Multi-link communication method and device

Abstract

The embodiment of the invention discloses a multi-link communication method and a related device. The method comprises the following steps: in a scene of not supporting simultaneous multi-link transceiving, a multi-link device firstly sends a first physical layer protocol data unit (PPDU) on a first link; and sending a second PPDU on the second link through the contention channel, wherein the end time of the second PPDU is not later than the end time of the first PPDU. According to the method, the fairness of multi-link access is guaranteed, and the idle rate of multiple links can be reduced.

Description

[0001] This application is a divisional application. The application number of the original application is 201910629773.9, and the original application date is July 12, 2019. The entire content of the original application is incorporated into this application by reference. Technical Field

[0002] The present application relates to the field of communication technology, and in particular to a multi-link communication method, device, and system. Background Art

[0003] In order to significantly improve the service transmission rate of Wireless Local Area Networks (WLAN) systems, the Institute of Electrical and Electronics Engineers (IEEE) 802.11ax standard further adopts Orthogonal Frequency Division Multiple Access (OFDMA) technology based on the existing Orthogonal Frequency Division Multiplexing (OFDM) technology. OFDMA technology supports multiple nodes to send and receive data simultaneously, thereby achieving multi-site diversity gain. And with the further development of the new free frequency band 5925-7125MHz (called this band 6GHz), the operating frequency band of the WLAN system has expanded from 2.4GHz and 5GHz to 2.4GHz, 5GHz and 6GHz.

[0004] Devices that can operate on multiple frequency bands are called multi-link devices or multi-band devices. Multi-link devices can support multi-link communications, for example, supporting simultaneous communication on the 2.4GHz, 5GHz, and 6GHz bands. Even when the number of antennas is limited, multi-link devices can switch between different frequency bands to select the optimal band and ensure communication quality. However, ensuring fairness in communication among multi-link devices operating on multiple links, reducing link idle rates, and improving communication efficiency are crucial in systems that support multi-link communications. Summary of the Invention

[0005] The embodiments of the present application provide a multi-link communication method, apparatus, and system to ensure fairness in communication among multi-link devices operating on multiple links, reduce link idle rates, and improve communication efficiency.

[0006] In a first aspect, a multi-link communication method is provided, which is applied to a multi-link device. The multi-link device operates on multiple links, including a first link and a second link. The multi-link device does not support simultaneous transmission and reception of PPDUs on the first link and the second link. The method comprises: the multi-link device sends a first physical layer protocol data unit (PPDU) on the first link; and the multi-link device sends a second PPDU on the second link via a contention channel. The end time of the second PPDU is no later than the end time of the first PPDU, for example, the end time of the second PPDU is the same as the end time of the first PPDU. Optionally, the start time of the second PPDU is no earlier than the start time of the first PPDU, including being later than or equal to the start time of the first PPDU. The multi-link device first sends the PPDU on the first link, and then independently sends the PPDU after performing channel contention on the second link. The multi-link device independently competes for channels on the multiple links, with the link that competes for the channel first sending a message packet first, and the link that competes for the channel later sending the message packet later. This method can ensure fairness in multi-link access, reduce the idle rate of the multi-links, and improve frequency efficiency.

[0007] The multi-link device does not support simultaneous transmission and reception on the first link and the second link, including: the multi-link device does not support simultaneous transmission of physical layer protocol data units of a first bandwidth on the first link and reception of physical layer protocol data units of a second bandwidth on the second link, and / or the multi-link device does not support simultaneous reception of physical layer protocol data units of a first bandwidth on the first link and transmission of physical layer protocol data units of a second bandwidth on the second link. The "simultaneous" means that there is a non-empty temporal intersection between the PPDU of the first bandwidth and the PPDU of the second bandwidth.

[0008] In one possible design, the first PPDU includes an uplink / downlink indication, where the uplink / downlink indication is used to indicate a transmission direction of the first PPDU, where the transmission direction may be uplink or downlink. Based on the uplink / downlink indication, other devices may determine the type of the multilink device sending the first PPDU. Optionally, if the transmission direction is uplink, the multilink device sending the first PPDU is a multilink site; if the transmission direction is downlink, the multilink device sending the first PPDU is a multilink access point.

[0009] In one possible design, the first PPDU includes first TXOP duration information, which indicates the duration of the first TXOP; the second PPDU includes second TXOP duration information, which indicates the duration of the second TXOP; the duration of the first TXOP is the same as the duration of the second TXOP. That is, the second TXOP indicated in the second PPDU can be set based on the first TXOP indicated in the first PPDU. The first TXOP duration information is carried in the duration field of the physical layer preamble of the first PPDU or the MAC header of the first PPDU; the second TXOP duration information is carried in the duration field of the physical layer preamble of the second PPDU or the MAC header of the second PPDU.

[0010] A second aspect provides another multi-link communication method, applied to a multi-link device, wherein the multi-link device operates on multiple links, including a first link and a second link, and the multi-link device does not support simultaneous transmission and reception of PPDUs on the first link and the second link. The method comprises: a first multi-link device transmitting a first physical layer protocol data unit (PPDU) on the first link; after a preset time interval, the first multi-link device receiving a second PPDU on the first link from a second device in response to the first PPDU; and the first multi-link device receiving a third PPDU on the second link, sent by a third multi-link device on the second link, wherein the end time of the third PPDU is no later than the end time of the second PPDU, where "no later than" includes earlier than or equal to the end time of the second PPDU; optionally, the start time of the third PPDU is no earlier than the end time of the first PPDU, where "no earlier than" includes later than or equal to the end time of the first PPDU. Optionally, the first multi-link device and the third multi-link device belong to the same basic service set (BSS). By adopting the above method, when other multi-link devices receive the PPDU sent by the first multi-link device on the first link, they can start to seize the channel (including actions such as listening and backing off) on another link when the PPDU ends, thereby sending the PPDU. This can not only ensure the fairness of multi-link access, but also reduce the idle rate of multi-links and improve frequency efficiency.

[0011] The multi-link device does not support simultaneous transmission and reception on the first link and the second link, including: the multi-link device does not support simultaneous transmission of physical layer protocol data units of a first bandwidth on the first link and reception of physical layer protocol data units of a second bandwidth on the second link, and / or the multi-link device does not support simultaneous reception of physical layer protocol data units of a first bandwidth on the first link and transmission of physical layer protocol data units of a second bandwidth on the second link. The "simultaneous" means that there is a non-empty temporal intersection between the PPDU of the first bandwidth and the PPDU of the second bandwidth.

[0012] In one possible design, the first PPDU includes transmission duration information, which is used to indicate the transmission duration of the second PPDU; or the physical layer preamble of the second PPDU includes the transmission duration information, which is used to indicate the transmission duration of the second PPDU. Based on the transmission duration information, the third multi-link device can obtain the transmission duration of the second PPDU and thus determine the transmission duration and end time of the third PPDU based on the transmission duration of the second PPDU, thereby preventing the first multi-link device from transmitting and receiving on the first link and the second link at the same time.

[0013] In one possible design, the third PPDU includes third TXOP duration information indicating a third TXOP duration, and the third TXOP duration does not exceed the minimum value or the earliest end value of the first TXOP duration and the second duration indicated by the first TXOP duration information in the first PPDU; wherein the second duration is the transmission duration of the second PPDU, or the transmission duration of the second PPDU + SIFS + the transmission duration of the confirmation information in response to the second PPDU.

[0014] In one possible design, the first PPDU includes data information, and the second PPDU includes confirmation information; or, the first PPDU includes trigger information, and the second PPDU includes uplink data. Of course, the first PPDU may also include other information.

[0015] A third aspect provides another multi-link communication method, applied to a multi-link device operating on multiple links, the multiple links including a first link and a second link. The method comprises: a third multi-link device obtaining a first PPDU transmitted by a first multi-link device on the first link; at or after the end time of the first PPDU, the third multi-link device transmitting a third PPDU on the second link, wherein the end time of the third PPDU is no later than the end time of the second PPDU, and the second PPDU is transmitted on the first link in response to the first PPDU. "No later than" includes "no later than" or "equal to" the end time of the second PPDU. The second PPDU responds to the first PPDU transmitted by the first multi-link device on the first link. The start time of the third PPDU is no earlier than the end time of the first PPDU, and "no earlier than" includes "no earlier than" or "equal to" the end time of the first PPDU. Optionally, the third multi-link device may transmit the third PPDU via a contention channel. The first multi-link device and the third multi-link device belong to the same basic service set (BSS).

[0016] By adopting the above method, when other multi-link devices receive the PPDU sent by the first multi-link device on the first link, they can start to seize the channel (including actions such as listening and backing off) on another link when the PPDU ends, thereby sending the PPDU. This can not only ensure the fairness of multi-link access, but also reduce the idle rate of multi-links and improve frequency efficiency.

[0017] In one possible design, sending a third PPDU on the second link through the contention channel includes: sending the third PPDU on the second link through the contention channel by the third multi-link device at or after the end time of the first PPDU.

[0018] In one possible design, the first PPDU includes transmission duration information, which is used to indicate the transmission duration of the second PPDU; or the physical layer preamble of the second PPDU includes the transmission duration information, which is used to indicate the transmission duration of the second PPDU. Based on the transmission duration information, the third multi-link device can obtain the transmission duration of the second PPDU and thus determine the transmission duration and end time of the third PPDU based on the transmission duration of the second PPDU, thereby preventing the first multi-link device from transmitting and receiving on the first link and the second link at the same time.

[0019] In one possible design, the third PPDU includes third TXOP duration information indicating a third TXOP duration, and the third TXOP duration does not exceed the minimum value or the earliest end value of the first TXOP duration and the second duration indicated by the first TXOP duration information in the first PPDU; wherein the second duration is the transmission duration of the second PPDU, or the transmission duration of the second PPDU + SIFS + the transmission duration of the confirmation information in response to the second PPDU.

[0020] In one possible design, the first PPDU includes data information, and the second PPDU includes confirmation information; or, the first PPDU includes trigger information, and the second PPDU includes uplink data. Of course, the first PPDU may also include other information.

[0021] In a fourth aspect, a multi-link communication device is provided, which operates on multiple links, including a first link and a second link. The device includes: a first sending module, configured to send a first physical layer protocol data unit (PPDU) on the first link; and a second sending module, configured to send a second PPDU on the second link via a contention channel, wherein the end time of the second PPDU is no later than the end time of the first PPDU. For example, the end time of the second PPDU is the same as the end time of the first PPDU. Optionally, the start time of the second PPDU is no earlier than the start time of the first PPDU, including being later than or equal to the start time of the first PPDU. The multi-link device first sends the PPDU on the first link, and then independently sends the PPDU after performing channel contention on the second link. The multi-link device independently competes for channels on multiple links, with the link that competes for the channel first sending a message packet first, and the link that competes for the channel later sending the message packet later. This ensures fairness in multi-link access, reduces the idle rate of multiple links, and improves frequency efficiency.

[0022] In one possible design, the device further includes a first processing module and a second processing module, wherein the first processing module is configured to generate the first PPDU and the second processing module is configured to generate the second PPDU. The first processing module and the second processing module may also be one processing module.

[0023] In a fifth aspect, a multi-link communication device is provided, which operates on multiple links, the multiple links including: a first link and a second link, including:

[0024] A first transceiver module is configured to send a first physical layer protocol data unit (PPDU) on a first link;

[0025] The first transceiver module is configured to receive, by the first multi-link device, a second PPDU in response to the first PPDU from the second device on the first link after a preset time interval;

[0026] The second transceiver module is configured to receive, on a second link, a third PPDU sent by a third multi-link device on the second link, where an end time of the third PPDU is not later than an end time of the second PPDU.

[0027] In one possible design, the first transceiver module further includes a first transmitting module and a first receiving module. The second transceiver module further includes a second transmitting module and a second receiving module. One transceiver module can support a multi-link communication device operating on one link.

[0028] In a sixth aspect, a multi-link communication device is provided, comprising:

[0029] A first transceiver module obtains a first PPDU transmitted by a first multi-link device on a first link;

[0030] The second transceiver module is configured to send a third PPDU on a second link, where an end time of the third PPDU is no later than an end time of the second PPDU, and the second PPDU is sent on the first link in response to the first PPDU.

[0031] In one possible design, the first transceiver module further includes a first transmitting module and a first receiving module. The second transceiver module further includes a second transmitting module and a second receiving module. One transceiver module can support a multi-link communication device operating on one link.

[0032] In conjunction with the fifth or sixth aspect, in one possible implementation, the end time of the third PPDU is no later than the end time of the second PPDU, where "no later" includes earlier than or equal to the end time of the second PPDU. Optionally, the start time of the third PPDU is no earlier than the end time of the first PPDU, where "no earlier than" includes later than or equal to the end time of the first PPDU. Optionally, the first multi-link device and the third multi-link device belong to the same basic service set (BSS). The end time can also be referred to as the end moment, and the start time can also be referred to as the start moment.

[0033] In a seventh aspect, a multi-link communication device is provided, comprising: a processor and a memory; the memory is configured to store computer instructions, and when the processor executes the instructions, the communication device performs the method described in any of the above aspects. The communication device may be the multi-link device described in the first aspect or a chip therein, or the first multi-link device described in the second aspect or a chip therein; or the communication device may be the multi-link device described in the third aspect or a chip therein.

[0034] In an eighth aspect, a communication device is provided, comprising: a processor; the processor being coupled to a memory and configured to read instructions from the memory and then execute the method described in any of the above aspects according to the instructions. The communication device may be the multi-link device described in the first aspect or a chip therein, or the first multi-link device described in the second aspect or a chip therein; or the communication device may be the multi-link device described in the third aspect or a chip therein.

[0035] In a ninth aspect, a computer-readable storage medium is provided, wherein instructions are stored in the computer-readable storage medium. When the computer-readable storage medium is run on a computer, the computer can execute the method described in any one of the above aspects.

[0036] In a tenth aspect, a computer program product comprising instructions is provided, which, when executed on a computer, enables the computer to execute the method described in any one of the above aspects. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 is a schematic diagram of a multi-link communication scenario;

[0038] Figure 2 A timing diagram of multi-link communication for synchronous access to multiple links provided in an embodiment of the present application;

[0039] Figure 3 A timing diagram of a single-link communication accessed to a single link provided in an embodiment of the present application;

[0040] Figure 4 A timing diagram of a multi-link communication provided in an embodiment of the present application Figure 1 ;

[0041] Figure 5 Another timing diagram of multi-link communication provided in the embodiment of the present application Figure 2 ;

[0042] Figure 6 A timing diagram of another multi-link communication provided in an embodiment of the present application Figure 3 ;

[0043] Figure 7 A timing diagram of another multi-link communication provided in an embodiment of the present application Figure 4 ;

[0044] Figure 8 A timing diagram of another multi-link communication provided in an embodiment of the present application Figure 5 ;

[0045] Figure 9 A schematic diagram of the structure of a multi-link communication device provided in an embodiment of the present application Figure 1 ;

[0046] Figure 10 A schematic diagram of the structure of another multi-link communication device provided in an embodiment of the present application Figure 2 ;

[0047] Figure 11 A schematic diagram of the structure of another multi-link communication device provided in an embodiment of the present application Figure 3 . DETAILED DESCRIPTION

[0048] The embodiments of the present application are described below in conjunction with the accompanying drawings in the embodiments of the present application. The network architecture and business scenarios described in the embodiments of the present application are intended to more clearly illustrate the technical solutions of the embodiments of the present application and do not constitute a limitation on the technical solutions provided by the embodiments of the present application. It is known to those skilled in the art that with the evolution of network architecture and the emergence of new business scenarios, the technical solutions provided by the embodiments of the present application are also applicable to similar technical problems.

[0049] The solution of the embodiments of the present application is applicable to communication between at least two multi-link devices. A multi-link device is a device that can operate on multiple links. Multiple links are multiple links that differ in the frequency domain. The multiple links can be multiple different frequency bands, or they can be different channels within the same frequency band. Optionally, in a WLAN system, the frequency bands may include 2.4 GHz, 5 GHz, 6 GHz, etc. The bandwidth of a channel within a frequency band may be 20 MHz, 40 MHz, 80 MHz, 160 MHz, 320 MHz, etc., with a basic unit of 20 MHz. Subsequently, the channel bandwidth may be further expanded, and the basic unit may be 40 MHz or larger.

[0050] A multi-link device includes multiple stations (STAs). One station corresponds to one link and works on the corresponding link. A station can be a non-AP station or an AP station. Figure 1 An exemplary communication scenario of an embodiment of the present application is shown. Figure 1 As shown, the communication system includes a first link device and a second multi-link device. The multi-link device includes multiple stations (e.g., STA1, STA2, ... STAn), and the multiple STAs work on multiple links (e.g., link 1, link 2, ... link n), wherein one station works on one link, wherein the multiple stations may also belong to a multi-link entity, and the link entity shares a media access control MAC (media access control) service access point SAP (service access point). It can be understood that Figure 1 The number of multi-link devices, the number of sites in the multi-link devices, and the number of links included in the illustrated communication scenario are merely exemplary and do not constitute a limitation to the present application.

[0051] In one example, the multi-link device is a multi-link access point, including multiple access point (AP) sites, one of which corresponds to a link and operates on the corresponding link. In another example, the multi-link device is a multi-link site, including multiple non-access point sites, one of which corresponds to a link and operates on the corresponding link. In another example, the multi-link device may include both access point sites and non-access point sites. Therefore, the solution of the embodiment of the present application can be applied not only to communication between a multi-link access point and a multi-link site, but also to communication between at least two multi-link access points, and also to communication between at least two multi-link sites, and of course also to communication between multi-link devices including both access point sites and non-access point sites.

[0052] The access point (AP) included in a multi-link device can be a communication device with wireless communication capabilities, providing services to non-access point sites, enabling mobile users to access wired networks. It can be deployed in homes, buildings, and campuses, with a typical coverage radius of tens to hundreds of meters. Of course, it can also be deployed outdoors. The AP acts as a bridge between wired and wireless networks, connecting wireless sites and then connecting the wireless network to the Ethernet. The AP can support multiple communication protocols, such as cellular and WLAN. Optionally, the AP can be a device equipped with a wireless fidelity (WiFi) chip and support WLAN protocols. For example, the AP can support the next generation of 802.11ax. Optionally, a multi-link AP can also support 802.11ax, 802.11ac, 802.11n, 802.11g, 802.11b, and 802.11a.

[0053] The stations included in a multi-link device can be communication devices with wireless communication capabilities that can support multiple communication protocols, such as cellular communication protocols and WLAN communication protocols. Optionally, the STA can be a device with a wireless fidelity (WiFi) chip that can support WLAN communication protocols. For example, a multi-link STA can support the next generation of 802.11ax. Optionally, the STA can also support multiple WLAN standards such as 802.11ax, 802.11ac, 802.11n, 802.11g, 802.11b, and 802.11a. STAs can also be terminal devices, such as mobile phones supporting WiFi communication capabilities, tablets supporting WiFi communication capabilities, set-top boxes supporting WiFi communication capabilities, smart TVs supporting WiFi communication capabilities, smart wearable devices supporting WiFi communication capabilities, in-vehicle communication devices supporting WiFi communication capabilities, and computers supporting WiFi communication capabilities.

[0054] Multi-link devices operating on multiple links are often unable to support simultaneous transmission and reception on multiple links due to energy leakage between links and insufficient processing power. Even if a multi-link device allows simultaneous transmission and reception on multiple links, packets sent on one link may interfere with packets received on another link, resulting in poor communication quality. Therefore, various solutions have been proposed for situations where two or more links of a multi-link device cannot transmit and receive simultaneously.

[0055] One solution is the synchronous transmission method. The main principle is to access the channel simultaneously through multiple links competing for the channel independently. In addition, the data packets sent on the multiple links occupy the same length of time (if necessary, this can be achieved by filling in garbage information bits). An implementation method of accessing the channel at the same time includes: when a multi-link device competes for the channel on one link, such as using enhanced distributed channel access (EDCA), backs off to 0, and seizes the opportunity to send, the multi-link device looks back on the other links to see if the point coordination function interframe space (PIFS) time is idle. If it is idle, multiple links send at the same time. If it is busy, you can choose to send on a single link, or choose not to send. If Figure 2 As shown in the figure, the AP competes for the channel through EDCA on link 1, and the backoff count returns to 0. Then, it checks the PIFS time on link 2. If it is idle, it sends the physical layer protocol data unit (PPDU) on both links at the same time. The PPDUs sent on the two links have the same transmission duration. Then, after a fixed interval, such as the SIFS (Short Interframe Space) defined by 802.11, the multi-link device receives the confirmation frame of the station response on both links. Figure 2 The Block Acknowledgement (BA) frame is used as an example, but it could also be an Acknowledgement (Ack) frame. Using a synchronous transmission method can avoid the problem of simultaneous transmission and reception on multiple links. However, in this scheme, a multi-link device first competes for a channel on one link and then sends data packets on other links that are idle within the PIFS time. However, these other links do not perform regular listening and backoff, but instead check to see if they are busy within the PIFS time. As a result, stations on the multi-link device can preferentially access the channel on other links, which is unfair to other stations.

[0056] Another solution is to prohibit simultaneous transmission and reception. The stations in the multi-link device only send data packets on one of the links. In order to avoid simultaneous transmission and reception, the multi-link device needs to prohibit the receiving end of the data packet and other stations in the basic service set (BSS) on the other link from competing for the channel to send data, that is, stop its backoff. There are many scenarios for a multi-link device to send on one link, such as a multi-link device has data to send on only one of the links, or a multi-link device competes for the channel on one of the links first, but the other links are busy at this time. For example Figure 3As shown, the AP in a multi-link device competes for a channel on link 1 and sends a physical protocol data unit (PPDU) to site A. If site A is a multi-link site, upon receiving a data packet from the AP, site A must stop backing off on other links until the data unit ends or the data unit transmission time plus the SIFS and the maximum transmission time of the confirmation message frame have passed. Similarly, if a multi-link device in this BSS hears the AP sending a data packet on link 1, it must also stop backing off on other links. By prohibiting simultaneous transmission and reception, multi-link sites in this BSS must stop backing off on links other than those on which they received data packets. While this prevents sites from transmitting and receiving simultaneously, it wastes idle link spectrum resources.

[0057] Therefore, the embodiment of the present application provides a multi-link communication method, which can not only ensure the fairness of multi-link access, but also reduce the idle rate of multi-links and improve frequency efficiency in a scenario where simultaneous multi-link transmission and reception is not supported.

[0058] Example 1

[0059] In scenarios where simultaneous multi-link transmission and reception is not supported, it is proposed that multiple links of a multi-link station independently compete for channels. The first link to seize the channel sends the PPDU first, and the second link to seize the channel sends the PPDU later. However, the end time of the later PPDU must be no later than the end time of the earlier PPDU. For example, the end time of the later PPDU is the same as the end time of the earlier PPDU. In other words, the start time does not need to be the same, but the end time is the same. In this application, the end time can also be referred to as the end moment or end time point, and the start time can also be referred to as the start moment or start time point.

[0060] An embodiment of the present application provides a multi-link communication method, which can be applied to a multi-link device. The method includes:

[0061] S101, a multi-link device sends a first physical layer protocol data unit PPDU on a first link;

[0062] The multi-link device can operate on at least two links, including a first link and a second link, wherein the multi-link device does not support simultaneous transmission and reception of PPDUs on the first link and the second link. The first PPDU can be sent by a station in the multi-link device operating on the first link. In one example, the multi-link device does not support simultaneous transmission and reception of PPDUs on the first link and the second link, including: the multi-link device does not support simultaneous transmission of physical layer protocol data units of a first bandwidth on the first link and reception of physical layer protocol data units of a second bandwidth on the second link, and / or the multi-link device does not support simultaneous reception of physical layer protocol data units of a first bandwidth on the first link and transmission of physical layer protocol data units of a second bandwidth on the second link. The "simultaneous" refers to a non-empty temporal intersection of the PPDUs of the first bandwidth and the PPDUs of the second bandwidth. Optionally, the first bandwidth and the second bandwidth include, but are not limited to, one of 20 MHz, 40 MHz, 80 MHz, 160 MHz, and 320 MHz.

[0063] In addition, "simultaneous transmission and reception" in this application does not mean that there is no difference in time. "Simultaneous transmission and reception" can mean that the transmission time of the PPDU of the first bandwidth sent on the first link and the transmission time of the PPDU of the second bandwidth sent on the second link have a non-empty intersection in time. For example, the duration of the PPDU of the first bandwidth is T1 = E1-S1, and the start and end times are [S1, E1], and the duration of the PPDU of the second bandwidth is T2 = E2-S2, and the start and end times are [S2, E2]. Then, [S1, E1] and [S2, E2] have a non-empty intersection.

[0064] Optionally, the multi-link device may send a first PPDU on the first link via a contention channel. The contention channel method may be EDCA or multi-user EDCA (MU EDCA) specified in the 802.11 protocol, or a traditional contention channel method. In one example, the EDCA contention method includes: the multi-link device first senses for an AIFS period, then begins a backoff, and only begins transmitting data after the backoff reaches 0. If the channel is busy during the backoff process, the backoff is suspended or stopped. The device waits until the next channel is idle and then re-contentions for the channel based on the last suspended backoff value, including the AIFS sensing and backoff process. Optionally, the multi-link device may have already seized a channel on the first link and, within the seized transmission opportunity (TXOP), send the first PPDU on the first link, where the first PPDU is a data packet within the TXOP. Optionally, the first PPDU may include a data frame, a management frame, a control frame, or an aggregated packet of multiple frames.

[0065] S102: The multi-link device sends a second PPDU on a second link through a contention channel, wherein an end time of the second PPDU is no later than an end time of the first PPDU.

[0066] The multi-link device competes for a channel on the second link and, after winning the channel, sends a second PPDU on the second link. The second PPDU is sent no earlier than (equal to or later than) the first PPDU. The second PPDU may be sent by a station in the multi-link device operating on the second link. The multi-link device may also compete for a channel on the second link using EDCA or multi-user EDCA (MU EDCA) as specified in the 802.11 protocol, or using a traditional channel contention method. Optionally, the second PPDU may include a data frame, a management frame, a control frame, or an aggregated packet of multiple frames. Optionally, the multi-link device may not compete for a channel and instead send the second PPDU within a single TXOP.

[0067] In one implementation, the end time of the second PPDU is no later than the end time of the first PPDU, including: the end time of the second PPDU is the same as the end time of the first PPDU. Since the first PPDU is aligned with the second PPDU, the situation where the multi-link device may transmit and receive at the same time is avoided. It should be noted that, since the multi-link device knows the duration of the first PPDU, when sending the second PPDU, the duration of the second PPDU can be accurately determined based on the duration of the first PPDU, so that the end time of the second PPDU is no later than the end time of the first PPDU. In another way, the multi-link device can also know the transmission duration of the first PPDU by listening to the length field in the L-SIG field of the traditional preamble code of the first PPDU sent first.

[0068] Optionally, the length of the TXOP indicated by the second PPDU may be set to be the same as the TXOP duration indicated by the first PPDU, wherein the information indicating the TXOP duration may be located in the physical layer preamble of the PPDU or in the duration field of the MAC header of the PPDU. Therefore, in one implementation, the first PPDU includes first TXOP duration information, the first TXOP duration information indicating the duration of the first TXOP, and the second PPDU includes second TXOP duration information, the second TXOP duration information indicating the duration of the second TXOP, and the duration of the first TXOP is the same as the duration of the second TXOP. The first TXOP duration information is carried in the physical layer preamble of the first PPDU or the duration field of the MAC header of the first PPDU; the second TXOP duration information is carried in the physical layer preamble of the second PPDU or the duration field of the MAC header of the second PPDU.

[0069] Before executing steps S101 and S102, the station can obtain the capability information of the multi-link AP when associating with the AP or listening to beacon frames sent by the AP to determine which links the multi-link AP cannot support simultaneous transmission and reception, and which links it can support simultaneous transmission and reception. Specifically, the station can determine which links the multi-link AP cannot support simultaneous transmission and reception of PPDUs with a first bandwidth and PPDUs with a second bandwidth, where the PPDU bandwidth is a factor that determines multi-link self-interference. This capability information can be implicit or explicit. The specific indication method is not specifically limited in the embodiments of this application.

[0070] Optionally, the method further includes:

[0071] S103, the multi-link device receives first confirmation information in response to the first PPDU on the first link;

[0072] S104: The multi-link device receives second confirmation information in response to the second PPDU on the second link.

[0073] The first acknowledgment message is sent by the destination receiver of the first PPDU, and the second acknowledgment message is sent by the destination receiver of the second PPDU. The destination receivers of the first PPDU and the second PPDU may be multi-link devices, or may not be multi-link devices, but may be devices operating on the link, such as an AP or a non-AP STA. The destination receiver of the first PPDU may be located in the same basic service set (BSS) as the first multi-link device, and the destination receiver of the second PPDU may be located in the same BSS as the first multi-link device. Optionally, the destination receiver of the first PPDU and the destination receiver of the second PPDU may be the same destination receiver or different destination receivers. If the destination receivers of the first PPDU and the second PPDU are the same destination receiver, the receiver is a multi-link device, which is not limited in this application. Optionally, the acknowledgment message is sent after a preset time interval of the PPDU, which may be a SIFS. Optionally, the first acknowledgment message and the second block acknowledgment message may be a block acknowledgment (BA) or ACK. Optionally, the first acknowledgment message and the second acknowledgment message have the same duration.

[0074] In one embodiment, the multi-link device sending the first PPDU may be a multi-link station, and the destination receiving end of the first PPDU may be an access point. In another embodiment, the multi-link device sending the first PPDU may be a multi-link access point, and the destination receiving end of the first PPDU may be a station. To let the destination receiving end know which device is sending the first PPDU, the physical layer preamble of the first PPDU optionally includes an uplink / downlink indicator (also referred to as an uplink / downlink indicator). The uplink / downlink indicator is used to indicate the transmission direction of the first PPDU, which can be uplink or downlink. A PPDU sent by an AP in a multi-link device to a station is downlink, and a PPDU sent by a station in a multi-link device to an AP is uplink. It is worth noting that if the sender of the first PPDU is a multi-link AP, when the multi-link AP first sends the first PPDU on the first link, other multi-link stations in the BSS cannot compete for channels on other links (e.g., the second link) and cannot send PPDUs to the multi-link AP on the second link, thereby avoiding simultaneous transmission and reception at the multi-link AP. If the transmitting end is a multi-link station, when the multi-link station first sends the first PPDU on the first link, other multi-link stations in the BSS can compete for channels on other links (e.g., the second link) and then send a second PPDU to the access point in the BSS. The second PPDU is sent at a time equal to or later than the first PPDU, but the end time of the second PPDU is no later than the end time of the first PPDU. In one embodiment, the end time of the second PPDU is the same as the end time of the first PPDU. It is understood that, for downlink transmission, the first PPDU can also be sent by an access point in a multi-link device, with the destination receiving end being a station; for uplink transmission, the first PPDU can also be sent by a station in a multi-link device, with the destination receiving end being an access point.

[0075] For example, Figure 4 The figure shows a downlink transmission scenario in which a multi-link AP sends PPDU1 to site A on link 1 by competing for a channel, then competes for a channel on link 2 and sends PPDU2 to site B. The start time of PPDU2 is no earlier than (equal to or later than) the start time of PPDU1. Figure 4 The figure shows the case where the end time of PPDU2 is aligned with the end time of PPDU1. Station A and Station B reply with acknowledgments, such as BAs, on channels on Link 1 and Link 2, respectively. This embodiment can also be extended to allow the AP to send multi-user data packets to multiple stations on Link 1 and Link 2, such as via 802.11ax HE MU PPDUs, using OFDMA, MU-MIMO, or a combination thereof.

[0076] For example, Figure 5 The figure shows an uplink transmission scenario where a multi-link STA sends PPDU1 to access point AP1 on link 1, then competes for a channel on link 2 and sends PPDU2 to access point AP2. The start time of PPDU2 is no earlier than the start time of PPDU1, including being equal to or later than the start time of PPDU1. Figure 5 The case of equal is shown in FIG. The end time of PPDU2 is aligned with the end time of PPDU1. AP1 and AP2 reply the confirmation information on the channel on link 1 and link 2 respectively. Figure 5 In the scenario shown, AP1 and AP2 may also be access points operating on different links in the same multi-link access point, or may be access points in different multi-link devices, and so on.

[0077] For ease of description, the multi-link device in steps S101 and S102 is referred to as the first multi-link device. Other multi-link stations (non-AP STAs) within the same BSS as the first multi-link device can perform Tunneled Direct Link Setup (TDLS) transmission. For example, a station (non-AP STA) in the other multi-link stations can send other message packets to another station (non-AP STA) within the transmission time of the first multi-link device sending the first PPDU. The specific implementation method is as follows:

[0078] The first implementation method: If the first multi-link device is a multi-link AP, that is, the first PPDU is a downlink transmission, when the multi-link AP first sends the first PPDU on the first link, then other multi-link stations in the BSS can transmit TDLS message packets on other links (second links) through channel competition, wherein the sending time of the TDLS message packet is equal to or later than the sending time of the first PPDU. When the receiving object of the TDLS message packet is the receiving object of the first PPDU, it is necessary to adopt the end time of the TDLS message packet mentioned in this embodiment not later than the end time of the first PPDU sent by the AP, including the end time of the TDLS message packet being earlier than the end time of the first PPDU, or the end time of the TDLS message packet being the same as the end time of the first PPDU. In other cases, there may be no restrictions.

[0079] Second implementation method: If the first multi-link device is a multi-link station, that is, the first PPDU is an uplink transmission, when the multi-link station first sends the first PPDU on the first link, other multi-link stations in the BSS can transmit TDLS message packets on other links (second links) through channel competition. However, the recipient of the TDLS message packet cannot be the first multi-link device (i.e., the multi-link station) that sent the first PPDU. There are no other restrictions.

[0080] By adopting the solution of the embodiment of the present application, the multi-link device independently competes for channels on multiple links. The link that competes for the channel first sends the PPDU first, and the link that competes for the channel later sends the PPDU later. This can not only ensure the fairness of multi-link access, but also reduce the idle rate of multiple links and improve frequency efficiency.

[0081] Embodiment 2 provides another multi-link communication method, which can be applied to a multi-link device. The method includes:

[0082] S201, a first multi-link device sends a first physical layer protocol data unit PPDU on a first link;

[0083] Refer to the description of the aforementioned step S101, which will not be repeated here. Optionally, the first multi-link device does not support simultaneous transmission and reception on the first link and the second link.

[0084] S202, the second device sends a second PPDU in response to the first PPDU after a preset time interval of receiving the first PPDU on the first link;

[0085] Optionally, the preset time interval may be SIFS.

[0086] S203: After a preset time interval, the first multi-link device receives a second PPDU in response to the first PPDU on the first link;

[0087] Correspondingly, the intended recipient of the first PPDU is a second device. After receiving the first PPDU, the second device sends a second PPDU in response to the first PPDU on the first link after a preset time interval. The second device can only operate on a single link (i.e., the first link) or support multi-link communication and belong to the same BSS as the first multi-link device. The preset time interval is determined by the protocol and can be SIFS. The first PPDU can include data frames, management frames, or control frames, or it can include an aggregation of multiple frames.

[0088] The first multi-link device can be a multi-link AP or a multi-link STA. In one implementation, the first PPDU includes data information, and the second PPDU includes confirmation information in response to the data information. If the first PPDU is downlink, the first multi-link device is a multi-link AP; if the first PPDU is uplink, the first multi-link device is a multi-link STA. In another implementation, the first PPDU includes trigger information for triggering the second device to send data information, and the second PPDU includes data information scheduled by the trigger information, and the first multi-link device is a multi-link AP. The physical layer preamble of the PPDU here includes an uplink / downlink indication. The explanation of the uplink / downlink indication is described in the aforementioned embodiment 1 and is not repeated here.

[0089] Optionally, in S204, the third multi-link device obtains the first PPDU sent by the first multi-link device on the first link. The order of S203 and S204 is not limited. "Acquisition" can be reception or identification. Optionally, the third multi-link device can also obtain a second PPDU sent by the second device on the first link in response to the first PPDU. After obtaining the first PPDU or the second PPDU, the third multi-link device can determine the end time or transmission duration of the second PPDU based on the information carried in the first PPDU and / or the second PPDU, and thereby determine the transmission duration or end time of the third PPDU to be sent based on the end time or transmission duration of the second PPDU. For details on how to obtain, please refer to the description below.

[0090] S205: The third multi-link device sends a third PPDU on the second link, where the end time of the third PPDU is no later than the end time of the second PPDU.

[0091] Optionally, the third multi-link device may also send a third PPDU via a contention channel. Specifically, the third multi-link device, which belongs to the same basic service set as the first multi-link device, may send a third PPDU via a contention channel on the second link after identifying or receiving the first PPDU and at or after the end time of the first PPDU. The sending time of the third PPDU is later than or equal to the end time of the first PPDU, and the end time of the third PPDU is earlier than or equal to the end time of the second PPDU. In one possible implementation, the end time of the third PPDU is the same as the end time of the second PPDU. However, the sending time of the third PPDU must not be earlier than the end time of the first PPDU sent by the first multi-link device. That is, the second device sends the third PPDU via a contention channel on the second link at or after the end time of the first PPDU, thereby preventing the first multi-link device from sending and receiving on the first and second links at the same time. Furthermore, only when the third bandwidth of the third PPDU and the first bandwidth of the first PPDU meet a certain relationship can it be necessary to avoid overlapping time (simultaneous transmission and reception) between the first link device transmitting the first PPDU on the first link and the second link receiving the third PPDU; otherwise, the solution of the embodiments of the present application is not required. The above relationship can be that the first bandwidth and the third bandwidth are greater than a certain bandwidth threshold, and the principle is that the frequency interval between the first PPDU of the first bandwidth and the third PPDU of the third bandwidth is less than a certain threshold.

[0092] Optionally, the third multi-link device may include a third-party multi-link site that is not the destination receiving end of the first PPDU and the destination receiving end of the first PPDU, i.e., the second device. After identifying or receiving the first PPDU, the third multi-link device will independently compete for channels on other links (second links), and send the third PPDU after competing for the channel. In one embodiment, the third-party multi-link device in this BSS starts to compete for the channel at or after the end time of the first PPDU, and starts to send the third PPDU after obtaining the channel sending right. In one example, the method for identifying or receiving the first PPDU includes identifying indication information of the preamble code of the first PPDU, including but not limited to downlink / uplink indication information, indication information of the MAC header in the first PPDU, such as the MAC address of the transmitter, etc.

[0093] The PPDU sent by the multi-link device in this embodiment may be a single-user message packet sent to a single site, or a multi-user message packet (including OFDMA or MU-MIMO, or a mixture thereof) sent to multiple sites.

[0094] S206: Correspondingly, the first multi-link device receives, on the second link, a third PPDU sent by the third multi-link device on the second link, where the end time of the third PPDU is no later than the end time of the second PPDU. In one embodiment, the end time of the third PPDU is equal to the end time of the second PPDU.

[0095] Since the end time of the third PPDU sent by the third multi-link device is not later than the end time of the second PPDU, the third multi-link device needs to obtain the end time or transmission duration of the second PPDU. The third multi-link device may determine the end time of the third PPDU in the following manner:

[0096] In a first implementation mode, a first PPDU sent by a first multi-link device carries a length or time indication (or transmission duration information) for indicating the transmission duration of a second PPDU. A third multi-link device can determine the transmission duration of the second PPDU based on the transmission duration information in the first PPDU, thereby determining the transmission duration and / or end time of the third PPDU based on the transmission duration of the second PPDU.

[0097] In a second embodiment, a physical layer preamble of a second PPDU sent by the second device includes the transmission duration information, where the transmission duration information is used to indicate the transmission duration of the second PPDU. For example, the transmission duration information is the length field in the L-SIG field of a conventional preamble. The third multi-link device can determine the transmission duration of the second PPDU based on the transmission duration information included in the physical layer preamble of the second PPDU, thereby determining the transmission duration and / or end time of the third PPDU based on the transmission duration of the second PPDU.

[0098] Optionally, the transmission duration information carried in the first PPDU sent by the first multi-link device may also be used to indicate that the second PPDU starts to be sent at a fixed interval, such as SIFS time, after the end of the first PPDU.

[0099] It should be noted that if the third multi-link device is the intended recipient of the first PPDU, that is, the second device, then the second device itself knows the duration of the second PPDU being sent. Therefore, the first and second embodiments described above may not be used to determine the transmission duration and / or end time of the third PPDU. In this case, the second device is a multi-link device. If the third multi-link device is a multi-link device other than the first and second devices, the first and second embodiments described above may be used to determine the transmission duration and / or end time of the third PPDU. In this case, the second device may also be a device operating only on a single link (i.e., the first link) or may support multi-link.

[0100] For example, when the first PPDU sent by the first multi-link device includes a data frame or a management frame, the second PPDU responded by the second device includes acknowledgment information. Because the transmission time of the acknowledgment information is shorter, the transmission duration obtained by other multi-link devices in the BSS on other links through the above-described method is also shorter. Other multi-link devices include devices other than the first multi-link device in the BSS, such as a third multi-link device. To inform other multi-link stations in the BSS of the transmission time of the acknowledgment information, the message packet sent by the multi-link AP may carry the transmission time information of the acknowledgment information in the MAC header. In one example, this transmission time information may be a length field, measured in bytes, similar in function to the length field in the L-SIG of a traditional preamble. For example, other multi-link stations may determine the transmission time of the third PPDU based on the length: transmission time = length field / 6 Mbps. Optionally, the length field may be carried in the length subfield of the triggered response schedule (TRS) field in 802.11ax. Other subfields in the TRS field may be set to special or reserved values. Of course, due to the limited transmission time for the acknowledgment information, the transmission opportunity available to other devices is shorter, and the protocol may prohibit or allow transmission within this transmission time. Furthermore, the second PPDU responded by the second device may include not only the acknowledgment information but also other frames, and similarly requires the first PPDU to carry transmission duration information, for example, length indication information in the MAC header to indicate the transmission duration of the second PPDU.

[0101] For another example, when the first PPDU sent by a multi-link AP includes a trigger frame carrying trigger information, it may also include other aggregated frames. The trigger frame is used to schedule multiple users for uplink OFDMA transmission, MU-MIMO transmission, or mixed OFDMA and MU-MIMO transmission. In this case, the second PPDU that the multiple stations respond to based on the trigger frame includes uplink data, such as a data frame. In this case, the multi-link stations within the BSS obtain longer transmission opportunities on other links through the above-mentioned method. In another example, the trigger information included in the first PPDU may not be carried in a separate trigger frame. The trigger information may also be carried in the MAC header of the MAC frame in the first PPDU, such as the trigger information carried in the TRS field of a PPDU that complies with the 802.11ax standard. Furthermore, the trigger frame sent by the multi-link AP includes a length indicator for indicating the transmission time of the second PPDU. The length indicator can be expressed in time units or in bytes. When expressed in bytes, when the receiver uses the length indicator to calculate the transmission time of the second PPDU, it calculates the length by dividing the number of bytes carried in the length field by 6 Mbps, rather than by the actual rate of the second PPDU.

[0102] In addition, the third TXOP duration of the third PPDU sent by the third multi-link device in the BSS may be set according to the first TXOP duration of the first PPDU or the transmission duration of the second PPDU.

[0103] Optionally, the duration of the third TXOP of the third PPDU may be set to the minimum value or the earliest end value of the following two.

[0104] 1. The first TXOP duration of the first PPDU;

[0105] 2. The transmission duration of the second PPDU indicated by the length field of the first PPDU, or the transmission duration of the second PPDU indicated by the length field of the first PPDU plus SIFS and the transmission duration of the response and confirmation information of the second PPDU.

[0106] Therefore, in one example, the third PPDU includes third TXOP duration information indicating a third TXOP duration. The third TXOP duration does not exceed: the minimum or earliest end value of the first TXOP duration and the second TXOP duration indicated by the first TXOP duration information in the first PPDU; wherein the second TXOP duration is the transmission duration of the second PPDU, or the transmission duration of the second PPDU + SIFS + the transmission duration of the acknowledgment information in response to the second PPDU. Optionally, the first TXOP duration information is carried in the duration field of the physical layer preamble of the first PPDU or the MAC header of the first PPDU, and the third TXOP duration information is carried in the duration field of the physical layer preamble of the third PPDU or the MAC header of the third PPDU. The earliest end value refers to the earliest end time among the various durations. The third TXOP duration does not exceed the earliest end value, which means that the end time value of the third TXOP duration does not exceed the earliest end value. The third TXOP duration does not exceed the minimum value, which means that the third TXOP duration does not exceed the minimum duration.

[0107] The following briefly introduces the solutions of the embodiments of the present application using several examples.

[0108] For example, Figure 6 As shown in the figure, after successfully competing for the channel of link 1, the multi-link AP sends PPDU1 containing a trigger frame, scheduling stations A1, A2, and A3 to send an uplink multi-user data packet (PPDU2). The length field in the trigger frame indicates the transmission duration of the uplink multi-user data packet (PPDU2). After receiving PPDU1 sent by multi-link AP1 on link 1, the third-party multi-link station STAB in this BSS starts competing for the channel of link 2 at the end of PPDU1, and then sends PPDU3. Figure 6 Two possible times for STAB to send PPDU3 on link 2 are listed, which may be earlier or later than the start time of scheduling stations A1, A2 and A3 to send uplink multi-user data packets (PPDU2). Of course, it can also be equal to ( Figure 6 (Not shown). Of course, whether PPDU3 starts before, after, or equal to the start time of stations A1, A2, and A3 transmitting the uplink multi-user data packet (PPDU2) depends on when STAB seizes the channel on Link 2. Furthermore, the end time of STAB transmitting PPDU3 on Link 2 coincides with the end time of the scheduled transmission of the uplink multi-user data packet by stations A1, A2, and A3. Stations A1, A2, and A3 may not be multi-link stations, while station B is a multi-link station. Of course, if stations A1, A2, and A3 are also multi-link stations, they can also compete for the channel on Link 2 and transmit PPDU3.

[0109] For example, Figure 7As shown in the figure, after successfully competing for the channel of link 1, the multi-link AP sends PPDU1 containing downlink data. The receivers of the downlink data are stations A1, A2, and A3. Stations A1, A2, and A3 send PPDU2 containing confirmation information after the SIFS time. After receiving PPDU1 sent by multi-link AP1 on link 1, the third-party multi-link station STAB in this BSS starts to compete for the channel of link 2 at the end of PPDU1, and then sends PPDU3. Among them, stations A1, A2, and A3 do not need to be multi-link stations, and station B is a multi-link station. Of course, if stations A1, A2, and A3 are also multi-link stations, they can also compete for the channel on link 2 and send PPDU3.

[0110] For example, Figure 8 As shown, after successfully competing for a channel on Link 1, a multi-link STA transmits PPDU1 containing uplink data, with the AP as the recipient. After a SIFS period, the AP transmits PPDU2 containing acknowledgment information. PPDU2 may also include other frames. Simultaneously, when STA A's PPDU1 ends, the AP begins competing for a channel on Link 2. After securing a channel, it transmits PPDU3 on Link 2 to Station A or another station. The end time of PPDU3 is consistent with the method described above and will not be further described.

[0111] In the scenario of the second embodiment, other multi-link stations (except the first multi-link device and the second device) belonging to the same BSS as the first multi-link device can perform Tunneled Direct Link Setup (TDLS) transmission. For example, a station in the other multi-link stations (a non-AP STA) can send other message packets to another station (non-AP STA) through channel competition on the second link within the transmission time of the second device sending the second PPDU. The specific implementation method is as follows:

[0112] First implementation method: If the first multi-link device is a multi-link AP and the second device is a multi-link station, when the multi-link AP first sends the first PPDU on the first link (that is, the first PPDU is a downlink transmission), other multi-link stations in the BSS can transmit TDLS message packets on other links (second links) after the end time of the first PPDU through the contention channel. However, the recipient of the TDLS message packets cannot be the receiver of the first PPDU, that is, the second device. There are no other restrictions.

[0113] Second implementation method: If the first multi-link device is a multi-link station, when the multi-link station first sends the first PPDU on the first link, other multi-link stations in the BSS can transmit TDLS message packets on other links (second links) through the contention channel. When the TDLS message packet is received by the first multi-link station, the end time of the TDLS message packet mentioned in this embodiment needs to be earlier than or equal to the end time of the second PPDU sent by the second device, including earlier than or equal to. There are no restrictions in other cases.

[0114] By adopting the solution of the embodiments of the present application, in a scenario where simultaneous multi-link transmission and reception is not supported, when a PPDU sent by a first multi-link device on a first link is received, the multi-link device can start to seize the channel (including actions such as listening and backing off) on another link when the PPDU ends, thereby sending the PPDU. This can not only ensure the fairness of multi-link access, but also reduce the idle rate of multi-links and improve frequency efficiency.

[0115] It should be noted that the solutions of Embodiment 1 and Embodiment 2 of the present application can be used not only in scenarios where the multi-link device does not support simultaneous transmission and reception on the first link and the second link, but also in scenarios where the multi-link device supports simultaneous transmission and reception on the first link and the second link.

[0116] Example 3

[0117] For multi-links that do not support simultaneous transmission and reception, the multi-link device first sends a message packet on one link. Since the energy of the message packet will leak to other links, even when the channels on other links are idle, the clear channel assessment (CCA) detection result is busy. The embodiment of the present application proposes that the multi-link device can test the power leakage of different power data packets to other links in advance under the condition that multiple links are idle through calibration, for example, the self-interference detected when the leakage is XdB. Therefore, for multi-links that do not support simultaneous transmission and reception, the multi-link device first sends a message packet on one link, and performs CCA on other links to detect whether the channel on this link is idle or busy. The detection threshold of the CCA detection on the other links needs to be backed off by (XC)dB, where C is a fixed safety value specified by the protocol and can be 0 or other values. This detection threshold backoff method can be applied to energy detection and signal detection. For example, when using signal detection, the usual main 20M signal detection threshold is -82dBm. That is, if the energy detected by CCA is greater than or equal to -82dBm, it means the channel is busy, otherwise it means the channel is idle. In a multi-link station scenario where one link sends a data packet, the detection threshold for CCA detection on the other links can be (-82 + X1 + -C1) dBm. C1 is an estimated safety value, which can be set by the protocol and can be 0 or other values. X1 is the leaked self-interference. When the power detected by CCA is greater than or equal to (-82 + X1 + -C1) dBm, the channel is considered busy; otherwise, the channel is considered idle. For example, when using energy detection, the energy detection threshold for the main 20 MHz channel is typically -62 dBm, (-62 + X2 - C2). C2 is an estimated safety value, which can be set by the protocol and can be 0 or other values. X2 is the leaked self-interference. When the power detected by CCA is greater than or equal to (-62 + X1 + -C1) dBm, the channel is considered busy; otherwise, the channel is considered idle. Optionally, X1 and X2 may be the same or different, and C1 and C2 may be the same or different.

[0118] The detection method of the embodiment of the present application can improve the accuracy of CCA detection, thereby enabling multi-link devices to more accurately determine the idle and busy status of the channel. It should be noted that the method for setting the detection threshold proposed in Example 3 is not limited to being applicable to the solutions of any of the above embodiments, but can also be applied to other scenarios of multi-link communication.

[0119] The above describes in detail the method of the embodiment of the present application, and the following provides an apparatus of the embodiment of the present application.

[0120] See Figure 9 , Figure 9It is a structural diagram of a multi-link communication device provided in an embodiment of the present application. The multi-link communication device can be used to implement any method and function related to the multi-link communication device in any of the aforementioned embodiments. The multi-link communication device 900 may include a transceiver module 902, and the transceiver module 902 includes: a first transceiver module 902a and a second transceiver module 902b. Optionally, the multi-link communication device includes a processing module 901. In one possible design, a transceiver module may correspond to a site in the multi-link device and may include a baseband circuit and a radio frequency circuit. In another possible design, a transceiver module may include a radio frequency circuit, and multiple radio frequency circuits are coupled to a baseband circuit. Therefore, the baseband circuit may be included in the processing module. It should be noted that the number of modules in the communication device 900 is only exemplary.

[0121] In one possible design, the multi-link communication device 900 can implement any of the methods and functions of the multi-link device in the first embodiment described above. For example, the processing module 901 is configured to generate a first PPDU and a second PPDU. Optionally, the processing module may also include a first processing module and a second processing module, with the first processing module configured to generate the first PPDU and the second processing module configured to generate the second PPDU. The first transceiver module 902a is configured to send the first PPDU on the first link, for example, for implementing step S101, and the second transceiver module 902b is configured to send the second PPDU on the second link via a contention channel, wherein the end time of the second PPDU is no later than the end time of the first PPDU, for example, for implementing step S102. Optionally, the first transceiver module 902a is further configured to receive first confirmation information on the first link, and the second transceiver module 902b is further configured to receive second confirmation information on the second link.

[0122] In another possible design, the multi-link communication apparatus 900 may implement any of the methods and functions of the first multi-link device in the second embodiment. For example, the processing module 901 is configured to generate a first PPDU; the first transceiver module 902a is configured to transmit the first PPDU on a first link, for example, for implementing step S201; the first transceiver module 902a is further configured to receive a second PPDU on the first link in response to the first PPDU, for example, for implementing step S203; and the second transceiver module 902b is configured to receive a third PPDU on a second link sent by a third multi-link device on the second link, where the end time of the third PPDU is no later than the end time of the second PPDU, for example, for implementing step S206.

[0123] In another possible design, the multi-link communication apparatus 900 may implement any of the methods and functions of the third multi-link device in the second embodiment. For example, the processing module 901 may be configured to generate a third PPDU; the first transceiver module 902a may be configured to obtain or receive the first PPDU on the first link, for example, to implement step S204; and the second transceiver module 902b may be configured to send the third PPDU on the second link, where the end time of the third PPDU is no later than the end time of the second PPDU, for example, to implement step S205.

[0124] In another possible design, the multi-link communication device can implement the CCA detection in the above-mentioned embodiment 3. For example, the transceiver module is used to perform CCA detection; the processing module is used to determine the idle or busy state of the channel based on the detection result of the transceiver module. The processing module is used to determine that the channel on the second link is busy when the power detected by the transceiver module on the channel on the second link is greater than or equal to (-82+X1+-C1)dBm; the processing module is used to determine that the channel on the second link is idle when the power detected by the transceiver module on the channel on the second link is less than (-82+X1+-C1)dBm.

[0125] See also Figure 10 , Figure 10 1 is a schematic diagram of the structure of a multi-link communication device provided in an embodiment of the present application. The multi-link communication device can be used to implement any of the methods and functions related to the multi-link communication device in any of the aforementioned embodiments. The multi-link communication device may include a processor 1001, a bus 1002, a radio frequency circuit 1004a, and a radio frequency circuit 1004b. Optionally, the multi-link communication device also includes a memory 1003. In one possible design, a station in the multi-link device includes a separate radio frequency circuit and baseband circuit, which can independently implement the transceiver functions on the link in which it is operating. In another possible design, a station in the multi-link device includes a common baseband circuit portion and an independent radio frequency circuit portion. The data transmitted by the station on the link in which it is operating can be generated by the common baseband circuit. In this case, the baseband circuit can be included in the processor 1001. The processor 1001 is used to execute instructions to control and manage the multi-link communication device, and also includes signaling or data processing. The bus 1002 is used to couple and connect the various components so that they can complete the exchange of data or information. The memory 1003 may include computer programs or instructions, and the processor 1001 may execute the instructions to implement the functions of the above method embodiments.

[0126] In one possible design, the multi-link communication device can implement any of the methods and functions of the multi-link device in the first embodiment above. For example, the processor 1001 is configured to generate a first PPDU and a second PPDU. Optionally, the processor can also be a baseband circuit configured to generate the first PPDU and the second PPDU. The radio frequency circuit 1004a is configured to send the first PPDU on the first link, for example, for implementing step S101, and the radio frequency circuit 1004b is configured to send the second PPDU on the second link via a contention channel, wherein the end time of the second PPDU is no later than the end time of the first PPDU, for example, for implementing step S102. Optionally, the radio frequency circuit 1004a is further configured to receive first confirmation information on the first link, and the radio frequency circuit 1004b is further configured to receive second confirmation information on the second link.

[0127] In another possible design, the multi-link communication apparatus may implement any of the methods and functions of the first multi-link device in the second embodiment. For example, the processor 1001 is configured to generate a first PPDU; the RF circuit 1004a is configured to send the first PPDU on a first link, for example, to implement step S201; the RF circuit 1004a is further configured to receive a second PPDU on the first link in response to the first PPDU, for example, to implement step S203; and the RF circuit 1004b is configured to receive a third PPDU on a second link sent by a third multi-link device on the second link, where the end time of the third PPDU is no later than the end time of the second PPDU, for example, to implement step S206.

[0128] In another possible design, the multi-link communication apparatus may implement any of the methods and functions of the third multi-link device in the second embodiment. For example, the processor 1001 may be configured to generate a third PPDU; the RF circuit 1004a may be configured to obtain or receive the first PPDU on the first link, for example, to implement step S204; and the RF circuit 1004b may be configured to transmit the third PPDU on the second link, where the end time of the third PPDU is no later than the end time of the second PPDU, for example, to implement step S205. Optionally, the processor 1001 may also be configured to obtain the transmission duration of the second PPDU based on the transmission duration information carried in the first PPDU and / or the second PPDU, thereby determining the transmission duration or end time of the third PPDU.

[0129] In another possible design, the multi-link communication device can implement the CCA detection in the above-mentioned embodiment 3. For example, the radio frequency circuit is used to perform CCA detection; the processor 1001 is used to determine the idle or busy state of the channel according to the detection result of the radio frequency circuit. The processor 1001 is used to determine that the channel on the second link is busy when the power detected by the radio frequency circuit 1004b on the channel on the second link is greater than or equal to (-82+X1+-C1)dBm; the processor 1001 is used to determine that the channel on the second link is idle when the power detected by the radio frequency circuit 1004b on the channel on the second link is less than (-82+X1+-C1)dBm.

[0130] See also Figure 11 , Figure 11 This is a schematic diagram of the structure of a multi-link communication device provided in an embodiment of the present application. The multi-link communication device can be used to implement any method and function related to the multi-link communication device in any of the aforementioned embodiments. The multi-link communication device 1100 can be a chip system for supporting a multi-link device to implement the functions involved in any of the aforementioned embodiments. The chip system may include a processor and optionally a memory for storing programs or instructions.

[0131] In one possible design, the processor is configured to execute a program or instruction to enable the multi-link communication device to implement any of the methods and functions in Example 1. In another possible design, the processor is configured to execute a program or instruction to enable the multi-link communication device to implement any of the methods and functions in Example 2. In yet another possible design, the processor is configured to execute a program or instruction to enable the multi-link communication device to implement any of the methods and functions in Example 3.

[0132] It should be noted that the memory may be included in the processor, or may be a storage unit external to the processor and coupled to the processor.

[0133] The embodiment of the present application further provides a processor, which is coupled to a memory and is used to execute any method and function involving the first multi-link device or the third multi-link device in any of the above embodiments.

[0134] The embodiment of the present application further provides a computer program product comprising instructions, which, when executed on a computer, enables the computer to execute any method and function involving the first multi-link device or the third multi-link device in any of the above embodiments.

[0135] An embodiment of the present application further provides an apparatus for executing any method and function involving the first multi-link device or the third multi-link device in any of the above embodiments.

[0136] An embodiment of the present application further provides a wireless communication system, which includes at least one first multi-link device and a third multi-link device involved in any one of the above-mentioned second embodiments.

[0137] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from one website, computer, server or data center to another website, computer, server or data center via a wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) method. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more available media integrations. The available medium can be a magnetic medium (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., a solid state disk (SSD)).

Claims

1. A multi-link communication method, characterized in that: Applicable to a first multi-link device, comprising: Sending a first physical layer protocol data unit (PPDU) to a second multi-link device on the first link; A second PPDU is sent to the second multi-link device on a second link, wherein the first PPDU and the second PPDU are sent simultaneously, and an end time of the second PPDU is aligned with an end time of the first PPDU.

2. The method according to claim 1, characterized in that The first PPDU and the second PPDU are sent simultaneously, including: a non-empty intersection exists between a transmission time of the first PPDU and a transmission time of the second PPDU.

3. The method according to claim 1 or 2, characterized in that The first PPDU and the second PPDU are received simultaneously.

4. The method according to claim 1 or 2, characterized in that The second multi-link device does not support simultaneous transmission and reception.

5. The method according to claim 1 or 2, characterized in that The end time of the second PPDU is aligned with the end time of the first PPDU, including: the end time of the second PPDU is not later than the end time of the first PPDU.

6. The method according to claim 1 or 2, characterized in that The method further comprises: receiving, on the first link, first information from the second multi-link device in response to the first PPDU; Second information in response to the second PPDU is received from the second multi-link device on the second link, wherein a duration of the second information is the same as a duration of the first information.

7. The method according to claim 6, characterized in that The time interval between the first information and the first PPDU is a preset time interval, and the time interval between the second information and the second PPDU is the preset time interval.

8. The method according to claim 6 or 7, characterized in that The first information and the second information are respectively block acknowledgements BA; or, the first information and the second information are respectively ACK.

9. The method according to claim 1 or 2, characterized in that The first PPDU and / or the second PPDU is a multi-user PPDU.

10. The method according to claim 1 or 2, characterized in that The first PPDU includes an uplink and downlink indication, where the uplink and downlink indication is used to indicate a transmission direction of the first PPDU, where the transmission direction includes uplink or downlink.

11. The method according to claim 1 or 2, characterized in that The first multi-link device is a multi-link access point, and the second multi-link device is a multi-link station.

12. A multi-link communication method, characterized in that: Applicable to a second multi-link device, comprising: receiving a first physical layer protocol data unit (PPDU) from a first multi-link device on a first link; A second PPDU is received from the first multi-link device on a second link, wherein the first PPDU and the second PPDU are received simultaneously, and an end time of the second PPDU is aligned with an end time of the first PPDU.

13. The method according to claim 12, characterized in that The first PPDU and the second PPDU are received simultaneously, including: a non-empty intersection exists between a transmission time of the first PPDU and a transmission time of the second PPDU.

14. The method according to claim 12 or 13, characterized in that The first PPDU and the second PPDU are sent simultaneously.

15. The method according to claim 12 or 13, characterized in that The second multi-link device does not support simultaneous transmission and reception.

16. The method according to claim 12 or 13, characterized in that The end time of the second PPDU is aligned with the end time of the first PPDU, including: the end time of the second PPDU is not later than the end time of the first PPDU.

17. The method according to claim 12 or 13, characterized in that The method further comprises: sending, on the first link, first information in response to the first PPDU to the first multi-link device; Second information in response to the second PPDU is sent to the second multi-link device on the second link, wherein a duration of the second information is the same as a duration of the first information.

18. The method according to claim 17, characterized in that The time interval between the first information and the first PPDU is a preset time interval, and the time interval between the second information and the second PPDU is the preset time interval.

19. The method according to claim 17 or 18, characterized in that The first information and the second information are respectively block acknowledgements BA; or, the first information and the second information are respectively ACK.

20. The method according to claim 12 or 13, characterized in that The first PPDU and / or the second PPDU is a multi-user PPDU.

21. The method according to claim 12 or 13, characterized in that The first PPDU includes an uplink and downlink indication, where the uplink and downlink indication is used to indicate a transmission direction of the first PPDU, where the transmission direction includes uplink or downlink.

22. The method according to claim 12 or 13, characterized in that The first multi-link device is a multi-link access point, and the second multi-link device is a multi-link station.

23. A communication device comprising at least one processor and a memory, wherein the memory is used to store instructions, characterized in that: When the instructions are executed by the at least one processor, the communication device is caused to perform the method according to any one of claims 1 to 11.

24. A communication device comprising at least one processor and a memory, wherein the memory is used to store instructions, characterized in that: When the instructions are executed by the at least one processor, the communication device is caused to perform the method according to any one of claims 12 to 22.

25. A computer-readable storage medium, characterized in that The computer-readable storage medium comprises instructions for implementing the method according to any one of claims 1-22.

26. A computer program product, characterized in that When the method is executed on a computer, the computer can execute the method according to any one of claims 1 to 22.

27. A communication system, characterized in that: The communication system includes a first multi-link device and a second multi-link device, wherein the first multi-link device is configured to execute the method according to any one of claims 1 to 11, and the second multi-link device is configured to execute the method according to any one of claims 12 to 22.

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