end time corresponding to the second time period is earlier than the end time corresponding to the first time period, the first non-access point station performs channel contention on the second link after the end time corresponding to the second time period. In the solution described in FIG. 9, the above description that "if CCA detection fails on the second link, the first non-access point station performs channel contention on the second link based on the second time period" means the following: after the first non-access point station (Non-AP STA2 in FIG. 9) detects that it has switched from CCA Busy to non-CCA Busy (CCA Idle), the first non-access point station starts performing backoff (Non-AP STA2 backoff in FIG. 9) after the second time period (the content of FIG. 9 corresponds to the above description that "the end time corresponding to the second time period is earlier than the end time corresponding to the first time period"). This is different from the solution in FIG. 7. 7, after detecting that CCA Busy has switched to non-CCA Busy (CCA Idle), the first non-access point station (Non-AP STA2 in FIG. 7) may immediately start backoff. If the end point corresponding to the second time period is later than the end point corresponding to the first time period, the first non-access point station performs channel contention on the second link after the end point corresponding to the first time period or after the end point corresponding to the second time period. The above description that "in the solution described in FIG. 10, if CCA detection fails on the second link, the first non-access point station performs channel contention on the second link based on the second period" means the following: after detecting that the first non-access point station (Non-AP STA2 in FIG. 10) has switched from CCA Busy to non-CCA Busy (CCA Idle), the first non-access point station (Non-AP STA2 in FIG. 10) may start performing backoff (Non-AP STA2 backoff in FIG. 10) only at one of two points: the end of the first period and the end of the second period. This is different from the solution in FIG. 7.In the solution of FIG. 7, after detecting that CCA Busy has switched to non-CCA Busy (CCA Idle), the first non-access point station (Non-AP STA2 in FIG. 7) may immediately start backoff.

[0120] If the end point corresponding to the second time period is earlier than the end point corresponding to the first time period, the first non-access point station may start backoff at the end point corresponding to the second time period. If the end point corresponding to the second time period is later than the end point corresponding to the first time period, the first non-access point station may start backoff at the end point corresponding to the first time period, or may start backoff at the end point corresponding to the second time period.

[0121] 8 is merely a procedure of the channel contention method provided in this embodiment of the present application, and it can be understood that the channel contention method of the present application may alternatively be implemented with another procedure. The following briefly describes the time-series procedure of the channel contention method of the present application with reference to some specific examples. The following specific examples are merely examples for ease of understanding. In actual applications, the time-series procedure of the channel contention method of the present application may be longer or shorter than the procedure of the following specific examples.

[0122] For ease of explanation, in the following specific example, a first multilink device (e.g., Non-AP MLD) includes Non-AP STA1 and Non-AP STA2. The first multilink device does not include Non-AP3. Non-AP3 may be a single device or may be subordinate to another Non-AP MLD. Non-AP STA1 operates on link 1, and Non-AP STA2 and Non-AP STA3 operate on link 2. A second multilink device (e.g., AP MLD) includes AP1 and AP2. The second multilink device does not include AP3. AP3 may be a single device or may be subordinate to another AP MLD. AP1 operates on link 1, and AP2 and AP3 operate on link 2. The first multilink device does not support STR, and the second multilink device does support STR.

[0123] For example, FIG. 9 is a timeline schematic diagram of a channel contention method according to an embodiment of the present application. As shown in FIG. 9, non-AP STA1 transmits an uplink PPDU to AP1 on Link 1. Because the frequency interval between the frequency bands of Link 1 and Link 2 is small, channel interference may affect CCA on Link 2 when transmitting data on Link 1. Therefore, channel information on Link 2 cannot be monitored. That is, Link 2 is in a blind period. The blind period is the blindness for non-AP STA 2 shown in FIG. 9. In the embodiment shown in FIG. 9, when non-AP STA2 is in the blind period on Link 2, AP3 transmits a DL PPDU to non-AP STA3 on Link 2. In this case, non-AP STA2 cannot detect the start of the DL PPDU.

[0124] As shown in FIG. 9, the transmission time of the uplink PPDU on Link 1 is aligned / same as the start time of the blind period of Link 2, and the end time of the uplink PPDU on Link 1 is aligned / same as the end time of the blind period of Link 2. Therefore, after the transmission of the uplink PPDU on Link 1 is completed, AP1 may send a Block ACK to Non-AP STA1 on Link 1. Also, after the transmission of the uplink PPDU on Link 1 is completed, Link 2 is not in the blind period. That is, the channel information of Link 2 can be monitored. After the transmission of the uplink PPDU on Link 1 is completed, Non-AP STA2 may start a countdown based on the start time corresponding to the first period. That is, Non-AP STA2 starts a countdown timer. The period corresponding to the countdown timer is the first period. During the first period, Non-AP STA2 may perform CCA detection on Link 2.

[0125] Furthermore, when CCA detection is performed on Link 2, it fails because AP3 is transmitting a downlink PPDU to Non-AP STA3 on Link 2. "CCA detection fails" indicates "CCA Busy" in FIG. 9. It can be seen that CCA detection on Link 2 is successful after the downlink PPDU transmission is completed. "CCA detection is successful" indicates that "CCA Busy" ends and "CCA Idle" begins in FIG. 9. As shown in FIG. 9, it can be seen that the end point of the downlink PPDU transmission is the same as / aligns with the time when CCA detection on Link 2 is successful, and the start point corresponding to the second period is the same as / aligns with the time when CCA detection on Link 2 is successful. Furthermore, during the second period, a Block ACK BA corresponding to the downlink PPDU is transmitted on Link 2. If the time point at which transmission of the Block Ack corresponding to the downlink PPDU of Link 2 is completed is earlier than the end time of the second period, and the end time of the second period is earlier than the end time of the first period, Non-AP STA2 starts backoff at the end time of the second period, thereby avoiding collisions and interference between frames.

[0126] In another example, FIG. 10 is a timeline schematic diagram of a channel contention method according to an embodiment of the present application. As shown in FIG. 10, non-AP STA1 transmits an uplink PPDU to AP1 over Link 1. Because the frequency spacing between the frequency bands of Link 1 and Link 2 is small, channel interference may affect CCA detection on Link 2 when transmitting data over Link 1. Therefore, channel information for Link 2 cannot be monitored. That is, Link 2 is in a blind period. The blind period is the blindness for non-AP STA 2 shown in FIG. 10. In the embodiment shown in FIG. 10, when non-AP STA2 is in the blind period on Link 2, AP3 transmits a DL PPDU to non-AP STA3 over Link 2. In this case, non-AP STA2 cannot detect the start of the DL PPDU.

[0127] As shown in FIG. 10, the transmission time of the uplink PPDU on Link 1 is aligned / same as the start time of the blind period of Link 2, and the end time of the uplink PPDU on Link 1 is aligned / same as the end time of the blind period of Link 2. Therefore, after the transmission of the uplink PPDU on Link 1 is completed, AP1 may send a Block ACK to Non-AP STA1 on Link 1. Also, after the transmission of the uplink PPDU on Link 1 is completed, Link 2 is not in the blind period. That is, the channel information of Link 2 can be monitored. After the transmission of the uplink PPDU on Link 1 is completed, Non-AP STA2 can start a countdown based on the start time corresponding to the first period. That is, Non-AP STA2 starts a countdown timer. The period corresponding to the countdown timer is the first period. During the first period, Non-AP STA2 may perform CCA detection on Link 2.

[0128] Furthermore, when CCA detection is performed on Link 2, it fails because AP3 is transmitting a downlink PPDU to Non-AP STA3 on Link 2. "CCA detection fails" indicates "CCA Busy" in Figure 10. It can be seen that CCA detection on Link 2 is successful after the downlink PPDU transmission is completed. "CCA detection is successful" indicates that "CCA Busy" ends and "CCA Idle" begins in Figure 10. As shown in Figure 10, it can be seen that the end point of the downlink PPDU transmission is the same as / aligns with the time when CCA detection on Link 2 is successful, and the start point corresponding to the second period is the same as / aligns with the time when CCA detection on Link 2 is successful. Furthermore, during the second period, a Block ACK corresponding to the downlink PPDU is transmitted on Link 2. If the completion of transmission of the Block Ack corresponding to the downlink PPDU of Link 2 is earlier than the end point of the second period and the end point of the second period is later than the end point of the first period, Non-AP STA2 starts backoff at the end point of the second period or the end point of the first period, thereby avoiding collisions and interference between frames.

[0129] 11 is a schematic diagram of another channel contention method according to an embodiment of the present application. As shown in FIG. 11, the another channel contention method provided in this embodiment of the present application includes, but is not limited to, the following steps:

[0130] 1101: A first non-access point station updates a network allocation vector NAV based on a radio frame, and obtains an updated NAV.

[0131] The radio frame is a radio frame transmitted to a second non-access point station on the second link when data is being transmitted on the first link or when a Block Ack corresponding to the data is being transmitted on the first link. The second non-access point station is a non-access point station other than the first non-access point station in the first multi-link device. The radio frame is a radio frame received when the second link is in a blind period, and it can be understood that the first non-access point station can update its network allocation vector (NAV) based on the radio frame and obtain an updated NAV.

[0132] For the data, please refer to the data description in step 801 in Figure 8. The details will not be described again here.

[0133] The radio frames may include, but are not limited to, Block Ack, data frames, management frames, and trigger frames, for example.

[0134] Furthermore, the first non-access point station updates the network allocation vector NAV based on the duration information transmitted in the radio frame to obtain an updated NAV. Before updating, the duration information is greater than the NAV. That is, the updated NAV is greater than the NAV. It can be seen that the radio frame may include a duration field. The duration field indicates the duration information. The first non-access point station updates the network allocation vector NAV based on the duration information included in the radio frame to obtain an updated NAV. A specific updating method is not limited in this application.

[0135] For example, when a non-access point station other than the first non-access point station and the second non-access point station in the first multi-link device transmits a PPDU on the second link, the first non-access point station can update its network allocation vector NAV based on the Block Ack transmitted in the PPDU to obtain an updated NAV. The Block Ack transmits duration information. That is, the first non-access point station updates its network allocation vector NAV based on the duration information transmitted in the Block Ack to obtain an updated NAV.

[0136] 1102: The first non-access point station performs channel contention on the second link based on the updated NAV.

[0137] Optionally, the channel contention running on the second link based on the updated NAV includes: If the updated NAV is less than the time when data transmission on the first link is completed or when a Block ACK is received on the first link, the first non-access point station performs CCA detection on the second link during the first period; If the CCA detection fails on the second link, the first non-access point station performs channel contention on the second link based on a second time period; or If the updated NAV is greater than the value at which data transmission on the first link is completed or a Block ACK is received on the first link, the first non-access point station performs channel contention on the second link when the updated NAV backs off to 0.

[0138] For the first period, refer to the description of the first period in step 801 in Fig. 8. Details will not be described again here. For the second period, refer to the description of the second period in step 802 in Fig. 8. Details will not be described again here. Also, for information about the first non-access point station performing channel contention on the second link based on the second period if CCA detection fails, refer to the related description of step 802 in Fig. 8. Details will not be described again here.

[0139] Note that if the updated NAV is greater than the value at the time data transmission on the first link is completed or a Block ACK is received on the first link, the first non-access point station starts backoff based on the updated NAV. Regardless of whether data transmission on the first link is completed before the updated NAV backoff to 0, the first non-access point station may perform channel contention on the second link when the updated NAV backoff to 0. Furthermore, when the updated NAV backoff to 0, the first non-access point station performs CCA detection other than extended CCA on the second link. If CCA detection on the second link is successful, the first non-access point station can perform frame exchange on the second link.

[0140] It can be understood that the time when the updated NAV backs off to 0 can be earlier than or later than the time when data transmission on the first link is completed. This is not limited here. Furthermore, when data transmission on the first link is completed, the first non-access point station starts a countdown timer. The period corresponding to the countdown timer is the first period.

[0141] Optionally, when data transmission on the first link is completed, the first non-access point station may start a countdown timer regardless of whether the updated NAV backs off to 0. The period corresponding to the countdown timer is a first period.

[0142] Also, if the time when the updated NAV backs off to 0 may be later than the time when data transmission on the first link is completed, the first non-access point station may perform channel contention in the first period. Furthermore, once the updated NAV backs off to 0, the first non-access point station may perform CCA detection other than extended CCA on the second link in the first period. If the CCA detection is successful, the first non-access point station can perform frame exchange on the second link.

[0143] 11 is merely a procedure of the channel contention method provided in this embodiment of the present application, and it can be understood that the channel contention method of the present application may alternatively be implemented with another procedure. The following briefly describes the time-series procedure of the channel contention method of the present application with reference to several specific examples. The following specific examples are merely examples for ease of understanding. In actual applications, the time-series procedure of the channel contention method of the present application may be longer or shorter than the procedure of the following specific examples.

[0144] For ease of explanation, in the following specific example, a first multilink device (e.g., Non-AP MLD) includes Non-AP STA1 and Non-AP STA2. The first multilink device does not include Non-AP3. Non-AP3 may be a single device or may be subordinate to another Non-AP MLD. Non-AP STA1 operates on link 1, and Non-AP STA2 and Non-AP STA3 operate on link 2. A second multilink device (e.g., AP MLD) includes AP1 and AP2. The second multilink device does not include AP3. AP3 may be a single device or may be subordinate to another AP MLD. AP1 operates on link 1, and AP2 and AP3 operate on link 2. The first multilink device does not support STR, and the second multilink device does support STR.

[0145] For example, FIG. 12 is a timeline schematic diagram of a channel contention method according to an embodiment of the present application. As shown in FIG. 12, Non-AP STA1 transmits PPDU1 to AP1 on Link 1. Because the frequency interval between the frequency bands of Link 1 and Link 2 is small, channel interference may affect CCA on Link 2 when transmitting data on Link 1. Therefore, the channel information of Link 2 cannot be monitored. That is, Link 2 is in a blind period. As shown in FIG. 12, the transmission time of PPDU1 on Link 1 is aligned / same as the start time of the blind period of Link 2, and the end time of PPDU1 on Link 1 is aligned / same as the end time of the blind period of Link 2. Therefore, after completing the transmission of PPDU1 on Link 1, AP1 may send Block ACK1 to Non-AP STA1 on Link 1. Furthermore, after completing the transmission of PPDU1 on Link 1, Link 2 is not in a blind period. That is, the channel information of Link 2 can be monitored. It can be understood that after completing the transmission of PPDU1 on Link 1, Non-AP STA2 can start a countdown based on a start point corresponding to the first period. That is, Non-AP STA2 starts a countdown timer. The period corresponding to the countdown timer is the first period.

[0146] Furthermore, when Link 2 is in the blind period, AP 3 transmits PPDU2 to Non-AP STA 3 on Link 2. As shown in FIG. 12 , the transmission time of PPDU2 on Link 2 is later than the start time of the blind period of Link 2, and the end time of PPDU2 on Link 2 is earlier than the end time of the blind period of Link 2. That is, when Link 2 is in the blind period, PPDU2 is received by Non-AP STA 3. Furthermore, when Non-AP STA 3 receives PPDU2, Non-AP STA 2 may update its NAV based on PPDU2. Optionally, the end time of reception of PPDU2 on Link 2 may be earlier or later than the end time of the blind period of Link 2. This is not a limitation here.

[0147] After the transmission of PPDU2 is completed, it is determined that CCA detection on link 2 is successful. As shown in FIG. 12, the end point of the transmission of PPDU2 coincides with the successful CCA detection on link 2. Furthermore, after receiving PPDU2, non-AP STA3 may transmit Block ACK2 to AP3 on the second link. Non-AP STA2 re-updates its NAV based on Block ACK2. Non-AP STA2 may then perform backoff based on the re-updated NAV. When the re-updated NAV backoffs to 0, non-AP STA2 performs CCA detection other than extended CCA on the second link. If CCA detection is successful, the first non-AP station can perform frame exchange on the second link.

[0148] 12, when data transmission on the first link is completed, the first non-AP station starts a countdown based on the start time corresponding to the first period, regardless of whether the re-updated NAV backs off to zero. That is, when data transmission on the first link is completed, the first non-AP station starts a countdown timer. The period corresponding to the countdown timer is the first period.

[0149] It can be seen that the end point of the NAV corresponding to PPDU2 is earlier than the end point of the NAV corresponding to Block ACK2. Optionally, if another PPDU is received from AP3 after Block ACK2, Non-AP STA2 can further update its NAV based on the other PPDU.

[0150] For example, FIG. 13 is a timeline schematic diagram of a channel contention method according to an embodiment of the present application. As shown in FIG. 13, Non-AP STA1 transmits PPDU1 to AP1 on Link 1. Because the frequency interval between the frequency bands of Link 1 and Link 2 is small, channel interference may affect CCA on Link 2 when transmitting data on Link 1. Therefore, the channel information of Link 2 cannot be monitored. That is, Link 2 is in a blind period. As shown in FIG. 13, the transmission time of PPDU1 on Link 1 is aligned / same as the start time of the blind period of Link 2, and the end time of PPDU1 on Link 1 is aligned / same as the end time of the blind period of Link 2. Therefore, after completing the transmission of PPDU1 on Link 1, AP1 may transmit Block ACK1 to Non-AP STA1 on Link 1. Furthermore, after completing the transmission of PPDU1 on Link 1, Link 2 is not in a blind period. That is, the channel information of Link 2 can be monitored.

[0151] Furthermore, AP3 transmits PPDU2 to non-AP STA3 on link 2. It can be seen that the transmission time of PPDU2 is later than the start time of the blind period of link 2, and the reception time of PPDU2 is earlier than the end time of the blind period of link 2. In other words, PPDU2 is a PPDU received when link 2 is in the blind period. Furthermore, when non-AP STA3 receives PPDU2, non-AP STA2 updates its NAV based on PPDU2. Furthermore, after receiving PPDU2, non-AP STA3 may transmit Block ACK2 to AP3 on link 2. Non-AP STA2 may then re-update its NAV based on Block ACK2. Non-AP STA2 may then perform backoff based on the re-updated NAV. When the re-updated NAV backoffs to 0, non-AP STA2 performs CCA detection other than extended CCA on link 2. If CCA detection is successful, the first non-AP station can perform frame exchange on link 2. Optionally, the end time of receiving PPDU2 on Link 2 may be earlier or later than the end time of the blind period of Link 2. This is not limited here.

[0152] 13, when data transmission on the first link is completed, the first non-AP station starts a countdown based on the start point corresponding to the first period, regardless of whether the re-updated NAV backs off to zero. That is, when data transmission on the first link is completed, the first non-AP station starts a countdown timer. The period corresponding to the countdown timer is the first period.

[0153] It can be seen that the end point of the NAV corresponding to PPDU2 is the same as the end point of the NAV corresponding to Block ACK2. Optionally, if another PPDU is received from AP3 after Block ACK2, Non-AP STA2 can further update its NAV based on the other PPDU.

[0154] According to standards known in the art, the CCA detection described in the above implementation includes detection on at least the primary 20 MHz channel occupied by the PPDU. For more information, see sections such as IEEE Std 802.11-2016, 10.22.2.5. If both the STA and the BSS of which the STA is a member support multiple channel widths, the EDCA TXOP is acquired based solely on activity on the primary channel. In this subcloud, "idle medium" refers to the "idle primary channel." Similarly, "busy medium" refers to the "busy primary channel." Once an EDCA TXOP is acquired according to this subcloud, further constraints defined in 11.16.9 and 10.22.3 may limit the transmission width during the TXOP or deny channel access based on the CCA status of the secondary channel, secondary 40 MHz channel, or secondary 80 MHz channel. (If both the STA and the BSS of which it is a member support multiple channel widths, the EDCA TXOP is acquired based solely on activity on the primary channel. In this subcloud, "idle medium" means "idle primary channel." Similarly, "busy medium" means "busy primary channel." Once an EDCA TXOP is acquired according to this subcloud, further constraints defined in 11.16.9 and 10.22.3 may limit the transmission width during the TXOP or deny channel access based on the CCA status of the secondary channel, secondary 40 MHz channel, or secondary 80 MHz channel.)

[0155] The above content has detailedly described the method provided in the present application. In order to better implement the aforementioned solution in the embodiments of the present application, the embodiments of the present application further provide a corresponding device or apparatus.

[0156] FIG. 14 is a schematic diagram of the structure of a communication device according to an embodiment of the present application. As shown in FIG. 14, the communication device 1400 may be the first multi-link device in the above embodiments, or a chip or processing system within the first multi-link device, and may implement the methods and functions of any of the above embodiments. Depending on the level of integration, the communication device 1400 may include one or more of the components shown in FIG. 14. The components shown in FIG. 14 may include at least one processor 1401, memory 1402, transceiver 1403, and communication bus 1404. The processor, transceiver, memory, etc. are connected via a bus. The specific connections between the aforementioned components are not limited to this embodiment of the present application.

[0157] The components of the communication device 1400 will now be specifically described with reference to FIG.

[0158] Processor 1401 is the control center of communication device 1400 and may refer to a single processor or multiple processing elements. For example, processor 1401 may be a central processing unit (CPU) or an application specific integrated circuit (ASIC), or may be configured as one or more integrated circuits implementing embodiments of the present application, such as one or more microprocessors (digital signal processors, DSPs) or one or more field programmable gate arrays (FPGAs). Processor 1401 may implement various functions of the communication device by executing or running software programs stored in memory 1402 and accessing data stored in memory 1402. During a particular implementation, in an embodiment, processor 1401 may include one or more CPUs, such as CPU0 and CPU1 in FIG. 14 .

[0159] During particular implementation, in an embodiment, communications device 1400 may include multiple processors, such as processor 1401 and processor 1405 of FIG. 14. Each of the processors may be a single-core processor (single-CPU) or a multi-core processor (multi-CPU). A processor, as used herein, may be one or more communications devices, circuits, and / or processing cores configured to process data (e.g., computer program instructions).

[0160] Memory 1402 may be, but is not limited to, read-only memory (ROM), another type of static storage and communication device capable of storing static information and instructions, random access memory (RAM), or another type of dynamic storage and communication device capable of storing information and instructions, or may be electrically erasable programmable read-only memory (EEPROM), compact disc read-only memory (CD-ROM), or another compact disc storage device, optical disc storage device (including compact disc, laser disc, optical disc, digital versatile disc, Blu-ray disc, etc.), disc storage medium or another disc storage and communication device, or any other medium usable to carry or store program code expected in the form of instructions or data structures and accessible by a computer. Memory 1402 may exist independently and be connected to processor 1401 via communication bus 1404. Alternatively, memory 1402 may be integrated into processor 1401. The memory 1402 is configured to store software programs for executing the solution of the present application, and the processor 1401 controls the execution.

[0161] The transceiver 1403 is configured to communicate with another device (e.g., a second multilink device). Of course, the transceiver 1403 can be further configured to communicate with a communication network. The communication network can be, for example, an Ethernet, a radio access network (RAN), or a wireless local area network. The transceiver 1403 can include a receiving unit for implementing a receiving function and a transmitting unit for implementing a transmitting function.

[0162] The communication bus 1404 may be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, an Extended Industry Standard Architecture (EISA) bus, etc. A bus may be categorized as an address bus, a data bus, a control bus, etc. For ease of presentation, only one thick line is used to represent a bus in FIG. 14, but this does not mean that there is only one bus or only one type of bus.

[0163] In an example, the communication device 1400 may be an entire device, and the communication device may include a processor 1401, a memory 1402, a transceiver 1403, and a communication bus 1404. Optionally, other components, such as a display screen, a user interface, or a signal detector, may also be included. Optionally, the communication device 1400 may be a first multilink device and may be configured to implement the methods and functions associated with the first multilink device of the above-described embodiments. For example, the memory may store instructions, and when the processor invokes the instructions, the above-described methods and functions are implemented. For example, the processor may be configured to generate a signal or frame, and the transceiver may be configured to transmit the signal or frame. For example, the processor may be configured to perform steps S141, S201, etc., and the transceiver may be configured to perform steps S142, S202, S207, etc.

[0164] In another example, the communications device 1500 may be a chip system or processing system within the first multi-link device, such that a device incorporating the chip system or processing system implements the methods and functions of any of the above-described embodiments. In this case, the communications device 1400 may include some of the components shown in FIG. 14 . For example, the communications device 1400 may include a processor. The processor is coupled to a memory and is capable of accessing and executing instructions within the memory, such that a device incorporating or having the chip system or processing system implemented implements the methods and functions of the above-described embodiments. Optionally, the memory may be a component within the chip system or processing system, or may be a component external to the chip system or processing system. In the example, the chip system or processing system is installed in the first multi-link device, such that the first multi-link device can implement the corresponding methods and functions of the above-described embodiments.

[0165] The chip system or processing system may support communication according to 802.11 series protocols, such as 802.11be, 802.11ax, and 802.11ac. The chip system may be installed in various devices that support WLAN transmission scenarios. The devices for WLAN transmission scenarios are described in the specification of this application. Details will not be described again here.

[0166] In this embodiment of the present application, the first multi-link device or the second multi-link device may be divided into functional modules based on the above-mentioned method examples. For example, the functional modules may be obtained through division based on corresponding functions, 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 function module. It should be noted that in this embodiment of the present application, the division into modules is an example and is merely a logical functional division. In actual implementation, other division methods may be used.

[0167] When an integrated unit is used, Figure 15 is a schematic diagram of another structure of a communication device according to an embodiment of the present application. As shown in Figure 15, the communication device 1500 may be a chip or a processing system within a multi-link device. In the above method embodiment, the communication device 1500 may perform the operations of the first multi-link device. The communication device 1500 includes a processing unit 1501.

[0168] In the example, the communication device 1500 is a non-access point station in a first multilink device.

[0169] The processing unit 1501 may be configured to control and manage the operation of the communication device 1500. For example, the detection of CCA is performed on the second link during the first time period. Optionally, if the communication device 1500 includes a storage unit, the processing unit 1501 may further execute programs or instructions stored in the storage unit, such that the communication device 1500 can implement the methods and functions of any of the above embodiments.

[0170] For example, the processing unit 1501 may be configured to perform, for example, step 801 of Fig. 8, or step 801 of Fig. 8 and / or other processes of the techniques described herein. All relevant contents of the steps in the foregoing method embodiments may be cited in the functional descriptions of the corresponding functional modules. The details will not be described again here.

[0171] For example, the communication device 1500 may be the communication device shown in FIG. 14. The processing unit 1501 may be the processor 1401 of FIG. 14. Furthermore, the communication device 1500 may include a transceiver unit. The transceiver unit may be the transceiver 1403 of FIG. 14. Optionally, the communication device 1500 may further include a memory. The memory is configured to store corresponding program code and data for the communication device 1500 to perform any of the above-described channel contention methods between multi-link devices. For a functional description of corresponding components of the communication device 1500, reference may be made to the description of all relevant contents of the components in FIG. 14. Details will not be described again here.

[0172] For example, the communication device 1500 may alternatively be a chip or a processor. The processing unit 1501 may be a processing circuit within the chip or processor. The transceiver unit may be an input / output circuit within the chip or processor. The input / output circuit is an interface for intercommunication or data exchange between the chip or processor and another coupled component. Signals or data information or program instructions may be input to the chip or processor for processing, and the processed data or processed signals may be output to another coupled component, such that the first multilink device in which the chip or processor is installed is controlled to implement a function.

[0173] An embodiment of the present application further provides a computer-readable storage medium, which stores computer program code, and when the processor executes the computer program code, the electronic device performs the method in any of the above embodiments of FIG.

[0174] An embodiment of the present application further provides a computer program product, which, when executed on a computer, enables the computer to perform the method in any of the above embodiments of FIGS.

[0175] An embodiment of the present application further provides a communication device. The device may exist in the product form of a chip. The structure of the device includes a processor and an interface circuit. The processor is configured to communicate with another device through the interface circuit, so that the device performs any of the methods of the above-mentioned embodiments of Figures 8 and 11.

[0176] An embodiment of the present application further provides a communication system including a first multi-link device and a second multi-link device, wherein the first multi-link device and the second multi-link device are capable of performing the method of any of the above-described embodiments of Figures 8 and 11.

[0177] The method or algorithm steps described in connection with the subject matter disclosed 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, a removable hard disk, a compact disk read-only memory (CD-ROM), or any other form of storage medium well known in the art. For example, the storage medium may be coupled to the processor such that the processor can read information from or write information to the storage medium. Of course, the storage medium may be components 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 separate components in the core network interface device.

[0178] Those skilled in the art should recognize that, in one or more of the foregoing examples, the functions described herein may be implemented by hardware, software, firmware, or any combination thereof. If the functions are implemented by software, they may be stored on or transmitted as one or more instructions or code on a computer-readable medium. Computer-readable media may include computer-readable storage media and communication media, and further include any medium that facilitates the transmission of a computer program from one place to another. Storage media may be any available medium that can be accessed by a general-purpose or special-purpose computer.

[0179] The above specific implementations further describe the objectives, technical solutions, and beneficial effects 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 protection scope of the present application. Any modifications, equivalent replacements, or improvements made based on the technical solutions of the present application should be encompassed within the protection scope of the present application.

Claims

1. 1. A channel contention method, the method comprising: performing clear channel assessment (CCA) detection on a second link within a first time period after data transmission on the first link is completed; if a received signal strength exceeds a CCA-ED threshold within the first time period and a start of a physical layer protocol data unit (PPDU) is not detected, performing channel contention on the second link after a second time period from when the received signal strength falls below the CCA-ED threshold; A method comprising:

2. 2. The method of claim 1, wherein the CCA threshold is −82 dbm, −72 dbm, or −62 dbm.

3. The method of claim 1 or 2, wherein the second period is an extended inter-frame space (EIFS) time.

4. The method according to any one of claims 1 to 3, wherein a start point corresponding to the first period is the same as a point at which the data transmission on the first link is completed.

5. A communication device, the communication device comprising: a processing unit configured to perform clear channel assessment (CCA) detection on the second link within a first time period after data transmission on the first link is completed; the processing unit is further configured to, if a received signal strength exceeds a CCA-ED threshold within the first period and a start of a physical layer protocol data unit (PPDU) is not detected, perform channel contention on the second link after a second period from when the received signal strength falls below the CCA-ED threshold.

6. 6. The communication device according to claim 5, wherein the CCA threshold is −82 dbm, −72 dbm, or −62 dbm.

7. 7. The communication device according to claim 5, wherein the second period is an extended inter-frame space (EIFS) time.

8. The communication device according to claim 5, wherein a start point corresponding to the first period is the same as a point at which the data transmission on the first link is completed.

9. A communication device, a processor; a memory configured to store instructions; Including, A communications device, wherein when said processor executes said instructions, said communications device is enabled to perform the method of any one of claims 1 to 4.

10. A wireless communication system, comprising a first multi-link device, said first multi-link device comprising a communication device according to any one of claims 5 to 8.

11. A readable storage medium having stored thereon program instructions which, when executed, perform the method of any one of claims 1 to 4.

12. A computer program comprising instructions that, when executed on a computer, enable the computer to carry out the method of any one of claims 1 to 4.

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