Multi-link communication method and apparatus

Abstract

An embodiment of the present application discloses a multi-link communication method and related devices. In a scenario where simultaneous multi-link transceiver is not supported, a multi-link device first sends a first physical layer protocol data unit (PPDU) on a first link; then sends a second PPDU on a second link by competing for a channel, and the end time of the second PPDU is not later than the end time of the first PPDU. This method can not only ensure the fairness of multi-link access, but also reduce the idle rate of multi-links.

Description

Technical Field

[0001] This application relates to the field of communication technologies, and in particular, to multi-link communication methods, apparatuses, and systems. Background Art

[0002] To significantly improve the service transmission rate of a Wireless Local Area Networks (WLAN) system, the Institute of Electrical and Electronics Engineers (IEEE) 802.11ax standard further adopts Orthogonal Frequency Division Multiple Access (OFDMA) technology on the basis of the existing Orthogonal Frequency Division Multiplexing (OFDM) technology. The 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 - 7125 MHz (this frequency band is called 6 GHz), the operating frequency band of the WLAN system expands from 2.4 GHz and 5 GHz to 2.4 GHz, 5 GHz, and 6 GHz.

[0003] A device that can operate on multiple frequency bands is called a multi-link device or a multi-band device. A multi-link device can support multi-link communication. For example, it supports simultaneous communication on the 2.4 GHz, 5 GHz, and 6 GHz frequency bands. Even when the number of antennas is limited, the multi-link device can switch between different frequency bands to select the best frequency band to ensure its communication quality. However, how to ensure the fairness of communication of multi-link devices operating on multiple links, reduce the idle rate of the links, and improve communication efficiency is crucial in a system that supports multi-link communication. Summary of the Invention

[0004] Embodiments of this application provide multi-link communication methods, apparatuses, and systems to ensure the fairness of communication of multi-link devices operating on multiple links, reduce the idle rate of the links, and improve communication efficiency.

[0005] The first aspect provides a multi-link communication method applied to a multi-link device. The multi-link device operates on multiple links, and the multiple links include 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 includes: the multi-link device sends a first physical layer protocol data unit (PPDU) on the first link; the multi-link device sends a second PPDU on the second link by competing for the channel, where the end time of the second PPDU is not 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 not earlier than the start time of the first PPDU, including being later than or equal to. The multi-link device first sends a PPDU on the first link, and then separately competes for the channel on the second link and then sends a PPDU. The multi-link device independently competes for the channel on multiple links. The link that competes for the channel first sends a message packet first, and the link that competes for the channel later sends a message packet later, which can not only ensure the fairness of multi-link access, but also reduce the idle rate of multi-links and improve the frequency efficiency.

[0006] 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 simultaneously sending a physical layer protocol data unit of a first bandwidth on the first link and receiving a physical layer protocol data unit of a second bandwidth on the second link, and / or, the multi-link device does not support simultaneously receiving a physical layer protocol data unit of a first bandwidth on the first link and sending a physical layer protocol data unit of a second bandwidth on the second link. The "simultaneously" here means that there is a non-empty intersection in time between the PPDU of the first bandwidth and the PPDU of the second bandwidth.

[0007] In a possible design, the first PPDU includes an uplink / downlink indication, and the uplink / downlink indication is used to indicate the transmission direction of the first PPDU. The transmission direction includes uplink or downlink. Based on the uplink / downlink indication, other devices can determine what type the multi-link device that sends the first PPDU belongs to. Optionally, if it is uplink, the multi-link device that sends the first PPDU is a multi-link station; if it is downlink, the multi-link device that sends the first PPDU is a multi-link access point.

[0008] In a 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 that of the second TXOP. That is to say, the second TXOP indicated in the second PPDU can be set according to the first TXOP indicated in the first PPDU. 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.

[0009] In a second aspect, another multi-link communication method is provided, which is applied to a multi-link device. The multi-link device operates on multiple links, and the multiple links include a first link and a second link. The multi-link device does not support simultaneously transmitting and receiving PPDUs on the first link and the second link. The method includes: the first multi-link device transmits a first physical layer protocol data unit (PPDU) on the first link; after a preset time interval, the first multi-link device receives, on the first link, a second PPDU from a second device in response to the first PPDU; the first multi-link device receives, on the second link, a third PPDU transmitted by a third multi-link device on the second link, and the end time of the third PPDU is not later than the end time of the second PPDU, where "not later than" includes being earlier than or equal to; optionally, the start time of the third PPDU is not earlier than the end time of the first PPDU, where "not earlier than" includes being later than or equal to. Optionally, the first multi-link device and the third multi-link device belong to the same basic service set (BSS). By using the above method, when other multi-link devices receive the PPDU transmitted by the first multi-link device on the first link, they can start preempting the channel (including actions such as listening and backoff) on another link at the end of the PPDU to transmit the PPDU, which can not only ensure the fairness of multi-link access but also reduce the idle rate of the multi-link and improve the frequency efficiency.

[0010] The multi-link device does not support simultaneously transmitting and receiving on the first link and the second link, including: the multi-link device does not support simultaneously transmitting a physical layer protocol data unit with a first bandwidth on the first link and receiving a physical layer protocol data unit with a second bandwidth on the second link, and / or, the multi-link device does not support simultaneously receiving a physical layer protocol data unit with a first bandwidth on the first link and transmitting a physical layer protocol data unit with a second bandwidth on the second link. The "simultaneously" here means that there is a non-empty intersection in time between the PPDU with the first bandwidth and the PPDU with the second bandwidth.

[0011] In a possible design, the first PPDU includes transmission duration information for indicating the transmission duration of the second PPDU; or, the physical layer preamble of the second PPDU includes the transmission duration information for indicating the transmission duration of the second PPDU. According to the transmission duration information, the third multi-link device can obtain the transmission duration of the second PPDU, and thus can determine the transmission duration and end time of the third PPDU based on the transmission duration of the second PPDU, so as to avoid the first multi-link device from simultaneously transmitting and receiving on the first link and the second link.

[0012] In a possible design, the third PPDU includes third TXOP duration information for indicating the third TXOP duration, and the third TXOP duration does not exceed the minimum value or the earliest end value of the first TXOP duration indicated by the first TXOP duration information in the first PPDU and a second duration; 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 acknowledgment information in response to the second PPDU.

[0013] In a possible design, the first PPDU includes data information and the second PPDU includes acknowledgment information; or, the first PPDU includes trigger information and the second PPDU includes uplink data. Of course, the first PPDU may further include other information.

[0014] A third aspect provides another multi-link communication method, which is applied to a multi-link device operating on multiple links, where the multiple links include a first link and a second link. The method includes: the third multi-link device obtains a first PPDU transmitted by the first multi-link device on the first link; at or after the end time of the first PPDU, the third multi-link device sends a third PPDU on the second link, and the end time of the third PPDU is not later than the end time of the second PPDU, where the second PPDU is a response to the first PPDU sent on the first link. "Not later than" includes earlier than or equal to. The second PPDU is a response to the first PPDU sent by the first multi-link device on the first link. The start time of the third PPDU is not earlier than the end time of the first PPDU, and "not earlier than" includes later than or equal to. Optionally, the third multi-link device can send the third PPDU by competing for the channel. The first multi-link device and the third multi-link device belong to the same basic service set BSS.

[0015] 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 preempt the channel (including actions such as listening and backoff) on another link at the end of the PPDU, so as to send the PPDU, which can not only ensure the fairness of multi-link access, but also reduce the idle rate of the multi-link and improve the frequency efficiency.

[0016] In a possible design, on the second link, a third PPDU is sent through a contention channel, including: a third multi-link device sending the third PPDU through the contention channel on the second link at or after the end time of the first PPDU.

[0017] In a possible design, the first PPDU includes transmission duration information for indicating the transmission duration of the second PPDU; or, the physical layer preamble of the second PPDU includes the transmission duration information for indicating the transmission duration of the second PPDU. According to the transmission duration information, the third multi-link device can obtain the transmission duration of the second PPDU, and thus can determine the transmission duration and end time of the third PPDU according to the transmission duration of the second PPDU, so as to avoid the first multi-link device from simultaneously transmitting and receiving on the first link and the second link.

[0018] In a possible design, the third PPDU includes third TXOP duration information for indicating the third TXOP duration, and the third TXOP duration does not exceed the minimum value or the earliest end value of the first TXOP duration indicated by the first TXOP duration information in the first PPDU and a second duration; where 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 acknowledgment information in response to the second PPDU.

[0019] In a possible design, the first PPDU includes data information and the second PPDU includes acknowledgment 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.

[0020] In a fourth aspect, a multi-link communication device is provided, which operates on multiple links, and the multiple links include a first link and a second link. The device includes: a first sending module for sending a first physical layer protocol data unit (PPDU) on the first link; a second sending module for sending a second PPDU through a contention channel on the second link, where the end time of the second PPDU is not 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 not earlier than the start time of the first PPDU, including later than or equal to. The multi-link device first sends a PPDU on the first link, and then separately performs channel contention on the second link and then sends the PPDU. The multi-link device performs independent channel contention on multiple links. The link that contends for the channel first sends a message packet, and the link that contends for the channel later sends a message packet, which can not only ensure the fairness of multi-link access, but also reduce the idle rate of multi-links and improve the frequency efficiency.

[0021] In a possible design, the device further includes a first processing module and a second processing module. The first processing module is used to generate a first PPDU, and the second processing module is used to generate a second PPDU. The first processing module and the second processing module may also be a single processing module.

[0022] In a fifth aspect, a multi-link communication device is provided, which operates on multiple links. The multiple links include: a first link and a second link, and the device includes:

[0023] A first transceiver module, configured to send a first physical layer protocol data unit (PPDU) on the first link;

[0024] The first transceiver module is configured to, after a preset time interval, the first multi-link device receives, on the first link, a second PPDU from a second device in response to the first PPDU;

[0025] A second transceiver module, configured to receive, on the second link, a third PPDU sent by a third multi-link device on the second link, where the end time of the third PPDU is not later than the end time of the second PPDU.

[0026] In a possible design, the first transceiver module further includes a first sending module and a first receiving module. The second transceiver module further includes a second sending module and a second receiving module. A transceiver module can support the multi-link communication device to operate on one link.

[0027] In a sixth aspect, a multi-link communication device is provided. The device includes:

[0028] A first transceiver module, which obtains a first PPDU transmitted by a first multi-link device on a first link;

[0029] A second transceiver module, configured to send a third PPDU on the second link, where the end time of the third PPDU is not later than the end time of a second PPDU, and the second PPDU is sent on the first link and in response to the first PPDU.

[0030] In a possible design, the first transceiver module further includes a first sending module and a first receiving module. The second transceiver module further includes a second sending module and a second receiving module. A transceiver module can support the multi-link communication device to operate on one link.

[0031] Combined with the fifth aspect or the sixth aspect, in a possible implementation, the end time of the third PPDU is not later than the end time of the second PPDU, where "not later than" includes being earlier than or equal to; optionally, the start time of the third PPDU is not earlier than the end time of the first PPDU, where "not earlier than" includes being later than or equal to. 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.

[0032] The seventh aspect provides a multi-link communication device, including: a processor and a memory; the memory is used to store computer instructions, and when the processor executes the instructions, the communication device is enabled to execute the method described in any of the above aspects. The communication device can be the multi-link device or the chip in the multi-link device in the first aspect above, or can be the first multi-link device or the chip therein in the second aspect above; or, the communication device can be the multi-link device or the chip therein in the third aspect above.

[0033] The eighth aspect provides a communication device, including: a processor; the processor is used to be coupled with a memory, and after reading the instructions in the memory, execute the method described in any of the above aspects according to the instructions. The communication device can be the multi-link device or the chip in the multi-link device in the first aspect above, or can be the first multi-link device or the chip therein in the second aspect above; or, the communication device can be the multi-link device or the chip therein in the third aspect above.

[0034] The ninth aspect provides a computer-readable storage medium, in which instructions are stored, and when it runs on a computer, the computer can execute the method described in any of the above aspects.

[0035] The tenth aspect provides a computer program product containing instructions, and when it runs on a computer, the computer can execute the method described in any of the above aspects. Description of the Drawings

[0036] Figure 1 It is a schematic diagram of a multi-link communication scenario;

[0037] Figure 2 It is a timing schematic diagram of multi-link communication for synchronous access to multiple links provided by an embodiment of the present application;

[0038] Figure 3 It is a timing schematic diagram of single-link communication for accessing a single link provided by an embodiment of the present application;

[0039] Figure 4 It is a timing schematic diagram of multi-link communication provided by an embodiment of the present applicationFigure 1 ;

[0040] Figure 5 Another timing schematic of multi-link communication provided by an embodiment of the present application Figure 2 ;

[0041] Figure 6 Another timing schematic of multi-link communication provided by an embodiment of the present application Figure 3 ;

[0042] Figure 7 Another timing schematic of multi-link communication provided by an embodiment of the present application Figure 4 ;

[0043] Figure 8 Another timing schematic of multi-link communication provided by an embodiment of the present application Figure 5 ;

[0044] Figure 9 A structural schematic of a multi-link communication device provided by an embodiment of the present application Figure 1 ;

[0045] Figure 10 Another structural schematic of a multi-link communication device provided by an embodiment of the present application Figure 2 ;

[0046] Figure 11 Another structural schematic of a multi-link communication device provided by an embodiment of the present application Figure 3 . Detailed implementation manners

[0047] The embodiments of the present application will be described below with reference to the accompanying drawings in the embodiments of the present application. The network architecture and service scenarios described in the embodiments of the present application are for more clearly illustrating 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. Those of ordinary skill in the art can know that with the evolution of the network architecture and the emergence of new service scenarios, the technical solutions provided by the embodiments of the present application are equally applicable to similar technical problems.

[0048] The solution of the embodiment of the present application is applicable to communication between at least two multi-link devices. A multi-link device is a device that can work on multiple links. The multiple links are multiple links that are different in the frequency domain. The multiple links can be multiple different frequency bands respectively, and the multiple links can also be different channels on the same frequency band. Optionally, in a WLAN system, the frequency bands may include 2.4 GHz, 5 GHz, 6 GHz, etc., and the bandwidth of a channel on a frequency band can be 20 MHz, 40 MHz, 80 MHz, 160 MHz, 320 MHz, etc., and the basic unit is 20 MHz. Subsequently, the channel bandwidth may be further expanded, and the basic unit may also be 40 MHz or larger.

[0049] A multi-link device includes multiple stations (STA), where one station corresponds to one link and operates on the corresponding link. Here, the station can be a non-access point station or an access point station. Figure 1 An exemplary communication scenario of an embodiment of the present application is shown. As Figure 1 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 operate on multiple links (e.g., link 1, link 2,... link n). Here, one station operates on one link, and the multiple stations can also belong to a multi-link entity, and this link entity shares a media access control (MAC) service access point (SAP). It can be understood that Figure 1 the number of multi-link devices, the number of stations in the multi-link device, and the number of links included in the shown communication scenario are only exemplary and do not limit the present application.

[0050] In one example, the multi-link device is a multi-link access point, including multiple access point (AP) stations, where one access point corresponds to one link and operates on the corresponding link. In another example, the multi-link device is a multi-link station, including multiple non-access point stations, where one non-access point station corresponds to one link and operates on the corresponding link. In another example, the multi-link device can include both access point stations and non-access point stations. Therefore, the solution of the embodiment of the present application can be applied to the communication between a multi-link access point and a multi-link station, can also be applied to the communication between at least two multi-link access points, can also be applied to the communication between at least two multi-link stations, and of course can also be applied to the communication between multi-link devices including both access point stations and non-access point stations.

[0051] The access point AP included in the multi-link device can be a communication device with wireless communication capabilities, a communication device that provides services for non-access point stations, and supports mobile users to access the wired network. It can be deployed indoors in homes, buildings, and campuses, with a typical coverage radius ranging from dozens of meters to hundreds of meters. Of course, it can also be deployed outdoors. The AP is equivalent to a bridge connecting the wired network and the wireless network. Its main function is to connect each wireless station together and then connect the wireless network to the Ethernet. The AP can support multiple communication protocols. For example, cellular communication protocols and WLAN communication protocols, etc. Optionally, the AP can be a device with a wireless-fidelity (WiFi) chip and can support the WLAN communication protocol. For example, the AP can support the next generation of 802.11ax. Optionally, the multi-link AP can also support 802.11ax, 802.11ac, 802.11n, 802.11g, 802.11b, and 802.11a, etc.

[0052] The stations included in the multi-link device can be communication devices with wireless communication capabilities and can support multiple communication protocols. For example, cellular communication protocols and WLAN communication protocols, etc. Optionally, the STA can be a device with a wireless-fidelity (WiFi) chip and can support the WLAN communication protocol. For example, the 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. The STA can also be a terminal device, such as a mobile phone supporting WiFi communication function, a tablet computer supporting WiFi communication function, a set-top box supporting WiFi communication function, a smart TV supporting WiFi communication function, a smart wearable device supporting WiFi communication function, a vehicle-mounted communication device supporting WiFi communication function, and a computer supporting WiFi communication function, etc.

[0053] For a multi-link device operating on multiple links, usually due to energy leakage between the links and insufficient processing capabilities for simultaneous transmission and reception of the multi-link device, the multi-link device cannot support simultaneous transmission and reception on multiple links. Even if the multi-link device allows simultaneous transmission and reception on multiple links, it will also cause interference to the data packets received on one link by the data packets sent on another link, resulting in poor communication quality. Therefore, in the case where the multi-link device cannot perform simultaneous transmission and reception on 2 or more links, multiple solutions have been proposed.

[0054] One solution is the synchronous transmission method. The main principle is to independently compete for the channel and simultaneously access the channel through multiple links. Additionally, the data packets transmitted on multiple links occupy the same time duration (if necessary, it can be achieved by filling garbage information bits). One implementation of simultaneously accessing the channel includes: when the multi-link device competes for the channel on one link, for example, by using enhanced distributed channel access (EDCA) and backing off to 0 to seize the transmission opportunity, the multi-link device checks whether the point coordination function interframe space (PIFS) time is idle on other links. If it is idle, multiple links transmit simultaneously. If it is busy, the multi-link device can choose to transmit on a single link or choose not to transmit. As Figure 2 shown, the AP competes for the channel on Link 1 through EDCA, backs off the backoff number to 0, and then checks the PIFS time on Link 2. If it is idle, physical protocol data units (PPDUs) are transmitted simultaneously on both links at this time. The PPDUs transmitted on these two links have the same transmission duration. Then, after a fixed interval, such as the Short interframe space (SIFS) defined in 802.11, the multi-link device receives the acknowledgment frames of the station responses on both links, Figure 2 taking Block Ack (BA) as an example in the figure. Of course, it can also be an acknowledge (Ack) frame. By using the synchronous transmission method, the problem of simultaneous sending and receiving on multiple links can be avoided. However, in this solution, the multi-link device first competes for the channel on one link and then transmits data packets on other links where the PIFS time is idle. However, conventional listening and backoff are not performed on other links. Instead, it checks whether the PIFS is busy, resulting in the stations in the multi-link device having priority access to the channel on other links, which is unfair to other stations.

[0055] Another solution is to prohibit simultaneous sending and receiving. The stations in the multi-link device only transmit data packets on one of the links. To avoid simultaneous sending and receiving, that is, the multi-link device needs to prohibit the receiving end of data packets and other stations within the basic service set (BSS) from competing for the channel to transmit data on the other link, that is, stop their backoff. There are multiple scenarios for the multi-link device to transmit on one link. For example, the multi-link device only has data to transmit on one of the links. Another example is that the multi-link device first competes for the channel on one link, but at this time the other links are busy. As Figure 3As shown, the AP in the multi-link device competes for the channel on link 1 and sends a physical protocol data unit (PPDU) to site A. If site A is a multi-link site, then when site A receives the data packet sent by the AP, it needs to 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, then it starts backing off. Similarly, if the multi-link device in this BSS hears that the AP sends a data packet on link 1, it also needs to stop backing off on other links. The method of prohibiting simultaneous transmission and reception requires stopping the backing off of multi-link sites in this BSS on links where data packets are not received. Although this solves the problem of preventing sites from transmitting and receiving at the same time, it wastes idle link spectrum resources.

[0056] Therefore, an 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.

[0057] Embodiment 1

[0058] In the scenario where simultaneous multi-link transmission and reception is not supported, it is proposed that multiple links of a multi-link site compete for channels independently, and the one that seizes the channel link first sends the PPDU first, and the one that seizes the channel link later sends the PPDU later, but at this time, the end time of the PPDU sent later must be no later than the end time of the PPDU sent earlier, for example, the end time of the PPDU sent later is the same as the end time of the PPDU sent earlier, that is, 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.

[0059] An embodiment of the present application provides a multi-link communication method, which can be applied to a multi-link device. The method includes:

[0060] S101, a multi-link device sends a first physical layer protocol data unit PPDU on a first link;

[0061] The multi-link device can operate on at least two links, where the at least two links include a first link and a second link. Among them, the multi-link device does not support simultaneously transmitting and receiving PPDUs on the first link and the second link. The first PPDU can be sent by a station operating on the first link in the multi-link device. In one example, the multi-link device not supporting simultaneously transmitting and receiving PPDUs on the first link and the second link includes: the multi-link device does not support simultaneously sending a physical layer protocol data unit of a first bandwidth on the first link and receiving a physical layer protocol data unit of a second bandwidth on the second link, and / or, the multi-link device does not support simultaneously receiving a physical layer protocol data unit of a first bandwidth on the first link and sending a physical layer protocol data unit of a second bandwidth on the second link. The "simultaneously" here means that there is a non-empty intersection in time between the PPDU of the first bandwidth and the PPDU 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.

[0062] In addition, the "simultaneous transmission and reception" in this application does not mean that there is no difference in time at all. "Simultaneous transmission and reception" can mean that there is a non-empty intersection in time between 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. For example, if the duration of the PPDU of the first bandwidth is T1 = E1 - S1, with the start and end times being [S1, E1], and the duration of the PPDU of the second bandwidth is T2 = E2 - S2, with the start and end times being [S2, E2], then there is a non-empty intersection between [S1, E1] and [S2, E2].

[0063] Optionally, the multi-link device can send the first PPDU by competing for the channel on the first link. The way of competing for the channel can be EDCA or multi-user EDCA (MU EDCA) specified by the 802.11 protocol, or traditional ways of competing for the channel, etc. In one example, the competition method of EDCA includes: the multi-link device first listens for an AIFS time, then starts to back off. It starts sending data only when the back-off reaches 0. During the back-off process, if the channel is busy, the back-off is suspended or stopped. When the channel is idle again next time, it competes for the channel again based on the number of back-offs suspended last time, including processes such as AIFS time listening and back-off. Optionally, the multi-link device can also have preempted the channel on the first link and send the first PPDU on the first link within the already preempted transmission opportunity (TXOP), where the first PPDU is a data packet within this TXOP. Optionally, the first PPDU can include a data frame, a management frame, or a control frame, etc., or an aggregation packet of multiple frames.

[0064] S102, The multi-link device sends a second PPDU on the second link by competing for the channel, where the end time of the second PPDU is not later than the end time of the first PPDU;

[0065] The multi-link device performs channel contention on the second link. After contending for the channel, it sends a second PPDU on the second link. The transmission time of the second PPDU is not earlier than (equal to or later than) the first PPDU. The second PPDU can be sent by a station operating on the second link in the multi-link device. The channel contention method of the multi-link device on the second link can also be EDCA specified by the 802.11 protocol or multi-user EDCA (MU EDCA), or a traditional channel contention method, etc. Optionally, the second PPDU can include a data frame, a management frame, a control frame, etc., or an aggregation packet of multiple frames. Optionally, the multi-link device can also send the second PPDU within a TXOP without contending for the channel.

[0066] In one implementation, the end time of the second PPDU is not 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 and the second PPDU are aligned, the situation where the multi-link device may simultaneously transmit and receive is avoided. It should be noted that since the multi-link device knows the duration of the first PPDU, when sending the second PPDU, it can accurately determine the duration of the second PPDU according to the duration of the first PPDU, so that the end time of the second PPDU is not later than the end time of the first PPDU. In another way, the multi-link device can also obtain the transmission duration of the first PPDU by listening to the length field in the L-SIG field of the traditional preamble of the first PPDU sent first.

[0067] Optionally, the length of the TXOP indicated by the second PPDU can be set to be the same as the duration of the TXOP indicated by the first PPDU. Among them, the information indicating the TXOP duration can 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, and the first TXOP length duration information indicates the duration of the first TXOP. The second PPDU includes second TXOP duration information, and the second TXOP duration information indicates the duration of the second TXOP. 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 in 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 in the duration field of the MAC header of the second PPDU.

[0068] Before performing step S101 and step S102, when the station associates with the AP or listens to the beacon frame sent by the AP, it can obtain the capability information of the multi-link AP to know which links the multi-link AP cannot support for simultaneous transmission and reception, which links it can support for simultaneous transmission and reception. Further, it can know which links of the multi-link AP cannot simultaneously transmit and receive a PPDU of the first bandwidth and a PPDU of the second bandwidth, where the bandwidth of the PPDU is a factor determining the self-interference of the multi-link. This capability information can be implicit indication information or explicit indication information. The specific indication method is not specifically limited in the embodiments of the present application.

[0069] Optionally, the method further includes:

[0070] S103, the multi-link device receives first acknowledgment information in response to the first PPDU on the first link;

[0071] S104, the multi-link device receives second acknowledgment information in response to the second PPDU on the second link.

[0072] The first acknowledgment information is sent by the destination receiver of the first PPDU, and the second acknowledgment information is sent by the destination receiver of the second PPDU. The destination receivers of the first PPDU and the second PPDU can be the multi-link device or not the multi-link device, but the device operating on this link, such as an AP or a non-AP STA. The destination receiver of the first PPDU can be in the same basic service set (BSS) as the first multi-link device, and the destination receiver of the second PPDU is 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 can be the same destination receiver or different destination receivers. For the case where the destination receivers of the first PPDU and the second PPDU are the same destination receiver, then this receiver is the multi-link device, which is not limited in the present application. Optionally, the acknowledgment information is sent after a preset time interval of the PPDU, and the preset time interval can be SIFS. Optionally, the first acknowledgment information and the second block acknowledgment information can be block acknowledgment BA or ACK. Optionally, the durations of the first acknowledgment information and the second acknowledgment information are the same.

[0073] In one implementation, the multi-link device that sends the first PPDU can be a multi-link station, and the destination receiver of the first PPDU can be an access point; in another implementation, the multi-link device that sends the first PPDU can be a multi-link access point, and the destination receiver of the first PPDU can be a station. To let the destination receiver know what role of device sends the first PPDU, optionally, the physical layer preamble of the first PPDU includes an uplink / downlink indication (which can also be denoted as uplink / downlink indication), and the uplink / downlink indication is used to indicate the transmission direction of the first PPDU. The transmission direction includes uplink or downlink. Among them, the PPDU sent from the AP in the multi-link device to the station belongs to downlink, and the PPDU sent from the station in the multi-link device to the AP belongs to uplink. It should be noted that if the sending end 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 this BSS cannot compete for the channel on other links (such as the second link), and cannot send PPDU to the multi-link AP on the second link, so as to avoid the situation of simultaneous sending and receiving at the multi-link AP end. If the sending 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 this BSS can compete for the channel on other links (such as the second link), and then send the second PPDU to the access point in this BSS. The sending time of the second PPDU is equal to or later than the sending time of the first PPDU, but the end time of the second PPDU is not later than the end time of the first PPDU. In one implementation, the end time of the second PPDU is the same as the end time of the first PPDU. It can be understood that, of course, for the case of downlink transmission, the first PPDU can also be sent by the access point in the multi-link device, and the destination receiver of the first PPDU is the station; for the case of uplink transmission, the first PPDU can also be sent by the station in the multi-link device, and the destination receiver of the first PPDU is the access point.

[0074] For example, Figure 4 Fig. shows a case of downlink transmission. The multi-link AP competes for the channel on Link 1 and sends PPDU1 to Station A, and then competes for the channel on Link 2 and sends PPDU2 to Station B. The start time of PPDU2 is not earlier than (equal to or later than) the start time of PPDU1. Figure 4 Fig. shows the case of equality, and the end time of PPDU2 is aligned with the end time of PPDU1. Station A and Station B respectively reply with acknowledgment information, such as BA, on the channels of Link 1 and Link 2. This embodiment can also be extended to the AP sending multi-user data packets to multiple stations on Link 1 and Link 2. For example, through 802.11ax HE MU PPDU, it can be in the form of OFDMA, or in the form of providing MU-MIMO or a mixture of them.

[0075] For example, Figure 5 A scenario of uplink transmission is shown. The multi-link STA sends PPDU1 to access point AP1 on link 1, and then competes for the channel on link 2 and sends PPDU2 to access point AP2. The start time of PPDU2 is not earlier than the start time of PPDU1, including equal to and later than. Figure 5 The case of equality is shown in. The end time of PPDU2 is aligned with the end time of PPDU1. AP1 and AP2 respectively send acknowledgment information on the channels on link 1 and link 2. Of course, in Figure 5 In the shown scenario, AP1 and AP2 can also be access points operating on different links in the same multi-link access point, or access points in different multi-link devices, etc.

[0076] For the convenience of description, the multi-link device in steps S101 and S102 is denoted 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 other multi-link stations can send other message packets to another station (non-AP STA) during the transmission time of the first PPDU sent by the first multi-link device. The specific implementation method is as follows:

[0077] 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, other multi-link stations within this BSS can perform TDLS message packet transmission through channel competition on other links (the second link). The transmission time of the TDLS message packet is equal to or later than the transmission time of the first PPDU. When the receiving object of the TDLS message packet is the receiving object of the first PPDU, the end time of the TDLS message packet mentioned in this embodiment needs to be 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 can be no restrictions.

[0078] Second Embodiment: If the first multi-link device is a multi-link station, that is, the first PPDU is for uplink transmission. When the multi-link station first sends the first PPDU on the first link, at this time, other multi-link stations within this BSS can transmit TDLS message packets through channel contention on other links (the second link), but the receiving object of the TDLS message packet cannot be the first multi-link device that sends the first PPDU, that is, the multi-link station. In other cases, there are no restrictions.

[0079] Adopting the solution of the embodiment of the present application, the multi-link device competes for channels independently 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 multi-links and improve the frequency efficiency.

[0080] Embodiment 2 provides another multi-link communication method, which can be applied to a multi-link device. The method includes:

[0081] S201, the first multi-link device sends a first physical layer protocol data unit PPDU on the first link;

[0082] Referring to the description in the foregoing step S101, it will not be elaborated here. Optionally, the first multi-link device does not support simultaneous transceiver on the first link and the second link.

[0083] S202, after a preset time interval for the second device to receive the first PPDU on the first link, the second device sends a second PPDU in response to the first PPDU;

[0084] Optionally, the preset time interval can be SIFS.

[0085] S203, after the preset time interval, the first multi-link device receives the second PPDU in response to the first PPDU on the first link;

[0086] Correspondingly, the destination receiver of the first PPDU is the second device. After receiving the first PPDU, the second device will send a second PPDU in response to the first PPDU on the first link after the preset time interval. The second device can be a device that only operates on a single link (i.e., the first link), or can support multi-link communication and belongs to the same BSS as the first multi-link device. The preset time interval is agreed by the protocol and can be SIFS. The first PPDU can include a data frame, a management frame, or a control frame, or can also include an aggregation of multiple frames.

[0087] The first multi-link device can be a multi-link AP and a multi-link STA. In one implementation, the first PPDU includes data information, and the second PPDU includes acknowledgment information in response to the data information. If the first PPDU is a downlink, the first multi-link device is a multi-link AP; if the first PPDU is an 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, and the interpretation of the uplink / downlink indication is as described in the foregoing Embodiment 1 and will not be elaborated here.

[0088] 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. "Obtain" can be receive or identify. Optionally, the third multi-link device can also obtain the 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, so as to determine the transmission duration or end time of the third PPDU to be sent according to the end time or transmission duration of the second PPDU. For specific how to obtain, see the description below.

[0089] In S205, the third multi-link device sends the third PPDU on the second link, and the end time of the third PPDU is not later than the end time of the second PPDU.

[0090] Optionally, the third multi-link device may also send a third PPDU by competing for a channel. Specifically, a third multi-link device belonging to the same basic service set as the first multi-link device, after identifying or receiving the first PPDU and at or after the end time of the first PPDU, may send the third PPDU by competing for the channel on the second link. The transmission 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 a possible implementation, the end time of the third PPDU is the same as the end time of the second PPDU. However, the transmission time of the third PPDU shall 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 by competing for the channel on the second link at or after the end time of the first PPDU, so as to avoid the first multi-link device from simultaneously transmitting and receiving on the first link and the second link. In addition, when the third bandwidth of the third PPDU and the first bandwidth of the first PPDU satisfy a certain relationship, it is necessary to avoid the situation where the first link device sends the first PPDU on the first link and the second link receives the third PPDU with overlapping time (simultaneously transmitting and receiving); otherwise, the solution of the embodiments of the present application may not need to be adopted. The above relationship may 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 value.

[0091] Optionally, the third multi-link device may include a third multi-link station that is a non-intended receiver of the first PPDU and the intended receiver of the first PPDU, that is, the second device. After identifying or receiving the first PPDU, the third multi-link device will independently compete for the channel on other links (the second link), and send the third PPDU after competing for the channel. In one implementation, the third multi-link device within this BSS starts competing for the channel at or after the end time of the first PPDU, and starts sending the third PPDU after obtaining the channel transmission right. In an example, the method of identifying or receiving the first PPDU includes identifying the indication information of the preamble of the first PPDU, including but not limited to downlink / uplink indication information, the indication information in the MAC header of the first PPDU, such as the sending end MAC address, etc.

[0092] The PPDU sent by the multi-link device in this embodiment may be a single-user message packet sent to a single station, or a multi-user message packet sent to multiple stations (including OFDMA or MU-MIMO, or a mixed message packet thereof).

[0093] 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, and the end time of the third PPDU is not later than the end time of the second PPDU. In one implementation, the end time of the third PPDU is equal to the end time of the second PPDU.

[0094] 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 following are several implementation manners for the third multi-link device to determine the end time of the third PPDU:

[0095] The first implementation manner: The first PPDU sent by the first multi-link device carries length or time indication (or referred to as transmission duration information) for indicating the transmission duration of the second PPDU; the third multi-link device can determine the transmission duration of the second PPDU based on the transmission duration information in the first PPDU, and thus determine the transmission duration and / or end time of the third PPDU according to the transmission duration of the second PPDU.

[0096] The second implementation manner: The physical layer preamble of the second PPDU sent by the second device includes the transmission duration information for indicating the transmission duration of the second PPDU. For example, the transmission duration information is the length field in the traditional preamble L-SIG field. 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, and thus determine the transmission duration and / or end time of the third PPDU according to the transmission duration of the second PPDU.

[0097] Optionally, the transmission duration information carried by the first PPDU sent by the first multi-link device can also be used to indicate that the second PPDU starts to be sent at a fixed interval, such as the SIFS time, after the end of the first PPDU.

[0098] It should be noted that if the third multi-link device is the destination receiver of the first PPDU, that is, the second device, the second device itself knows the duration of the second PPDU sent, so the first and second implementation manners above can be not adopted to determine the transmission duration and / or end time of the third PPDU. For this case, the second device is a multi-link device. If the third multi-link device is another multi-link device other than the first multi-link device and the second device, the first and second implementation manners above can be adopted to determine the transmission duration and / or end time of the third PPDU. For this case, the second device can also be a device working only on a single link (i.e., the first link), or a multi-link device.

[0099] 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. Since the transmission time of the acknowledgment information is short, the transmission duration obtained by other multi-link devices in the BSS through the above method on other links is also short, where the other multi-link devices include devices other than the first multi-link device in the BSS, for example, the third multi-link device. To let other multi-link stations in the BSS know the transmission time length of the acknowledgment information, the message packet sent by the multi-link AP may carry the transmission duration information of the acknowledgment information in the MAC header. In one example, the transmission duration information may be a length field in bytes, and its function is similar to the length field in L-SIG in the traditional preamble. For example, other multi-link stations can determine based on the length that the transmission time = length field / 6 Mbps, so as to obtain the transmission duration of the third PPDU. Optionally, the length field can be carried in the length subfield included in the triggered response schedule (TRS) field in 802.11ax, and other subfields in the TRS field can be set to special values or reserved values. Of course, since the transmission time of the acknowledgment information is short and the transmission opportunities available to other devices are short, the protocol may prohibit transmission during this transmission time or may allow transmission during this transmission time. In addition, the second PPDU responded by the second device may further include other frames in addition to the acknowledgment information, and the first PPDU also needs to carry the transmission duration information, for example, carry the length indication information in the MAC header to indicate the transmission duration of the second PPDU.

[0100] For another example, when the first PPDU sent by the multi-link AP includes a trigger frame carrying trigger information, it may also include other aggregated frames. The trigger frame is used to schedule multi-user uplink OFDMA transmission, MU-MIMO transmission, or a hybrid transmission of OFDMA and MU-MIMO. At this time, the second PPDU based on the response of the trigger frame by multiple stations includes uplink data, such as data frames. At this time, the multi-link stations within this BSS obtain a longer transmission opportunity on other links through the above method. In another example, the trigger information included in the first PPDU may not be carried in a separate trigger frame, and the trigger information may also be carried in the MAC header of the MAC frame in the first PPDU. For example, the trigger information is carried in the TRS field of the PPDU that follows the 802.11ax standard. Further, the trigger frame sent by the multi-link AP includes a length indication for indicating the transmission time of the second PPDU. This length indication can be in units of time duration or in units of bytes. When in units of bytes, when the receiving end calculates the transmission time of the second PPDU using the length indication, it is obtained by dividing the number of bytes carried in the length field by 6 Mbps, rather than dividing by the actual rate of the second PPDU.

[0101] In addition, the third TXOP duration of the third PPDU sent by the third multi-link device within this BSS can be set according to the first TXOP duration of the first PPDU or the transmission duration of the second PPDU.

[0102] Optionally, the duration of the third TXOP of the third PPDU can be set to the minimum value or the earliest end value among the following two.

[0103] 1. The first TXOP duration of the first PPDU;

[0104] 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 the SIFS and the transmission duration of the response and the acknowledgment information of the second PPDU.

[0105] Thus, in one example, the third PPDU includes third TXOP duration information indicating the third TXOP duration, and the third TXOP duration does not exceed the minimum value or the earliest end value of the first TXOP duration indicated by the first TXOP duration information in the first PPDU and the second duration; 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 acknowledgment information in response to the second PPDU. Optionally, 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, and the third TXOP duration information is carried in the physical layer preamble of the third PPDU or the duration field of the MAC header of the third PPDU. The earliest end value refers to the earliest end time among the end times of each duration. The third TXOP duration not exceeding the earliest end value means that the end time value of the duration of the third TXOP does not exceed the earliest end value, and the third TXOP duration not exceeding the minimum value means that the duration of the third TXOP does not exceed the minimum duration.

[0106] The following uses several examples to briefly introduce the solutions of the embodiments of the present application.

[0107] For example, Figure 6 As shown, the multi-link AP successfully competes for the channel of link 1, sends PPDU1 containing a trigger frame, and schedules stations A1, A2, and A3 to send uplink multi-user data packets (PPDU2). The length field in the trigger frame indicates the transmission duration of the uplink multi-user data packet (PPDU2). After the third-party multi-link station STAB in this BSS receives PPDU1 sent by the multi-link AP1 on link 1, it starts competing for the channel of link 2 at the end of PPDU1, and then sends PPDU3. Figure 6 Lists two possible times for STAB to send PPDU3 on link 2, which may be earlier than or later than the start time of the uplink multi-user data packets (PPDU2) sent by the scheduled stations A1, A2, and A3. Of course, it can also be equal to ( Figure 6 (not shown). Of course, whether PPDU3 is earlier than or later than, or equal to the start time of the uplink multi-user data packets (PPDU2) sent by stations A1, A2, and A3 depends on the time when STAB seizes the channel on link 2. In addition, the end time of STAB sending PPDU3 on link 2 is the same as the end time of the uplink multi-user data packets sent by the scheduled stations A1, A2, and A3. Among them, stations A1, A2, and A3 may not be multi-link stations, and station B is a multi-link station. Of course, when stations A1, A2, and A3 are also multi-link stations, they can also compete for the channel on link 2, so as to send PPDU3.

[0108] For example, Figure 7As shown in the figure, the multi-link AP successfully competes for the channel of Link 1 and 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 acknowledgment information after the SIFS time. After receiving PPDU1 sent by the multi-link AP1 on Link 1, the third-party multi-link station STAB within 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 may not be multi-link stations, and station B is a multi-link station. Of course, when stations A1, A2, and A3 are also multi-link stations, they can also compete for the channel on Link 2 to send PPDU3.

[0109] For example, Figure 8 As shown in the figure, the multi-link STA successfully competes for the channel of Link 1 and sends PPDU1 containing uplink data. The receiver of the uplink data is the AP. The AP sends PPDU2 containing acknowledgment information after the SIFS time. Of course, PPDU2 can also include other frames. At the same time, the AP starts to compete for the channel on Link 2 at the end of PPDU1 sent by STA A. After seizing the channel, it sends PPDU3 to station A or other stations on Link 2. The end time of this PPDU3 is the same as the method mentioned above and will not be elaborated here.

[0110] In this scenario of the second embodiment, other multi-link stations (except the first multi-link device and the second device) 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) among other multi-link stations can, during the transmission time of the second PPDU sent by the second device, send other message packets to another station (non-AP STA) on the second link through channel competition. The specific implementation method is as follows:

[0111] The 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, when the first PPDU is for downlink transmission, other multi-link stations within this BSS can, after the end time of the first PPDU, perform TDLS message packet transmission by competing for the channel on other links (the second link), but the receiving object of the TDLS message packet cannot be the receiver of the first PPDU, that is, the second device. There are no other restrictions in other cases.

[0112] Second Embodiment: If the first multi-link device is a multi-link station, when the multi-link station first sends a first PPDU on the first link, at this time, other multi-link stations within this BSS can, on other links (the second link), transmit TDLS message packets by competing for the channel. When the TDLS message packet receiving object is 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 being earlier than or equal to. In other cases, there are no restrictions.

[0113] Adopting the solution of the embodiment of the present application, in a scenario where simultaneous multi-link transceiver is not supported, when a multi-link device receives a PPDU sent by a first multi-link device on a first link, the multi-link device can start seizing the channel (including actions such as listening and backoff) on another link at the end of this PPDU so as to send a PPDU, which can not only ensure the fairness of multi-link access, but also reduce the idle rate of multi-links and improve the frequency efficiency.

[0114] It should be noted that the solutions of Embodiment 1 and Embodiment 2 of the present application can be used not only in a scenario where a multi-link device does not support simultaneous transceiver on a first link and on a second link, but also in a scenario where a multi-link device supports simultaneous transceiver on a first link and on a second link.

[0115] Embodiment 3

[0116] For the case of 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 this message packet will leak to other links, even when the channels on other links are idle, the clear channel assessment (CCA) detection result will indicate that the channel is busy. Embodiments of this application propose that the multi-link device can, through calibration, test in advance the power of different power data packets leaked to other links under the condition that multiple links are idle, for example, detecting that the self-interference leakage is X dB. Therefore, for the case of multi-links that do not support simultaneous transmission and reception, when the multi-link device first sends a message packet on one link and performs CCA detection on other links to determine whether the channel on that link is idle or busy, the detection threshold for CCA detection on other links needs to be backed off by (X - C) dB, where C is a fixed safety value specified by the protocol, which can be 0 or other values. This method of backing off the detection threshold can be applied to energy detection and signal detection. For example, when using signal detection, the normal signal detection threshold for the main 20M is -82 dBm, that is, if the energy detected by CCA is greater than or equal to -82 dBm, it indicates that the channel is busy, otherwise it indicates that the channel is idle. For the scenario where the multi-link station sends a data packet on one link, the detection threshold for CCA detection on other links can be (-82 + X1 + -C1) dBm, where C1 is the estimated safety value, which can be agreed upon by the protocol, can be 0, or can be other values, and X1 is the self-interference leakage. When the power detected by CCA is greater than or equal to (-82 + X1 + -C1) dBm, it is determined that the channel is busy; otherwise, it is determined that the channel is idle. For example, when using energy detection, the normal energy detection threshold for the main 20 MHz is -62 dBm, (-62 + X2 - C2), where C2 is the estimated safety value, which can be agreed upon by the protocol, can be 0, or can be other values, and X2 is the self-interference leakage. When the power detected by CCA is greater than or equal to (-62 + X1 + -C1) dBm, it is determined that the channel is busy; otherwise, it is determined that the channel is idle. Optionally, X1 and X2 may be the same or different, and C1 and C2 may also be the same or different.

[0117] By using the detection method of the embodiments of this application, the accuracy of CCA detection can be improved, so that the multi-link device can more accurately determine the idle and busy states of the channel. It should be noted that the method for setting the detection threshold proposed in Embodiment 3 is not limited to being applicable to the solutions of any of the above embodiments, and can also be applied to other scenarios of multi-link communication.

[0118] The method of the embodiments of this application is elaborated in detail above, and the device of the embodiments of this application is provided below.

[0119] Please refer to Figure 9 , Figure 9It is a schematic structural diagram of a multi-link communication device provided by 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 foregoing 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 a possible design, one transceiver module may correspond to one station in the multi-link device and may include a baseband circuit and a radio frequency circuit. In another possible design, one 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 each module in the communication device 900 is only exemplary.

[0120] In a possible design, the multi-link communication device 900 can implement any method and function of the multi-link device in the first embodiment above. For example, the processing module 901 is used 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. The first processing module is used to generate the first PPDU, and the second processing module is used to generate the second PPDU. The first transceiver module 902a is used to send the first PPDU on the first link, for example, to implement step S101. The second transceiver module 902b is used to send the second PPDU on the second link by competing for the channel, where the end time of the second PPDU is not later than the end time of the first PPDU, for example, to implement step S102. Optionally, the first transceiver module 902a is further used to receive the first acknowledgment information on the first link, and the second transceiver module 902b is further used to receive the second acknowledgment information on the second link.

[0121] In another possible design, the multi-link communication device 900 can implement any method and function of the first multi-link device in the second embodiment above. For example, the processing module 901 is used to generate a first PPDU; the first transceiver module 902a is used to send the first PPDU on the first link, for example, to implement step S201. The first transceiver module 902a is further used to receive the second PPDU in response to the first PPDU on the first link, for example, to implement step S203; the second transceiver module 902b is used to receive the third PPDU sent by the third multi-link device on the second link on the second link, where the end time of the third PPDU is not later than the end time of the second PPDU, for example, to implement step S206.

[0122] In yet another possible design, the multi-link communication device 900 may implement any of the methods and functions of the third multi-link device in the second embodiment above. For example, the processing module 901 is used to generate a third PPDU; the first transceiver module 902a is used to obtain or receive a first PPDU on the first link, for example, to implement step S204; the second transceiver module 902b is used to send the third PPDU on the second link, and the end time of the third PPDU is not later than the end time of the second PPDU, for example, to implement step S205.

[0123] In yet another possible design, the multi-link communication device may implement the CCA detection in the third embodiment above. For example, the transceiver module is used to perform CCA detection; the processing module is used to judge the channel idle or busy state according to the detection result of the transceiver module. The processing module is used to judge that the channel on the second link is busy when the power detected by the transceiver module on the channel of the second link is greater than or equal to (-82 + X1 + -C1) dBm; the processing module is used to judge that the channel on the second link is idle when the power detected by the transceiver module on the channel of the second link is less than (-82 + X1 + -C1) dBm.

[0124] See Figure 10 , Figure 10 FIG. is a schematic structural diagram of a multi-link communication device provided by an embodiment of the present application. The multi-link communication device may be used to implement any of the methods and functions of the multi-link communication device in any of the foregoing 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 further includes a memory 1003. In one possible design, a station in the multi-link device includes a separate radio frequency circuit and a baseband circuit, and can independently implement the transceiver functions on the working link; in another possible design, a station in the multi-link device includes a common baseband circuit part and an independent radio frequency circuit part. In this case, the data sent by the station on the working link may be generated by the common baseband circuit, and in this case, the baseband circuit may be included in the processor 1001. The processor 1001 is used to execute instructions to implement the control and management of the multi-link communication device, and also includes the processing of signaling or data, etc. The bus 1002 is used to couple and connect each device so that each device can complete the interaction of data or information. The memory 1003 may include computer programs or instructions, and the processor 1001 may run the instructions to implement the functions in the above method embodiments.

[0125] In a 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 used to generate the first PPDU and the second PPDU. Optionally, the processor can also be a baseband circuit, which is used to generate the first PPDU and the second PPDU. The radio frequency circuit 1004a is used to send the first PPDU on the first link. For example, it is used to implement step S101. The radio frequency circuit 1004b is used to send the second PPDU on the second link through a contention channel, where the end time of the second PPDU is not later than the end time of the first PPDU. For example, it is used to implement step S102. Optionally, the radio frequency circuit 1004a is further used to receive the first acknowledgment information on the first link, and the radio frequency circuit 1004b is further used to receive the second acknowledgment information on the second link.

[0126] In another possible design, the multi-link communication device can implement any of the methods and functions of the first multi-link device in the second embodiment above. For example, the processor 1001 is used to generate the first PPDU; the radio frequency circuit 1004a is used to send the first PPDU on the first link. For example, it is used to implement step S201. The radio frequency circuit 1004a is further used to receive the second PPDU in response to the first PPDU on the first link. For example, it is used to implement step S203; the radio frequency circuit 1004b is used to receive the third PPDU sent by the third multi-link device on the second link on the second link, where the end time of the third PPDU is not later than the end time of the second PPDU. For example, it is used to implement step S206.

[0127] In yet another possible design, the multi-link communication device can implement any of the methods and functions of the third multi-link device in the second embodiment above. For example, the processor 1001 is used to generate the third PPDU; the radio frequency circuit 1004a is used to obtain or receive the first PPDU on the first link. For example, it is used to implement step S204; the radio frequency circuit 1004b is used to send the third PPDU on the second link, and the end time of the third PPDU is not later than the end time of the second PPDU. For example, it is used to implement step S205. Optionally, the processor 1001 can also be used to obtain the transmission duration of the second PPDU according to the transmission duration information carried in the first PPDU and / or the second PPDU, so as to determine the transmission duration or the end time of the third PPDU.

[0128] In yet another possible design, the multi-link communication device can implement the CCA detection in the third embodiment above. For example, the radio frequency circuit is used for CCA detection; the processor 1001 is used to determine the busy or idle 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 of 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 of the second link is less than (-82 + X1 + -C1) dBm.

[0129] See Figure 11 , Figure 1 FIG. is a schematic 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 foregoing 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 foregoing embodiments. The chip system can include a processor, and optionally further includes a memory for storing programs or instructions.

[0130] In a possible design, the processor is used to execute programs or instructions to enable the multi-link communication device to implement any method and function in Embodiment 1. In another possible design, the processor is used to execute programs or instructions to enable the multi-link communication device to implement any method and function in Embodiment 2. In yet another possible design, the processor is used to execute programs or instructions to enable the multi-link communication device to implement any method and function in Embodiment 3.

[0131] It should be noted that the memory can be included in the processor or can also be a storage unit external to the processor and coupled to the processor.

[0132] The embodiment of the present application also provides a processor for coupling with a memory and used to execute any method and function related to the first multi-link device or the third multi-link device in any of the foregoing embodiments.

[0133] The embodiment of the present application also provides a computer program product containing instructions, which when running on a computer enables the computer to execute any method and function related to the first multi-link device or the third multi-link device in any of the foregoing embodiments.

[0134] The embodiment of the present application also provides a device for executing any method and function related to the first multi-link device or the third multi-link device in any of the foregoing embodiments.

[0135] 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 of the second embodiments above.

[0136] 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 processes or functions described in the embodiments of the present application are generated in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center by wire (such as coaxial cable, optical fiber, digital subscriber line (DSL)) or wirelessly (such as infrared, wireless, microwave, etc.). The computer-readable storage medium may be any available medium that can be accessed by a computer or a data storage device such as a server or data center that includes one or more integrated available media. The available medium may be a magnetic medium (such as a floppy disk, hard disk, magnetic tape), an optical medium (such as a DVD), or a semiconductor medium (such as a solid state disk (SSD)), etc.

Claims

1. A multi-link communication method, characterized in that, including: The multi-link device sends a first physical layer protocol data unit (PPDU) on a first link; The multi-link device sends a second PPDU on a second link by competing for a channel, where an end time of the second PPDU is earlier than an end time of the first PPDU.

2. The method according to claim 1, characterized in that, A transmission time of the second PPDU is not earlier than a transmission time of the first PPDU.

3. The method according to claim 1 or 2, characterized in that, The first PPDU includes an uplink / downlink indication for indicating a transmission direction of the first PPDU, and the transmission direction includes uplink or downlink.

4. The method according to claim 1 or 2, characterized in that, The first PPDU includes first TXOP duration information indicating a duration of a first TXOP, the second PPDU includes second TXOP duration information indicating a duration of a second TXOP, and the duration of the first TXOP is the same as the duration of the second TXOP.

5. A multi-link communication method, characterized in that, The method includes: A first multi-link device sends a first physical layer protocol data unit (PPDU) on a first link; After a preset time interval, the first multi-link device receives, on the first link, a second PPDU from a second device in response to the first PPDU; The first multi-link device receives, 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 earlier than an end time of the second PPDU.

6. The method according to claim 5, characterized in that, The third multi-link device is a destination receiver of the first PPDU, or the third multi-link device is not a destination receiver of the first PPDU.

7. The method according to claim 5 or 6, characterized in that, A start time of the third PPDU is not earlier than an end time of the first PPDU.

8. The method according to claim 5 or 6, characterized in that, The first PPDU includes transmission duration information for indicating a transmission duration of the second PPDU; or A physical layer preamble of the second PPDU includes the transmission duration information for indicating a transmission duration of the second PPDU.

9. The method according to claim 5 or 6, characterized in that, The third PPDU includes third TXOP duration information indicating a third TXOP duration, and the third TXOP duration does not exceed a minimum value or an earliest end value of a first TXOP duration indicated by the first TXOP duration information in the first PPDU and a second duration; where the second duration is a transmission duration of the second PPDU, or the transmission duration of the second PPDU + SIFS + a transmission duration of an acknowledgment message in response to the second PPDU.

10. A multi-link communication method, characterized in that, The method includes: A third multi-link device obtains a first PPDU transmitted by a first multi-link device on a first link; On a second link, the third multi-link device sends a third PPDU, where an end time of the third PPDU is earlier than an end time of a second PPDU, and the second PPDU is sent on the first link and in response to the first PPDU.

11. The method according to claim 10, characterized in that, The third multi-link device is a destination receiver of the first PPDU, or the third multi-link device is not a destination receiver of the first PPDU.

12. The method according to claim 10 or 11, characterized in that, A start time of the third PPDU is not earlier than an end time of the first PPDU.

13. The method according to claim 10 or 11, characterized in that, The first PPDU includes transmission duration information for indicating the transmission duration of the second PPDU; or, The physical layer preamble of the second PPDU includes the transmission duration information for indicating the transmission duration of the second PPDU.

14. The method according to claim 10 or 11, characterized in that, 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 indicated by the first TXOP duration information in the first PPDU and a second duration; 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 acknowledgment information in response to the second PPDU.

15. A multi-link communication device, characterized in that, Comprising: A first sending module, configured to send a first physical layer protocol data unit (PPDU) on a first link; A second sending module, configured to send a second PPDU on a second link by competing for a channel, wherein an end time of the second PPDU is earlier than an end time of the first PPDU.

16. The device according to claim 15, characterized in that, A sending time of the second PPDU is not earlier than a sending time of the first PPDU.

17. The device according to claim 15 or 16, characterized in that, The first PPDU includes an uplink / downlink indication for indicating a transmission direction of the first PPDU, and the transmission direction includes uplink or downlink.

18. The device according to claim 15 or 16, characterized in that, The first PPDU includes first TXOP duration information indicating a duration of a first TXOP, the second PPDU includes second TXOP duration information indicating a duration of a second TXOP, and the duration of the first TXOP is the same as the duration of the second TXOP.

19. A first multi-link device, characterized in that, The device includes: A first sending module, configured to send a first physical layer protocol data unit (PPDU) on a first link; A first receiving module, configured to, after a preset time interval, the first multi-link device receive, on the first link, a second PPDU from a second device in response to the first PPDU; A second receiving module, configured to receive, on a second link, a third PPDU sent by a third multi-link device on the second link, and an end time of the third PPDU is earlier than an end time of the second PPDU.

20. The device according to claim 19, characterized in that, The third multi-link device is a destination receiver of the first PPDU, or the third multi-link device is not a destination receiver of the first PPDU.

21. The device according to claim 19 or 20, characterized in that, A start time of the third PPDU is not earlier than an end time of the first PPDU.

22. The device according to claim 19 or 20, characterized in that, The first PPDU includes transmission duration information for indicating the transmission duration of the second PPDU; or, The physical layer preamble of the second PPDU includes the transmission duration information for indicating the transmission duration of the second PPDU.

23. The device according to claim 19 or 20, characterized in that, 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 ending value of the first TXOP duration indicated by the first TXOP duration information in the first PPDU and the second duration; 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 acknowledgment information in response to the second PPDU.

24. A third multi-link device, characterized in that, The device includes: A first sending module, which obtains a first PPDU transmitted by a first multi-link device on a first link; A second sending module, configured to send a third PPDU on a second link, where an end time of the third PPDU is earlier than an end time of a second PPDU, and the second PPDU is sent on the first link and in response to the first PPDU.

25. The device according to claim 24, characterized in that, The third multi-link device is a destination receiving end of the first PPDU, or the third multi-link device is not a destination receiving end of the first PPDU.

26. The device according to claim 24 or 25, characterized in that, A start time of the third PPDU is not earlier than an end time of the first PPDU.

27. The device according to claim 24 or 25, characterized in that, The first PPDU includes transmission duration information for indicating a transmission duration of the second PPDU; or a physical layer preamble of the second PPDU includes the transmission duration information for indicating a transmission duration of the second PPDU.

28. The device according to claim 24 or 25, characterized in that, 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 ending value of the first TXOP duration indicated by the first TXOP duration information in the first PPDU and the second duration; 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 acknowledgment information in response to the second PPDU.

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