Link status indication method in EMLSR mode and related device

Abstract

The present application relates to the field of wireless communication, and is applied to a wireless local area network supporting 802.11be or next generation standards, and in particular to a link status indication method in EMLSR mode. The method includes: when the EMLSR non-AP MLD determines that the status of all or some links of the EMLSR non-AP MLD has changed, the EMLSR non-AP MLD transmits a frame on any available link. The frame carries indication information indicating the available link or the link whose status has changed in the EMLSR non-AP MLD. Alternatively, the frame may carry another indication information indicating that the status of the link has changed. According to an embodiment of the present application, the AP MLD does not transmit a signal to the EMLSR non-AP MLD on the unavailable link of the EMLSR non-AP MLD to reduce resource waste.

Description

[Technical field]

[0001] This application claims priority to Chinese Patent Application No. 202210153355.9, filed with the State Intellectual Property Office of China on February 18, 2022, entitled "METHING AND RELATED DEVICE FOR INDICATING LINK STATUS IN EMLSR MODE", and Chinese Patent Application No. 202210504981.8, filed with the State Intellectual Property Office of China on May 10, 2022, entitled "METHING AND RELATED DEVICE FOR INDICATING LINK STATUS IN EMLSR MODE", both of which are incorporated by reference in their entireties herein.

[0002] The present application relates to the field of wireless communication technologies, and in particular to a link status indication method and related apparatus in enhanced multi-link single radio (EMLSR) mode. [Background technology]

[0003] A continuous technical goal of the development and evolution of wireless local area networks (WLANs) or cellular networks is to continuously improve throughput. The protocols of WLAN systems are mainly discussed by the standards group of the Institute of Electrical and Electronics Engineers (IEEE). Standards such as IEEE 802.11a / b / g / n / ac / ax have continuously improved throughput. The next generation Wi-Fi standard, IEEE 802.11be, is called extremely high throughput (EHT) or Wi-Fi 7. The key technology of this standard is to improve throughput by using multi-link (ML) communication. The core concept of multi-link communication is that WLAN devices supporting the next generation IEEE 802.11 standard, i.e. EHT devices, have multi-band transmission and reception capabilities, thus using a larger bandwidth for data transmission, greatly improving throughput. Multi-band includes, but is not limited to, 2.4 GHz Wi-Fi band, 5 GHz Wi-Fi band, and 6 GHz Wi-Fi band. A band is called a link, and multiple bands are called multiple links. In 802.11be, a WLAN device supporting multi-link communication is called a multi-link device (MLD). Obviously, a multi-link device can perform parallel communication on multiple links (or multiple bands), which results in a significant improvement in transmission rate. A multi-link device (MLD) includes one or more affiliated stations (STAs). An affiliated station is a logical station and may operate on one link. An affiliated station may be an access point (AP) or a non-access point station (non-AP STA).In the 802.11be standard, a multilink device whose associated stations are APs is called an AP MLD, and a multilink device whose associated stations are non-AP STAs is called a non-AP MLD.

[0004] However, since there may be stations (STAs) with limited reception capabilities in some cases, the enhanced multi-link single radio (EMLSR) mode is introduced and is mainly applied to non-AP MLD. In the EMLSR mode, non-AP MLD receives frames on each link in single radio mode, i.e., performs a listening operation on the channel in a 1x1 (one input, one output) manner, and receives initial control frames sent by AP MLD in orthogonal frequency division multiplexing (OFDM) physical layer protocol data unit (PPDU) type and non-high throughput (HT) duplicate PPDU type, and reception of other types of frames is currently not supported. In EMLSR mode, after receiving the initial control frame sent by the AP MLD on the EMLSR link, the non-AP MLD STA temporarily switches the spatial streams / receiving antennas on another link to the EMLSR link to form a 2×2 (2-input and 2-output) antenna configuration to carry out subsequent data transmission. The listening operation in this specification is defined as clear channel assessment (CCA).

[0005] Since the non-AP MLD in EMLSR mode may have multiple (two or more) antennas, each antenna corresponds to a different STA of the non-AP MLD and operates through a different link. For an AP MLD associated with a non-AP MLD in EMLSR mode, the non-AP MLD or the entire STA on some links of the non-AP MLD may be unavailable due to some reasons (including but not limited to the coexistence of different devices or different technologies). Therefore, when the non-AP MLD or the entire STA on some links of the non-AP MLD is unavailable for some reason, normal communication is affected. Summary of the Invention [Means for solving the problem]

[0006] The present application provides a link status indication method and related device in EMLSR mode, so that an AP MLD can timely know the link status change of an EMLSR non-AP MLD associated with the AP MLD, and the AP MLD will not send signals to the EMLSR non-AP MLD on the unavailable link of the EMLSR non-AP MLD, in order to reduce resource waste.

[0007] The present application provides a link status indication method and related device for a non-AP MLD with NSTR capability, so that an AP MLD can timely know the status change of the NSTR link of a non-AP MLD associated with the AP MLD, and the AP MLD will not send a signal to the non-AP MLD on the non-AP MLD's unavailable NSTR link, in order to reduce resource waste.

[0008] In the following, the present application will be described from various aspects. It should be understood that cross-reference may be made to the following implementations and advantageous effects of different aspects.

[0009] In this application, for ease of explanation, "non-AP MLD in EMLSR mode (operating)" is denoted as "EMLSR non-AP MLD". In other words, EMLSR non-AP MLD may indicate that one or more links (stations) of the non-AP MLD enter EMLSR mode. Similarly, "station entering EMLSR mode in EMLSR non-AP MLD" may be denoted as "EMLSR STA".

[0010] In this application, for ease of explanation, "a link in some link pairs having NSTR capability in a non-AP MLD" is referred to as an NSTR link.

[0011] In the following, the link status indication in EMLSR mode is used as an example, and the link status indication in other modes is similar.

[0012] According to a first aspect, the present application provides a link state indication method in an EMLSR mode. The method includes the steps of: when the EMLSR non-AP MLD confirms that all links (or STAs on all links) of the EMLSR non-AP MLD are unavailable for the AP MLD associated with the EMLSR non-AP MLD, the EMLSR non-AP MLD generates a first frame and transmits the first frame on any available link. The first frame may include first indication information indicating that (all links of) the EMLSR non-AP MLD are disabled for the AP MLD. The first frame may be a data frame.

[0013] It should be understood that "disabled", "unavailable", etc. in this application are all relative to the AP MLD. For example, "EMLSR non-AP MLD is disabled" means that the EMLSR non-AP MLD cannot be used for an AP MLD associated with the EMLSR non-AP MLD, or that the AP MLD cannot communicate with the EMLSR non-AP MLD, or that the EMLSR non-AP MLD does not receive or respond to uplink trigger frames for the AP MLD. However, the EMLSR non-AP MLD may communicate with another non-AP MLD or single-link STA. That is, the EMLSR non-AP MLD is still available for another non-AP MLD or single-link STA.

[0014] It should be further appreciated that after the EMLSR non-AP MLD transmits its first frame, or after a period of time after the EMLSR non-AP MLD transmits its first frame, the EMLSR non-AP MLD (all links of the EMLSR non-AP MLD) is unavailable to the AP MLD associated with the EMLSR non-AP MLD.

[0015] When the EMLSR non-AP MLD is temporarily unavailable for some reason, the AP MLD associated with the EMLSR non-AP MLD cannot communicate with the EMLSR non-AP MLD. However, the AP MLD does not know whether the EMLSR non-AP MLD associated with the AP MLD is currently unavailable. Therefore, when the AP MLD wants to communicate with the EMLSR non-AP MLD, the AP MLD sends a signal, such as an initial control frame, to the EMLSR non-AP MLD. In addition, the link resource of the EMLSR non-AP MLD is occupied or the antenna resource is occupied, and the initial control frame sent by the AP MLD cannot be received correctly, and therefore cannot respond to the initial control frame. As a result, the AP MLD cannot receive a response to the initial control frame and may repeatedly send the initial control frame. Every time before sending the initial control frame, the AP MLD will implement channel contention to obtain channel resources for sending the initial control frame, causing resource waste.

[0016] Therefore, in the present application, when the EMLSR non-AP MLD is temporarily unavailable for some reason, the first indication information is carried in the data frame to report that the EMLSR non-AP MLD is unavailable, so that the AP MLD knows the status change of the link to the EMLSR non-AP MLD in a timely manner, and the AP MLD does not send a signal, such as an initial control frame, to the EMLSR non-AP MLD on the unavailable link of the EMLSR non-AP MLD, so as to reduce resource waste.

[0017] Regarding the first aspect, in one possible implementation form, the first frame further includes an uplink multi-user disablement subfield and / or an uplink multi-user data disablement subfield.

[0018] Optionally, both the uplink multi-user disable subfield and the uplink multi-user data disable subfield are set to 1.

[0019] Regarding the first aspect, in one possible implementation form, after the EMLSR non-AP MLD notifies the AP MLD associated with the EMLSR non-AP MLD that the EMLSR non-AP MLD has entered an unavailable state, if the EMLSR non-AP MLD confirms that the link of the EMLSR non-AP MLD has resumed availability, the EMLSR non-AP MLD may transmit a second frame to the AP MLD on the link that has resumed availability. That is, after the EMLSR non-AP MLD transmits the first frame, the method further includes a step of the EMLSR non-AP MLD transmitting a second frame. The second frame may include second indication information indicating that the EMLSR non-AP MLD (link) is enabled, or indicating that the EMLSR non-AP MLD (link) resumes, or indicating that the EMLSR non-AP MLD (link) switches back to listening operation. The second frame may be a data frame.

[0020] Optionally, the second indication information may be carried in an EHT OM control subfield. The second frame may further include an OM control subfield. The OM control subfield includes an uplink multi-user disable subfield and an uplink multi-user data disable subfield. Both the uplink multi-user disable subfield and the uplink multi-user data disable subfield are set to 1.

[0021] Regarding the first aspect, in one possible implementation form, the second indication information indicates that a first link of the EMLSR non-AP MLD is available, and the first link is a link for transmitting the second frame by the EMLSR non-AP MLD.

[0022] Optionally, the second indication information may be carried in an EHT OM control subfield. The second frame may further include an OM control subfield. The OM control subfield includes an uplink multi-user disable subfield and an uplink multi-user data disable subfield. Both the uplink multi-user disable subfield and the uplink multi-user data disable subfield are set to 0. The uplink multi-user disable subfield is set to 0, the uplink multi-user data disable subfield is set to 0, and the second indication information jointly indicates that the first link of the EMLSR non-AP MLD is available.

[0023] In the present application, when the entire EMLSR non-AP MLD ends its unavailability, or when an EMLSR STA on the link of the EMLSR non-AP MLD ends its unavailability and is ready to resume to listening mode, the AP MLD is notified using the second indication information, so that the AP MLD knows the available link of the EMLSR non-AP MLD in a timely manner, and the AP MLD schedules the EMLSR non-AP MLD to perform uplink transmission or transmits downlink data to the EMLSR non-AP MLD.

[0024] Regarding the first aspect, in one possible implementation, the antenna capability configuration of the EMLSR non-AP MLD is asymmetric. That is, each link of the EMLSR non-AP MLD has one antenna. One antenna is a common antenna, and the other antenna is a limited antenna. The link where the common antenna is deployed is called a RX full capability link, and the link where the limited antenna is deployed is called a RX limitation link. Alternatively, there is at least one RX full capability link and at least one RX limitation link in the EMLSR non-AP MLD. When the RX full capability link of the EMLSR non-AP MLD is available, the EMLSR non-AP MLD receives a multi-user request to send (MU-RTS) frame or a buffer status report poll (BSRP) frame. The MU-RTS frame or the BSRP frame carries an indication information indicating whether the MU-RTS frame or the BSRP frame is an initial control frame, or whether the MU-RTS frame or the BSRP frame received by the station is an initial control frame.

[0025] In this application, when the antenna capability configuration of the EMLSR non-AP MLD is asymmetric, the indication information is carried in the MU-RTS frame or the BSRP frame to indicate whether the MU-RTS frame or the BSRP frame is an initial control frame, or whether the MU-RTS frame or the BSRP frame received by the station is an initial control frame. In this way, the EMLSR STA on the receiving full capability link of the EMLSR non-AP MLD can determine whether the received MU-RTS frame or the BSRP frame is an initial control frame to determine the subsequent behavior of the EMLSR STA.

[0026] According to a second aspect, the present application provides a link state indication method in EMLSR mode. The method includes the steps of: an AP MLD receiving a first frame, the first frame including first indication information, the first indication information indicating that (all links of) the EMLSR non-AP MLD are disabled. The AP MLD determines that the EMLSR non-AP MLD is disabled for the AP MLD based on the first indication information in the first frame. The first frame may be a data frame.

[0027] Regarding the second aspect, in one possible implementation, the first indication information may be carried in an EHT OM control subfield. The EHT OM control subfield is an extension of the OM Control subfield in the EHT background. The first frame may further include an OM control subfield, and the OM control subfield includes an uplink multi-user disable subfield and / or an uplink multi-user data disable subfield. It should be understood that if the first frame includes an uplink multi-user disable subfield and / or an uplink multi-user data disable subfield, when reading the first indication information, the AP MLD may ignore the value to which the uplink multi-user disable subfield and / or the uplink multi-user data disable subfield in the first frame is set.

[0028] Optionally, both the uplink multi-user disable subfield and the uplink multi-user data disable subfield are set to 1.

[0029] Regarding the second aspect, in one possible implementation, after the AP MLD receives the first frame, the method further includes the AP MLD receiving a second frame. The second frame includes second indication information. The second indication information indicates that the EMLSR non-AP MLD (link) is available, or indicates that the EMLSR non-AP MLD (link) resumes, or indicates that the EMLSR non-AP MLD (link) switches back to listening operation. The second frame may be a data frame.

[0030] Optionally, the second indication information may be carried in an EHT OM control subfield. The second frame may further include an OM control subfield. The OM control subfield includes an uplink multi-user disable subfield and an uplink multi-user data disable subfield. Both the uplink multi-user disable subfield and the uplink multi-user data disable subfield are set to 1.

[0031] Regarding the second aspect, in one possible implementation form, the second indication information indicates that a first link of the EMLSR non-AP MLD is available, and the first link is a link for transmitting the second frame by the EMLSR non-AP MLD.

[0032] Optionally, the second indication information may be carried in an EHT OM control subfield. The second frame may further include an OM control subfield. The OM control subfield includes an uplink multi-user disable subfield and an uplink multi-user data disable subfield. Both the uplink multi-user disable subfield and the uplink multi-user data disable subfield are set to 0. The uplink multi-user disable subfield is set to 0, the uplink multi-user data disable subfield is set to 0, and the second indication information jointly indicates that the first link of the EMLSR non-AP MLD is available.

[0033] With regard to the second aspect, in one possible implementation, when a receiving full-capability link of the EMLSR non-AP MLD is available, the AP MLD may send an MU-RTS frame or a BSRP frame carrying indication information to the EMLSR non-AP MLD to indicate whether the MU-RTS frame or the BSRP frame is an initial control frame or whether the MU-RTS frame or the BSRP frame received by the station is an initial control frame.

[0034] According to a third aspect, the present application provides a communication device. The communication device may be a non-AP MLD or a chip in the non-AP MLD, for example, a Wi-Fi chip. The communication device includes a processing unit configured to generate a first frame, the first frame including first indication information, the first indication information indicating that the EMLSR non-AP MLD is disabled for the AP MLD, and a transceiver unit configured to transmit the first frame. The first frame is a data frame.

[0035] Regarding the third aspect, in one possible implementation form, the first indication information may be carried in an EHT OM control subfield. The EHT OM control subfield is an extension of the OM Control subfield in the EHT background. The first frame may further include an OM control subfield, where the OM control subfield includes an uplink multi-user disable subfield and / or an uplink multi-user data disable subfield.

[0036] Optionally, both the uplink multi-user disable subfield and the uplink multi-user data disable subfield are set to 1.

[0037] Regarding the third aspect, in one possible implementation, the transceiver unit is further configured to transmit a second frame, the second frame including second indication information, the second indication information indicating that the EMLSR non-AP MLD is available, the second frame being a data frame.

[0038] Optionally, the second frame further includes an uplink multi-user disable subfield and an uplink multi-user data disable subfield, where both the uplink multi-user disable subfield and the uplink multi-user data disable subfield are set to 1.

[0039] Regarding the third aspect, in one possible implementation form, the second indication information indicates that a first link of the EMLSR non-AP MLD is available, and the first link is a link for transmitting the second frame by the EMLSR non-AP MLD.

[0040] Optionally, the second frame further includes an uplink multi-user disable subfield and an uplink multi-user data disable subfield. Both the uplink multi-user disable subfield and the uplink multi-user data disable subfield are set to 0. The uplink multi-user disable subfield is set to 0, the uplink multi-user data disable subfield is set to 0, and the second indication information jointly indicates that the first link of the EMLSR non-AP MLD is available.

[0041] Regarding the third aspect, in one possible implementation, the transceiver unit is further configured to receive an MU-RTS or BSRP frame when a EMLSR non-AP MLD receiving full-capability link is available, The MU-RTS or BSRP frame carries an indication information indicating whether the MU-RTS or BSRP frame is an initial control frame or whether the MU-RTS or BSRP frame received by the station is an initial control frame.

[0042] According to a fourth aspect, the present application provides a communication device. The communication device may be an AP MLD or a chip in the AP MLD, for example a Wi-Fi chip. The communication device includes: a transceiver unit configured to receive a first frame, the first frame including first indication information, the first indication information indicating that EMLSR non-AP MLD is disabled for the AP MLD; and a processing unit configured to determine that EMLSR non-AP MLD is disabled based on the first indication information in the first frame.

[0043] Regarding the fourth aspect, in one possible implementation form, the first indication information may be carried in an EHT OM control subfield. The EHT OM control subfield is an extension of the OM Control subfield in the EHT background. The first frame may further include an OM control subfield, where the OM control subfield includes an uplink multi-user disable subfield and / or an uplink multi-user data disable subfield.

[0044] Optionally, both the uplink multi-user disable subfield and the uplink multi-user data disable subfield are set to 1.

[0045] Regarding the fourth aspect, in one possible implementation, the transceiver unit is further configured to receive a second frame, the second frame including second indication information, the second indication information indicating that the EMLSR non-AP MLD (link) is available, the second frame may be a data frame.

[0046] Optionally, the second frame further includes an uplink multi-user disable subfield and an uplink multi-user data disable subfield, where both the uplink multi-user disable subfield and the uplink multi-user data disable subfield are set to 1.

[0047] Regarding the fourth aspect, in one possible implementation form, the second indication information indicates that a first link of the EMLSR non-AP MLD is available, and the first link is a link for transmitting the second frame by the EMLSR non-AP MLD.

[0048] Optionally, the second frame further includes an uplink multi-user disable subfield and an uplink multi-user data disable subfield. Both the uplink multi-user disable subfield and the uplink multi-user data disable subfield are set to 0. The uplink multi-user disable subfield is set to 0, the uplink multi-user data disable subfield is set to 0, and the second indication information jointly indicates that the first link of the EMLSR non-AP MLD is available.

[0049] Regarding the fourth aspect, in one possible implementation, the transceiver unit is further configured to transmit an MU-RTS or BSRP frame when a EMLSR non-AP MLD receiving full-capability link is available, the MU-RTS or BSRP frame carrying an indication information indicating whether the MU-RTS or BSRP frame is an initial control frame or whether the MU-RTS or BSRP frame received by the station is an initial control frame.

[0050] According to a fifth aspect, the present application provides a link status indication method in an EMLSR mode. The method includes the steps of: when the EMLSR non-AP MLD determines that the status of all or some of the links of the EMLSR non-AP MLD has changed, for example, when at least one link (a station on) of the EMLSR non-AP MLD is unavailable or resumes from unavailable mode to listening mode for an AP MLD associated with the EMLSR non-AP MLD, the EMLSR non-AP MLD generates a third frame and transmits the third frame on any available link. The third frame includes fourth indication information indicating the available link or the link whose status has changed in the EMLSR non-AP MLD.

[0051] In the present application, when the EMLSR non-AP MLD or an EMLSR STA on the link of the EMLSR non-AP MLD is temporarily unavailable for some reason, the changed or available link is actively reported, so that the AP MLD knows the available or changed link of the EMLSR non-AP MLD associated with the AP MLD in a timely manner, and the AP MLD does not send a signal, such as an initial control frame, to the EMLSR non-AP MLD on the unavailable link of the EMLSR non-AP MLD in order to reduce resource waste.

[0052] Regarding the fifth aspect, in one possible implementation, the antenna capability configuration of the EMLSR non-AP MLD is asymmetric. That is, each link of the EMLSR non-AP MLD has one antenna. One antenna is a common antenna, and the other antenna is a limited antenna. Alternatively, the EMLSR non-AP MLD has at least one receiving full capability link and at least one receiving limited link. When the receiving full capability link of the EMLSR non-AP MLD is available, the EMLSR non-AP MLD receives the MU-RTS frame or the BSRP frame. The MU-RTS frame or the BSRP frame carries an indication information indicating whether the MU-RTS frame or the BSRP frame is an initial control frame, or whether the MU-RTS frame or the BSRP frame received by the station is an initial control frame.

[0053] According to a sixth aspect, the present application provides a link status indication method in an EMLSR mode. The method includes a step of an AP MLD receiving a third frame. The third frame includes fourth indication information, and the fourth indication information indicates an available link or a link whose status has changed in the EMLSR non-AP MLD. The AP MLD determines an available link of the EMLSR non-AP MLD based on the fourth indication information in the third frame.

[0054] With regard to the sixth aspect, in one possible implementation, when a receiving full-capability link of the EMLSR non-AP MLD is available, the AP MLD may send an MU-RTS frame or a BSRP frame carrying indication information to the EMLSR non-AP MLD to indicate whether the MU-RTS frame or the BSRP frame is an initial control frame or whether the MU-RTS frame or the BSRP frame received by the station is an initial control frame.

[0055] According to a seventh aspect, the present application provides a communication device. The communication device may be a non-AP MLD or a chip in the non-AP MLD, for example, a Wi-Fi chip. The communication device includes a processing unit configured to generate a third frame, the third frame including fourth indication information, the fourth indication information indicating an available link or a link whose state is changing in the EMLSR non-AP MLD, and a transceiver unit configured to transmit the third frame.

[0056] Regarding the seventh aspect, in one possible implementation, the transceiver unit is further configured to receive an MU-RTS or BSRP frame when a EMLSR non-AP MLD receiving full-capability link is available. The MU-RTS or BSRP frame carries an indication information indicating whether the MU-RTS or BSRP frame is an initial control frame or whether the MU-RTS or BSRP frame received by the station is an initial control frame.

[0057] According to an eighth aspect, the present application provides a communication device. The communication device may be an AP MLD or a chip in the AP MLD, for example a Wi-Fi chip. The communication device includes: a transceiver unit configured to receive a third frame, the third frame including fourth indication information, the fourth indication information indicating an available link or a link whose state is changing in the EMLSR non-AP MLD; and a processing unit configured to determine an available link of the EMLSR non-AP MLD based on the fourth indication information in the third frame.

[0058] Regarding the eighth aspect, in one possible implementation, the transceiver unit is further configured to transmit an MU-RTS or BSRP frame when a EMLSR non-AP MLD receiving full-capability link is available. The MU-RTS or BSRP frame carries an indication information indicating whether the MU-RTS or BSRP frame is an initial control frame or whether the MU-RTS or BSRP frame received by the station is an initial control frame.

[0059] In one possible implementation form of the fifth to eighth aspects, the third frame further includes third indication information, and the third indication information indicates that a state of a link of the non-AP MLD is changed. The non-AP MLD is a non-AP MLD that supports an EMLSR mode.

[0060] In any one possible implementation form of the fifth to eighth aspects, the change in the state of the non-AP MLD link includes, but is not limited to, the EMLSR link being disabled and the EMLSR non-AP MLD unavailable link being changed to an available EMLSR link.

[0061] In one possible implementation form of the fifth to eighth aspects, when the state change of the link of the non-AP MLD is that the EMLSR link is disabled, the third indication information specifically indicates that the EMLSR link is disabled, or indicates that one or more EMLSR links are no longer elements of the EMLSR link and are not used by the non-AP MLD for the EMLSR mode. Correspondingly, the fourth indication information indicates an available link of the EMLSR non-AP MLD or a disabled EMLSR link of the EMLSR non-AP MLD.

[0062] In this application, when the EMLSR non-AP MLD or an EMLSR STA on the link of the EMLSR non-AP MLD is temporarily unavailable for some reason, the EMLSR non-AP MLD reports the state change of the link of the EMLSR non-AP MLD and the changed link to the AP MLD. In this way, the AP MLD knows the available link and / or unavailable link of the EMLSR non-AP MLD in a timely manner, and the AP MLD does not send a signal, such as an initial control frame, to the EMLSR non-AP MLD on the unavailable link of the EMLSR non-AP MLD to reduce resource waste.

[0063] In any one possible implementation form of the fifth to eighth aspects, when the state change of the link of the non-AP MLD is that the unavailable link of the EMLSR non-AP MLD is changing to an available EMLSR link, the third indication information specifically indicates that there is an unavailable link changing (or resuming) to an available EMLSR link in the EMLSR non-AP MLD, or indicates that there is an unavailable link returning to listening operation in the EMLSR non-AP MLD, or indicates that one or more EMLSR links are used by the non-AP MLD for the EMLSR mode and are changing to elements of the EMLSR link or returning to listening operation. Correspondingly, the fourth indication information indicates an available link of the EMLSR non-AP MLD, or an EMLSR link changing from unavailable to available in the EMLSR non-AP MLD.

[0064] In the present application, when the EMLSR non-AP MLD ends its unavailability, or an EMLSR STA on the link of the EMLSR non-AP MLD ends its unavailability and is ready to resume to listening mode, the EMLSR non-AP MLD reports the state change of the link of the EMLSR non-AP MLD and the changed link to the AP MLD, so that the AP MLD knows the available link of the EMLSR non-AP MLD in a timely manner, and the AP MLD schedules the EMLSR non-AP MLD to perform uplink transmission or send downlink data to the EMLSR non-AP MLD.

[0065] In one possible implementation form of the fifth to eighth aspects, the third indication information is represented by two subfields. One subfield indicates that the EMLSR link is disabled, and the other subfield indicates that the available EMLSR link in the EMLSR non-AP MLD has a changed unavailable link. In other words, the third indication information specifically indicates that the EMLSR link is disabled, and that the available EMLSR link in the EMLSR non-AP MLD does not have a changed unavailable link. Alternatively, the third indication information specifically indicates that the EMLSR link is not disabled, and that the available EMLSR link in the EMLSR non-AP MLD has a changed unavailable link.

[0066] In a possible implementation form of any one of the fifth to eighth aspects, the third instruction information and the fourth instruction information may be placed in an AP assistance request (AAR) control subfield of a high throughput (HT) control field of the third frame.

[0067] In the present application, the existing AAR control subfield carries the third indication information and the fourth indication information, and there is no need to design new frame formats and procedures, so that signaling overhead can be reduced.

[0068] In a possible implementation form of any one of the fifth to eighth aspects, the third indication information and the fourth indication information may be placed in an aggregated-control (A-control) subfield of the third frame.

[0069] In this application, the new A-control subfield is designed to carry the third indication information and the fourth indication information. The meaning of the A-control subfield is clear, and the conventional station will not misread the A-control subfield (because the conventional station does not understand the newly designed A-control subfield).

[0070] In one possible implementation form of the fifth to eighth aspects, the third frame is an EML operating mode notification (OMN) frame. The third indication information and the fourth indication information can be placed in an EML control field of the third frame, and an EMLSR mode subfield included in the EML control field is set to 1.

[0071] Optionally, the EML control field may further include one or more of the following information: disable start time, available start time, disable end time, disable duration, and transmitting / receiving capability of the available link of the EMLSR non-AP MLD.

[0072] In this application, the EML control field of the EML OMN frame (i.e., the third frame) carries the third indication information and the fourth indication information. Because the EML control field is extensible, some optional information may be further carried. The implementation of the EML OMN frame is more flexible and more information can be carried.

[0073] In one possible implementation form of the fifth to eighth aspects, the fourth indication is a bitmap, and one bit of the fourth indication corresponds to one link. When a bit in the fourth indication is set to a first value, it indicates that the link corresponding to the bit is an available link or a link whose status is changing. When a bit in the fourth indication is set to a second value, it indicates that the link corresponding to the bit is an unavailable link or a link whose status is not changing. The first value is 1 and the second value is 0, or the first value is 0 and the second value is 1.

[0074] In the present application, by using a bitmap, not only available links or links whose status has changed in the EMLSR non-AP MLD can be indicated, but also unavailable links or links whose status has not changed in the EMLSR non-AP MLD can be indicated. That is, in the present application, the status of each link of the EMLSR non-AP MLD can be indicated by using a bitmap, i.e., available or unavailable, so that the AP MLD can determine the available links of the EMLSR non-AP MLD.

[0075] According to a ninth aspect, the present application provides a link state indication method in EMLSR mode. The method includes a step in which the EMLSR non-AP MLD generates a first EML OMN frame and transmits the first EML OMN frame to the AP MLD after the EMLSR non-AP MLD and the associated AP MLD enter the EMLSR mode by exchanging EML OMN frames. The first EML OMN frame may include an EMLSR mode subfield and an EMLSR link bitmap, the EMLSR mode subfield is set to 1, and the first EML OMN frame is used to notify the updated EMLSR link. It is understood that the meaning of the EMLSR link bitmap is referred to the description of the existing standard. Details are not described in this specification. It is further understood that the frame format of the first EML OMN frame is referred to the description of the EML OMN frame of the existing standard. Details are not described in this specification. In other words, in the present application, the function of the EML OMN frame is added, and the frame format of the EML OMN frame is not changed.

[0076] In this application, no new field (or subfield) needs to be added to indicate the link status change of the EMLSR non-AP MLD, but the function and specific rules of the EML OMN frame are added to notify the link status change. In this way, the AP MLD can timely know the currently available links of the EMLSR non-AP MLD associated with the AP MLD, and the AP MLD will not send signals, such as initial control frames, to the EMLSR non-AP MLD on the unavailable links of the EMLSR non-AP MLD to reduce resource waste.

[0077] Regarding the ninth aspect, in one possible implementation, the antenna capability configuration of the EMLSR non-AP MLD is asymmetric. That is, each link of the EMLSR non-AP MLD has one antenna. One antenna is a common antenna, and the other antenna is a limited antenna. Alternatively, the EMLSR non-AP MLD has at least one receiving full capability link and at least one receiving limited link. When the receiving full capability link of the EMLSR non-AP MLD is available, the EMLSR non-AP MLD receives the MU-RTS frame or the BSRP frame. The MU-RTS frame or the BSRP frame carries an indication information indicating whether the MU-RTS frame or the BSRP frame is an initial control frame, or whether the MU-RTS frame or the BSRP frame received by the station is an initial control frame.

[0078] According to a tenth aspect, the present application provides a link state indication method in EMLSR mode. The method includes a step in which the AP MLD receives a first EML OMN frame after the EMLSR non-AP MLD and the associated AP MLD enter the EMLSR mode by exchanging EML OMN frames. The first EML OMN frame includes an EMLSR mode subfield and an EMLSR link bitmap, the EMLSR mode subfield is set to 1, and the first EML OMN frame is used to notify the updated EMLSR link. Then, the AP MLD determines an available link of the EMLSR non-AP MLD based on the first EML OMN frame.

[0079] With regard to the tenth aspect, in one possible implementation, when a receiving full-capability link of the EMLSR non-AP MLD is available, the AP MLD may send an MU-RTS frame or a BSRP frame carrying indication information to the EMLSR non-AP MLD to indicate whether the MU-RTS frame or the BSRP frame is an initial control frame or whether the MU-RTS frame or the BSRP frame received by the station is an initial control frame.

[0080] According to an eleventh aspect, the present application provides a communication device. The communication device may be a non-AP MLD or a chip in the non-AP MLD, for example, a Wi-Fi chip. The communication device includes: a processing unit configured to generate a first EML OMN frame after an EMLSR non-AP MLD and an associated AP MLD enter an EMLSR mode by exchanging EML OMN frames, the first EML OMN frame includes an EMLSR mode subfield and an EMLSR link bitmap, the EMLSR mode subfield is set to 1, and the first EML OMN frame is used to notify an updated EMLSR link; and a transceiver unit configured to transmit the first EML OMN frame to the AP MLD.

[0081] Regarding the eleventh aspect, in one possible implementation, the transceiver unit is further configured to receive an MU-RTS or BSRP frame when a EMLSR non-AP MLD receiving full-capability link is available. The MU-RTS or BSRP frame carries an indication information indicating whether the MU-RTS or BSRP frame is an initial control frame or whether the MU-RTS or BSRP frame received by the station is an initial control frame.

[0082] According to a twelfth aspect, the present application provides a communication device. The communication device may be an AP MLD or a chip in the AP MLD, for example, a Wi-Fi chip. The communication device includes: a transceiver unit configured to receive a first EML OMN frame after an EMLSR non-AP MLD and an associated AP MLD enter an EMLSR mode by exchanging EML OMN frames, the first EML OMN frame includes an EMLSR mode subfield and an EMLSR link bitmap, the EMLSR mode subfield is set to 1, and the first EML OMN frame is used to notify an updated EMLSR link; and a processing unit configured to determine an available link of the EMLSR non-AP MLD based on the first EML OMN frame.

[0083] With respect to the twelfth aspect, in one possible implementation, the transceiver unit is further configured to transmit an MU-RTS or BSRP frame when a EMLSR non-AP MLD receiving full-capability link is available. The MU-RTS or BSRP frame carries an indication information indicating whether the MU-RTS or BSRP frame is an initial control frame or whether the MU-RTS or BSRP frame received by the station is an initial control frame.

[0084] In a possible implementation form of any one of the ninth to twelfth aspects, the first EML OMN frame further includes one or more of the following information: a start time of an EMLSR link update, and information on the transmission and reception capabilities of the available links of the EMLSR non-AP MLD.

[0085] According to a thirteenth aspect, the present application provides a frame type indication method in an EMLSR mode. The method includes: an EMLSR non-AP MLD has at least one receiving full-capability link and at least one receiving restricted link. The EMLSR non-AP MLD receives an MU-RTS frame or a BSRP frame, the MU-RTS frame or the BSRP frame includes indication information, and the indication information indicates whether the MU-RTS frame or the BSRP frame is an initial control frame. The EMLSR non-AP MLD determines whether the received MU-RTS frame or the BSRP frame is an initial control frame.

[0086] It should be understood that EMLSR non-AP MLD may have links with asymmetric antenna capability configurations. That is, each link has one antenna, where the antenna has stronger receiving capability and can receive all types of PPDUs, and another antenna has weaker receiving capability and can only receive some types of PPDUs. Since the AP may normally communicate with the EMLSR STA with stronger antenna receiving capability and does not need to use the antenna on the other link, the AP may not need to send an initial control frame before sending downlink data to the EMLSR STA with stronger antenna receiving capability. Therefore, when the EMLSR STA receives a MU-RTS frame or a BSRP frame, the EMLSR STA cannot determine whether the received frame is an initial control frame. That is, EMLSR non-AP MLD cannot determine whether the antenna / spatial stream on the other link needs to be temporarily switched to the link on which the EMLSR STA operates.

[0087] Therefore, in the present application, when the antenna capability configuration of the EMLSR non-AP MLD is asymmetric, indication information is added to the MU-RTS frame or BSRP frame to indicate whether the MU-RTS frame or BSRP frame is an initial control frame, so that the EMLSR STA on the receiving full capability link of the EMLSR non-AP MLD can determine whether the received MU-RTS frame or BSRP frame is an initial control frame, and determine the behavior of the EMLSR STA after the EMLSR STA receives the MU-RTS frame or BSRP frame.

[0088] According to a fourteenth aspect, the present application provides a frame type indication method in an EMLSR mode, the method includes: an AP MLD generating and sending an MU-RTS frame or a BSRP frame, the MU-RTS frame or the BSRP frame including indication information, the indication information indicating whether the MU-RTS frame or the BSRP frame is an initial control frame.

[0089] Optionally, the AP MLD may send an MU-RTS frame or a BSRP frame on a full-capability receiving link, or may send an MU-RTS frame or a BSRP frame on a restricted receiving link. Since the EMLSR STA on the restricted receiving link can only receive an initial control frame, the indication information in the MU-RTS frame or the BSRP frame sent on the restricted receiving link indicates that the MU-RTS frame or the BSRP frame is an initial control frame.

[0090] According to a fifteenth aspect, the present application provides a communication device. The communication device may be a non-AP MLD or a chip in the non-AP MLD, for example a Wi-Fi chip. The communication device includes a transceiver unit configured to receive a MU-RTS frame or a BSRP frame, the MU-RTS frame or the BSRP frame including indication information, the indication information indicating whether the MU-RTS frame or the BSRP frame is an initial control frame, and a processing unit configured to determine whether the received MU-RTS frame or the BSRP frame is an initial control frame.

[0091] According to a sixteenth aspect, the present application provides a communication device. The communication device may be an AP MLD or a chip in the AP MLD, for example a Wi-Fi chip. The communication device includes: a processing unit configured to generate a MU-RTS frame or a BSRP frame, the MU-RTS frame or the BSRP frame including indication information, the indication information indicating whether the MU-RTS frame or the BSRP frame is an initial control frame; and a transceiver unit configured to transmit the MU-RTS frame or the BSRP frame.

[0092] In a possible implementation form of any one of the thirteenth to sixteenth aspects, the indication information is placed in a common information field of the MU-RTS frame or the BSRP frame.

[0093] In this application, to solve the problem that a STA on a receiving full-capability link cannot determine whether a received MU-RTS frame or BSRP frame is an initial control frame of an EMLSR mode with an asymmetric antenna configuration, indication information is carried in a common information field.

[0094] In a possible implementation form of any one of the thirteenth to sixteenth aspects, in a first user information field of the indication information control frame, the first user information field includes an association identifier 12 subfield, and the indication information specifically indicates whether the MU-RTS frame or BSRP frame received by the station indicated by the association identifier 12 subfield is an initial control frame.

[0095] Optionally, the control frame includes one or more user information fields, and a first user information field is a user information field corresponding to an EMLSR station in the one or more user information fields. The EMLSR station is a station that enters an EMLSR mode in the EMLSR non-AP MLD.

[0096] In this application, to solve the problem that EMLSR STA on EMLSR non-AP MLD receiving full-capability link cannot determine whether the received MU-RTS frame or BSRP frame is an initial control frame, indication information is carried in the user information field. Different information can be indicated for different stations, and this implementation is more flexible. For example, indication information is carried in the user information field, so that the same MU-RTS frame or BSRP frame is the initial control frame of some EMLSR STAs and the common control frame of other EMLSR STAs.

[0097] According to a seventeenth aspect, the present application provides a communication device. The communication device is specifically a non-AP MLD, and includes a processor and a transceiver. The transceiver is configured to receive and transmit frames, and the processor is configured to execute program instructions, so that the communication device executes the method provided in the embodiment of the present application. Optionally, the communication device further includes a memory. The memory is configured to store a computer program, and the computer program includes the program instructions.

[0098] In one design, the processor is configured to generate a first frame, the first frame including first indication information, the first indication information indicating that EMLSR non-AP MLD is disabled for AP MLD, and the transceiver is configured to transmit the first frame.

[0099] In one design, the processor is configured to generate a third frame, the third frame including fourth indication information, the fourth indication information indicating an available link or a link whose status has changed in the EMLSR non-AP MLD. The transceiver is configured to transmit the third frame. Optionally, the third frame further includes third indication information. The third indication information indicates that a link status of the non-AP MLD has changed, the non-AP MLD being a non-AP MLD that supports the EMLSR mode.

[0100] In one design, after the EMLSR non-AP MLD and the associated AP MLD enter the EMLSR mode by exchanging EML OMN frames, the processor is configured to generate a first EML OMN frame, the first EML OMN frame includes an EMLSR mode subfield and an EMLSR link bitmap, the EMLSR mode subfield is set to 1, and the first EML OMN frame is used to notify the updated EMLSR link. The transceiver is configured to transmit the first EML OMN frame to the AP MLD.

[0101] In one design, the transceiver is configured to receive a control frame, the control frame including indication information, the indication information indicating whether the control frame is an initial control frame, and the EMLSR non-AP MLD has at least one receive full capability link and at least one receive restricted link. The processor is configured to determine whether the received control frame is an initial control frame.

[0102] According to an eighteenth aspect, the present application provides a communication device. The communication device is specifically an AP MLD, and includes a processor and a transceiver. The transceiver is configured to receive and transmit frames, and the processor is configured to execute program instructions, so that the communication device executes the method provided in the embodiment of the present application. Optionally, the communication device further includes a memory. The memory is configured to store a computer program, and the computer program includes the program instructions.

[0103] In one design, the transceiver is configured to receive a first frame, the first frame including first indication information, the first indication information indicating that the EMLSR non-AP MLD is disabled for the AP MLD, and the processor is configured to determine, based on the first indication information in the first frame, that the EMLSR non-AP MLD is disabled.

[0104] In one design, the transceiver is configured to receive a third frame, the third frame including fourth indication information, the fourth indication information indicating an available link or a link whose status has changed in the EMLSR non-AP MLD. The processor is configured to determine an available link of the EMLSR non-AP MLD based on the fourth indication information in the third frame. Optionally, the third frame further includes third indication information, the third indication information indicating a link whose status has changed in the non-AP MLD, the non-AP MLD being a non-AP MLD that supports the EMLSR mode.

[0105] In one design, after the EMLSR non-AP MLD and the associated AP MLD enter the EMLSR mode by exchanging EML OMN frames, the transceiver is configured to receive a first EML OMN frame, the first EML OMN frame including an EMLSR mode subfield and an EMLSR link bitmap, the EMLSR mode subfield is set to 1, and the first EML OMN frame is used to advertise an updated EMLSR link. The processor is configured to determine an available link for the EMLSR non-AP MLD based on the first EML OMN frame.

[0106] In one design, the processor is configured to generate a control frame, the control frame including a first user information field, the control frame including indication information, the indication information indicating whether the control frame is an initial control frame, and the transceiver is configured to transmit the control frame.

[0107] According to a nineteenth aspect, the present application provides a communication device. The communication device is implemented in a chip product form, and includes an input / output interface and a processing circuit. The communication device is a chip in a non-AP MLD.

[0108] In one design, the processing circuit is configured to generate a first frame, the first frame including first instruction information, the first instruction information indicating that EMLSR non-AP MLD is disabled for AP MLD, and the input / output interface is configured to output the first frame and transmit the first frame via the antenna after the first frame is processed by the radio frequency circuit.

[0109] In one design, the processing circuitry is configured to generate a third frame. The third frame includes fourth indication information, the fourth indication information indicating an available link or a link whose status has changed within the EMLSR non-AP MLD. The input / output interface outputs the third frame and transmits the third frame via the antenna after the third frame is processed by the radio frequency circuitry. Optionally, the third frame further includes third indication information. The third indication information indicates that a link status of the non-AP MLD has changed, the non-AP MLD being a non-AP MLD that supports the EMLSR mode.

[0110] In one design, after the EMLSR non-AP MLD and the associated AP MLD enter the EMLSR mode by exchanging EML OMN frames, the processing circuitry is configured to generate a first EML OMN frame. The first EML OMN frame includes an EMLSR mode subfield and an EMLSR link bitmap, where the EMLSR mode subfield is set to 1 and the first EML OMN frame is used to signal the updated EMLSR link. The input / output interface outputs the first EML OMN frame and transmits the first EML OMN frame via the antenna after the first EML OMN frame is processed by the radio frequency circuitry.

[0111] In one design, the input / output interface is configured to input a control frame received via the antenna and the radio frequency circuit. The control frame includes indication information, the indication information indicating whether the control frame is an initial control frame, and the EMLSR non-AP MLD has at least one receiving full-capability link and at least one receiving restricted link. The processing circuit is configured to determine whether the received control frame is an initial control frame.

[0112] According to a twentieth aspect, the present application provides a communication device. The communication device is implemented in a chip product form, and includes an input / output interface and a processing circuit. The communication device is a chip in an AP MLD.

[0113] In one design, the input / output interface is configured to input a first frame received via the antenna and the radio frequency circuit, the first frame including first indication information, the first indication information indicating that the EMLSR non-AP MLD is disabled for the AP MLD, and the processing circuit is configured to determine that the EMLSR non-AP MLD is disabled based on the first indication information in the first frame.

[0114] In one design, the input / output interface is configured to input a third frame received via the antenna and the radio frequency circuit. The third frame includes fourth indication information, the fourth indication information indicating an available link or a link whose status has changed in the EMLSR non-AP MLD. The processing circuit is configured to determine an available link of the EMLSR non-AP MLD based on the fourth indication information in the third frame. Optionally, the third frame further includes third indication information. The third indication information indicates that a link status of the non-AP MLD has changed, the non-AP MLD being a non-AP MLD that supports the EMLSR mode.

[0115] In one design, after the EMLSR non-AP MLD and the associated AP MLD enter the EMLSR mode by exchanging EML OMN frames, the input / output interface is configured to input a first EML OMN frame received via the antenna and the radio frequency circuit, the first EML OMN frame includes an EMLSR mode subfield and an EMLSR link bitmap, the EMLSR mode subfield is set to 1, and the first EML OMN frame is used to notify the updated EMLSR link, and the processing circuit is configured to determine an available link of the EMLSR non-AP MLD based on the first EML OMN frame.

[0116] In one design, the processing circuitry is configured to generate a control frame, the control frame including indication information, the indication information indicating whether the control frame is an initial control frame, and the input / output interface is configured to output the control frame and transmit the control frame via the antenna after the control frame is processed by the radio frequency circuitry.

[0117] According to a twenty-first aspect, the present application provides a computer-readable storage medium. The computer-readable storage medium stores program instructions. When the program instructions are executed in a computer, the computer is enabled to perform a link state indication method in an EMLSR mode according to the first aspect, the second aspect, the fifth aspect, the sixth aspect, the ninth aspect, or the tenth aspect.

[0118] According to a twenty-second aspect, the present application provides a computer-readable storage medium. The computer-readable storage medium stores program instructions. When the program instructions are executed in a computer, the computer is enabled to perform the frame type indication method in EMLSR mode according to the thirteenth or fourteenth aspect.

[0119] According to a twenty-third aspect, the present application provides a computer program product including program instructions, which, when executed on a computer, cause the computer to perform a link state indication method in an EMLSR mode according to the first aspect, the second aspect, the fifth aspect, the sixth aspect, the ninth aspect, or the tenth aspect.

[0120] According to a twenty-fourth aspect, the present application provides a computer program product comprising program instructions, which when executed in a computer, enable the computer to perform the frame type indication method in EMLSR mode according to the thirteenth or fourteenth aspect.

[0121] In this embodiment of the present application, the AP MLD can timely know the link status change of the EMLSR non-AP MLD associated with the AP MLD, so as to reduce resource waste, and as a result, the AP MLD does not send a signal to the EMLSR non-AP MLD on the unavailable link of the EMLSR non-AP MLD. In addition, the problem that the STA on the receiving full-capability link cannot determine whether the received MU-RTS frame or BSRP frame is an initial control frame in the EMLSR mode with asymmetric antenna configuration can be solved.

[0122] According to a twenty-fifth aspect, the present application provides a link status indication method, specifically a link status indication method in an NSTR link pair, including but not limited to the following steps:

[0123] The non-AP MLD generates a third frame, the third frame including a fourth indication, the fourth indication indicating an available link or a link whose status is changing within the non-AP MLD.

[0124] The non-AP MLD sends the third frame.

[0125] According to a twenty-sixth aspect, the present application provides a link status indication method, specifically a link status indication method in an NSTR link pair, including but not limited to the following steps:

[0126] The AP MLD receives a third frame, the third frame including a fourth indication, the fourth indication indicating an available link or a link whose status is changing within the non-AP MLD.

[0127] Optionally, when the third frame further includes third indication information, the third indication information indicates whether the state of the link of non-AP MLD changes.Specifically, for the implementation form of the third indication information and the fourth indication information, please refer to the above description.Details are not described again in this specification.

[0128] The AP MLD determines available links for the non-AP MLD based on the fourth indication information in the third frame.

[0129] Optionally, after receiving the third frame, the AP MLD associated with the non-AP MLD determines an available link for the non-AP MLD based on the third indication information and the fourth indication information carried in the third frame.

[0130] According to a twenty-seventh aspect, the present application provides a communication device, the communication device being configured to perform the link state indication method according to the twenty-fifth or twenty-sixth aspect.

[0131] According to a twenty-eighth aspect, the present application provides a computer-readable storage medium. The computer-readable storage medium stores program instructions. When the program instructions are executed in a computer, the computer is enabled to perform the link state indication method according to the twenty-fifth or twenty-sixth aspect.

[0132] According to a twenty-ninth aspect, the present application provides a computer program product comprising program instructions, which when executed in a computer enable the computer to perform a link state indication method according to the twenty-fifth or twenty-sixth aspect.

[0133] In order to describe the technical solutions in the embodiments of the present application more clearly, the following will briefly describe the accompanying drawings used to describe the embodiments. [Brief description of the drawings]

[0134] [Figure 1] FIG. 1 is a schematic diagram of the architecture of a wireless communication system according to an embodiment of the present application. [Figure 2a] FIG. 2 is a schematic diagram of a structure of a multi-link device according to an embodiment of the present application; [Figure 2b] FIG. 2 is a schematic diagram of another structure of a multi-link device according to an embodiment of the present application. [Diagram 3] FIG. 2 is a schematic diagram of multi-link communication according to an embodiment of the present application; [Figure 4] 1 is a schematic diagram of communication between non-AP MLD and AP MLD in EMLSR mode. [Diagram 5] 1 is a first schematic flowchart of a link state indication method in EMLSR mode according to an embodiment of the present application; [Figure 6] FIG. 2 is a schematic diagram of a frame format of an OM control subfield according to an embodiment of the present application. [Figure 7a] 1 is a schematic diagram of a frame format of an OM Control subfield and an EHT OM control subfield in an HT Control field according to one embodiment of the present application. [Figure 7b] 1 is a schematic diagram of another frame format of an OM Control subfield and an EHT OM control subfield in an HT Control field according to an embodiment of the present application. [Figure 8]2 is a second schematic flowchart of a link state indication method in EMLSR mode according to an embodiment of the present application; [Figure 9a] FIG. 1 is a schematic diagram of a frame format of an AAR control subfield according to an embodiment of the present application. [Figure 9b] A schematic diagram of a frame format of the A-control subfield according to one embodiment of the present application. [Figure 9c] 2 is a schematic diagram of a frame format of an EML control field according to an embodiment of the present application; [Figure 10a] FIG. 13 is a schematic diagram of another frame format of the AAR control subfield according to an embodiment of the present application. [Figure 10b] FIG. 13 is a schematic diagram of yet another frame format of the AAR control subfield according to an embodiment of the present application. [Figure 11a] FIG. 13 is a schematic diagram of another frame format of the A-control subfield according to an embodiment of the present application. [Figure 11b] FIG. 13 is a schematic diagram of yet another frame format of the A-control subfield according to an embodiment of the present application. [Figure 12a] FIG. 2 is a schematic diagram of another frame format of an EML control field according to an embodiment of the present application; [Figure 12b] FIG. 13 is a schematic diagram of yet another frame format of an EML control field according to an embodiment of the present application; [Figure 13] 11 is a third schematic flowchart of a link state indication method in EMLSR mode according to an embodiment of the present application; [Figure 14] 4 is a schematic flowchart of a frame type indication method in EMLSR mode according to an embodiment of the present application; [Figure 15] A schematic diagram of a frame format of a user information field in a MU-RTS frame or a BSRP frame according to one embodiment of the present application. [Figure 16]4 is another schematic flowchart of a frame type indication method in EMLSR mode according to an embodiment of the present application; [Figure 17] A schematic diagram of a frame format of a common information field in a MU-RTS frame or a BSRP frame according to one embodiment of the present application. [Figure 18] 1 is a schematic diagram of the structure of a communication device according to an embodiment of the present application; [Figure 19] 1 is a schematic diagram of the structure of a communication device 1000 according to an embodiment of the present application. [Figure 20] 2 is a schematic flowchart of a link status indication method in an NSTR link pair according to an embodiment of the present application; [Figure 21a] A schematic diagram of a frame format of the A-control subfield according to one embodiment of the present application. [Figure 21b] FIG. 13 is a schematic diagram of another frame format of the A-control subfield according to an embodiment of the present application. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0135] The following clearly and completely describes the technical solutions of the embodiments of the present application with reference to the accompanying drawings of the embodiments of the present application.

[0136] In the description of this application, unless otherwise specified, " / " means "or". For example, A / B can refer to A or B. The term "and / or" in this specification describes only the association relationship between related objects and indicates that three relationships may exist. For example, A and / or B can represent the following three cases: when only A exists, when both A and B exist, and when only B exists. In addition, "at least one" means one or more, and "multiple" means two or more. At least one of the following items (elements) or similar expressions refers to any combination of those items (elements), including any combination of one item (element) or multiple items (elements). For example, at least one of a, b, or c can represent a, b, c, a and b, a and c, b and c, or a, b, and c. a, b, and c may each be singular or plural.

[0137] In the description of this application, terms such as "first" and "second" do not limit the quantity or order of execution, and terms such as "first" and "second" do not indicate clear distinctions.

[0138] The terms "example" or "for example" are used in this application to denote providing an example, illustration, or explanation. Any embodiment or design scheme described in this application as an "example," "such as," or "for example" should not be described as preferred or having more advantages over another embodiment or design scheme. Strictly, use of words such as "example," "in one example," "for example," and the like are intended to present the relevant concept in a concrete manner.

[0139] It should be understood that in this application, "when" and "if" refer to the device performing the corresponding processing in a target situation and are not intended to be time-limited. These terms do not imply that the device is required to have a deterministic operation during implementation, nor do they imply any other limitations.

[0140] In this application, elements referred to in the singular are intended to denote "one or more" but not "one and only one," unless otherwise specified.

[0141] In the embodiment of the present application, it should be understood that "B corresponding to A" indicates that B is associated with A and B can be determined based on A. However, it should be further understood that determining B based on A does not mean that B is determined based only on A. B can alternatively be determined based on A and / or other information.

[0142] In order to facilitate understanding of the method provided in the embodiment of the present application, the following describes the system architecture of the method provided in the embodiment of the present application. It should be understood that the system architecture described in the embodiment of the present application is intended to more clearly describe the technical solutions in the embodiment of the present application, and does not constitute any limitations on the technical solutions provided in the embodiment of the present application.

[0143] The technical solution provided in this application may be applied to a wireless communication system, for example, a wireless local area network system. The technical solution provided in this application may be implemented by a communication device in the wireless communication system, or a chip or processor in the communication device. The communication device may be a wireless communication device that supports parallel transmission on multiple links. For example, the communication device may be called a multi-link device (MLD) or a multi-band device. Compared with a communication device that only supports single-link transmission, the multi-link device has higher transmission efficiency and a larger throughput rate.

[0144] A multilink device includes one or more affiliated stations (STAs). An affiliated station is a logical station and may operate over a link, a frequency band, or a channel. An affiliated station may be an access point (AP) or a non-access point station (non-AP STA). In 802.11be, a multilink device whose affiliated station is an AP is called an AP multilink device (AP MLD), and a multilink device whose affiliated station is a non-AP STA is called a non-AP multilink device (non-AP MLD).

[0145] Optionally, one multilink device may include multiple logical stations. Each logical station operates on a link, but multiple logical stations are allowed to operate on the same link. During data transmission between the AP MLD and the non-AP MLD, a link identifier may be used to identify a link or a station on the link. Before communication, the AP MLD and the non-AP MLD may first negotiate or communicate with each other about the correspondence between the link identifier and the link or a station on the link. Therefore, during data transmission, the link identifier is carried without transmitting a large amount of signaling information to indicate the link or a station on the link. This reduces signaling overhead and improves transmission efficiency.

[0146] In one example, a management frame, such as a beacon frame or an association request frame, transmitted when an AP MLD establishes a basic service set (BSS) carries an element, which includes multiple link identifier information fields. The link identifier information field may indicate a correspondence between a link identifier and a station operating on a link corresponding to the link identifier. A link identifier information field includes a link identifier and includes one or more of the following information: a medium access control (MAC) address, an operation class, and a channel number. The MAC address, the operation class, and the channel number may indicate a link. In the case of an AP, the MAC address of the AP is the BSSID (basic service set identifier) ​​of the AP. In another example, in the association process between multi-link devices, the AP MLD and the non-AP MLD negotiate multiple link identifier information fields. A multi-link association refers to one association between an AP in an AP MLD and a STA in a non-AP MLD. The association may facilitate separate associations between multiple STAs in a non-AP MLD and multiple APs in an AP MLD, with one STA associated with one AP. One or more STAs in a non-AP MLD may establish association relationships with, and then communicate with, one or more APs in an AP MLD.

[0147] Optionally, the multilink device may implement wireless communication in accordance with the IEEE 802.11 series protocol. For example, a station that is compliant with ultra-high throughput or a station that is compliant with or compatible with IEEE 802.11be implements communication with another device. Of course, the other device may or may not be a multilink device.

[0148] The technical solutions provided in the present application may be applied to a scenario in which one node communicates with one or more nodes, a single-user uplink / downlink communication scenario, a multi-user uplink / downlink communication scenario, or a device to device (D2D) communication scenario. In the embodiments of the present application, the term "communication" may also be described as "data transmission", "information transmission", or "transmission". The term "transmission" may generally refer to sending and receiving.

[0149] Any one of the above-mentioned nodes may be an AP MLD or a non-AP MLD. For example, the technical solution provided in this application is applied to a scenario in which an AP MLD and a non-AP MLD communicate with each other. Optionally, one or more nodes in the above-mentioned nodes may be a legacy station that only supports transmission on a single link. That is, in the above-mentioned communication scenario, in addition to a multi-link device, a single-link device such as a single-link STA may also be included.

[0150] FIG. 1 is a schematic diagram of an architecture of a wireless communication system according to an embodiment of the present application. As shown in FIG. 1, the wireless communication system includes at least one AP MLD (e.g., AP MLD 100 in FIG. 1) and at least one non-AP MLD (e.g., non-AP MLD 200 and non-AP MLD 300 in FIG. 1). Optionally, FIG. 1 further includes a legacy station that supports transmission only on a single link (e.g., single-link non-AP STA 400 in FIG. 1, also called STA 400). The AP MLD is a multi-link device that serves the non-AP MLD, and the non-AP MLD may communicate with the AP MLD on multiple links to implement improved throughput. An AP in the AP MLD may communicate with a STA in the non-AP MLD on one link. Of course, the AP MLD (in the AP) may serve legacy stations, and the non-AP MLD (in the STA) may conduct peer-to-peer (P2P) communication with the legacy stations. It will be understood that the number of AP MLDs, non-AP MLDs, and legacy stations (i.e., single-link non-AP STAs) in FIG. 1 are merely examples.

[0151] FIG. 2a is a schematic diagram of a structure of a multi-link device according to an embodiment of the present application. The 802.11 standard focuses on the 802.11 physical layer (PHY) part and the medium access control (MAC) layer part in the multi-link device. As shown in FIG. 2a, the multiple STAs included in the multi-link device are independent of each other in the low MAC layer and the PHY layer, and are also independent of each other in the high MAC layer. FIG. 2b is a schematic diagram of another structure of a multi-link device according to an embodiment of the present application. As shown in FIG. 2b, the multiple STAs included in the multi-link device are independent of each other in the low MAC layer and the PHY layer, and share the high MAC layer. Of course, in the multi-link communication process, non-AP MLD may use a structure with an independent upper MAC layer, AP MLD may use a structure with a shared upper MAC layer, or non-AP MLD may use a structure with a shared upper MAC layer, AP MLD may use a structure with an independent upper MAC layer, or both non-AP MLD and AP MLD may use a structure with a shared upper MAC layer, or both non-AP MLD and AP MLD may use a structure with an independent upper MAC layer. The schematic diagram of the internal structure of the multi-link device is not limited in the embodiment of the present application. Figure 2a and Figure 2b are merely examples for explanation. For example, the upper MAC layer or the lower MAC layer may be implemented by one processor in the chip system of the multi-link device, or may be implemented by different processing modules in the chip system.

[0152] For example, the multi-link device in the embodiment of the present application may be a single antenna device or a multi-antenna device. For example, the multi-link device may be a device having three or more antennas. The number of antennas included in the multi-link device is not limited in the embodiment of the present application.

[0153] 3 is a schematic diagram of multi-link communication according to an embodiment of the present application. As shown in FIG. 3, the AP MLD includes n stations, which are AP 1, AP 2, ..., and AP n. The non-AP MLD also includes n stations, which are STA 1, STA 2, ..., and STA n. The AP MLD and the non-AP MLD may implement parallel communication for link 1, link 2, ..., link n. An AP in the AP MLD may establish an association relationship with a STA in the non-AP MLD. For example, STA1 in the non-AP MLD establishes an association relationship with AP1 in the AP MLD. STA2 in the non-AP MLD establishes an association relationship with AP2 in the AP MLD. STAn in the non-AP MLD establishes an association relationship with APn in the AP MLD.

[0154] For example, a multi-link device (which may be a non-AP MLD or an AP MLD in this specification) is a device having a wireless communication function. The device may be an entire system device, or a chip, a processing system, etc. installed in the entire system device. The device in which the chip or processing system is installed may realize the method and function in the embodiment of the present application under the control of the chip or processing system. For example, in the embodiment of the present application, the non-AP MLD may have a wireless transceiver function, support 802.11 series protocols, and communicate with an AP MLD or another non-AP MLD. For example, the non-AP MLD is any user communication device that allows a user to communicate with an AP and communicate with a WLAN. For example, the non-AP MLD may be a user equipment that can connect to a network, such as a tablet computer, a desktop computer, a laptop computer, a notebook computer, an ultra-mobile personal computer (UMPC), a handheld computer, a netbook, a personal digital assistant (PDA), a mobile phone, an Internet of Things node in the Internet of Things, an in-vehicle communication device in the Internet of Vehicles, etc. The non-AP MLD may alternatively be a chip and processing system in the aforementioned terminal. The AP MLD in the embodiment of the present application is a device that provides services to the non-AP MLD and may support the 802.11 series protocol. For example, the AP MLD may be a communication entity such as a communication server, a router, a switch, or a bridge, and the AP MLD may include various forms of macro base stations, micro base stations, relay stations, etc. Of course, the AP MLD may alternatively be a chip and processing system in various forms of devices. In this way, the methods and functions in the embodiments of the present application are implemented.

[0155] It should be understood that the multi-link device may support high-rate and low-latency transmission. With the continuous development of application scenarios of wireless local area networks, the multi-link device may be further applied to more scenarios, such as sensor nodes in smart cities (smart meters, smart electric meters, smart air detection nodes, etc.), smart devices in smart homes (smart cameras, projectors, displays, televisions, stereos, refrigerators, washing machines, etc.), nodes in Internet of Things, entertainment terminals (AR, VR, or other wearable devices, etc.), smart devices in smart offices (printers, projectors, etc.), Internet of Vehicles devices in Internet of Vehicles, and some infrastructures in daily life scenarios (vehicles, vending machines, supermarket self-service navigation terminals, self-service cash register devices, self-service ordering machines). The specific forms of non-AP MLD and AP MLD are not limited in the embodiments of this application, and are merely examples for explanation herein. The 802.11 protocol may be a protocol that supports 802.11be or is compatible with 802.11be.

[0156] The above briefly describes the system structure in the embodiment of the present application. In order to better understand the technical solution of the present application, the following briefly describes the content related to the present application.

[0157] 1. Spatial streams and antennas A radio transmits multiple signals simultaneously, and each signal is called a spatial stream. In a multiple input multiple output (MIMO) system, the number of spatial streams is usually equal to or less than the number of antennas. If the number of antennas at the transmitting end is different from the number of antennas at the receiving end, the number of spatial streams is equal to or less than the minimum number of antennas at the transmitting end or the receiving end. For example, a 4×4 (four transmitting antennas and four receiving antennas, also called four inputs and four outputs) MIMO system may be used to transmit four or less spatial streams, and a 3×2 (three transmitting antennas and two receiving antennas) MIMO system may transmit two or less spatial streams.

[0158] Optionally, the relationship between antennas and spatial streams in a MIMO system may be further used in this application.

[0159] 2.The process of communication between non-AP MLD and AP MLD in EMLSR mode FIG. 4 is a schematic diagram of communication between non-AP MLD and AP MLD in EMLSR mode. Non-AP MLD in EMLSR mode performs reception on each link via one antenna (or single radio). That is, non-AP MLD in EMLSR mode performs listening operation (i.e., CCA) on the channel via one antenna on each link. In addition, non-AP MLD in EMLSR mode can receive initial control frames transmitted by AP MLD of OFDM PPDU type and non-HT duplicate PPDU type on each link via one antenna, and reception of other types of frames is not supported. It should be understood that if the transmitting end uses one antenna to transmit on the link and the receiving end also uses one antenna to receive on the link, a 1×1 (one input, one output) antenna configuration is provided for the link. If the transmitting end uses two antennas to transmit on the link and the receiving end also uses two antennas to receive on the link, a 2×2 (two input, two output) antenna configuration is provided for the link. As shown in FIG. 4, the AP transmits an initial control frame, such as a multi-user (MU) request to send (RTS) frame, on channel 2 (ch2) through one antenna. The initial control frame includes a channel switch signal, which indicates the STA to switch antennas for reception. The STA receives the initial control frame transmitted by the AP (in this case, a 1×1 antenna configuration is formed on channel 2) on channel 2 through one antenna, replies with a clear to send (CTS) frame on channel 2, and switches the receiving antenna (radio) on channel 1 (ch1) to channel 2 in a timely manner based on the instruction of the channel switch signal in the initial control frame to form a 2×2 antenna configuration, and then performs downlink data transmission on channel 2 using the 2×2 antenna configuration.

[0160] The initial control frame is in OFDM PPDU format or non-HT duplicate PPDU format, and the rate meets one of 6 Mbps, 12 Mbps, or 24 Mbps. The initial control frame is a multi-user (MU) request to send (MU-RTS) frame or a buffer status report poll (BSRP) frame. A non-AP MLD operating in EMLSR mode supports receiving MU-RTS and BSRP frames, and only one spatial stream can be used when a non-AP MLD in EMLSR mode responds to an initial control frame (e.g., a BSRP frame).

[0161] Optionally, there may be two different antenna capability configurations for non-AP MLD in EMLSR mode. One is a symmetric antenna capability configuration for non-AP MLD in EMLSR mode. Specifically, the antenna capability configuration is that there is one antenna for each link, and the receiving capability of each antenna is limited. That is, only some types of PPDUs can be received, that is, each antenna is a limited antenna. The other is an asymmetric antenna capability configuration for non-AP MLD in EMLSR mode. Specifically, the antenna capability configuration is that there is one antenna for each link, and one antenna (called a common antenna) has a stronger receiving capability, which may be expressed as this antenna can receive all types of PPDUs, and another antenna (called a limited antenna) has a weaker receiving capability, that is, it can only receive some types of PPDUs. The link where the common antenna is deployed may be called a RX full capability link, and the link where the limited antenna is deployed may be called a RX limitation link.

[0162] In this application, for ease of explanation, "non-AP MLD in EMLSR mode (operating)" is denoted as "EMLSR non-AP MLD". In other words, EMLSR non-AP MLD may indicate that one or more links (stations) of the non-AP MLD enter EMLSR mode. Similarly, "station entering EMLSR mode in EMLSR non-AP MLD" may be denoted as "EMLSR STA".

[0163] Based on the above and the relevant descriptions in the current standards, there are at least the following problems in the EMLSR mode:

[0164] In the case of an AP MLD associated with an EMLSR non-AP MLD (for ease of explanation, the "AP MLD associated with an EMLSR non-AP MLD" is hereinafter referred to as the "associated AP MLD" for short), the entire EMLSR non-AP MLD or the EMLSR STA may be unavailable for some reasons (e.g., coexistence of different devices or different technologies). For example, an EMLSR STA in an EMLSR non-AP MLD communicates with another non-AP MLD or another single-link STA on the current link (i.e., the link on which the EMLSR STA operates) using a non-Wi-Fi technology such as Bluetooth. In this case, the resources of the current link are occupied; that is, the EMLSR STA is in a busy state, and the associated AP MLD cannot communicate with the EMLSR non-AP MLD on the link (e.g., cannot send an initial control frame). In other words, when the entire EMLSR non-AP MLD is unavailable, the associated AP MLD cannot communicate with the EMLSR non-AP MLD. Similarly, when some links of the EMLSR non-AP MLD or STAs on these links are unavailable, the associated AP MLD cannot communicate with the EMLSR non-AP MLD on these links. However, according to existing standards and technologies, the AP MLD does not know whether the EMLSR non-AP MLD currently associated with the AP MLD is unavailable. Therefore, when the AP MLD wants to communicate with the EMLSR non-AP MLD or one or more STAs in the EMLSR non-AP MLD, the AP MLD sends an initial control frame to the EMLSR non-AP MLD or one or more STAs in the EMLSR non-AP MLD.However, because the link resource or antenna resource is occupied, the EMLSR non-AP MLD or one or more STAs in the EMLSR non-AP MLD cannot correctly receive the initial control frame sent by the AP MLD, and therefore cannot respond to the initial control frame. Because the AP MLD does not receive a response to the initial control frame, the AP MLD may repeatedly send the initial control frame. Each time before sending the initial control frame, the AP MLD implements channel contention to obtain channel resources for sending the initial control frame. This causes resource waste.

[0165] As another example, if the EMLSR non-AP MLD wants to receive a group addressed frame at the next target beacon transmission time (TBTT) of a link, the EMLSR non-AP MLD needs to switch the antenna / spatial stream on another link to the link to receive before the next TBTT arrives. Alternatively, the AP MLD associated with the EMLSR non-AP MLD needs to advance at least one transition delay to stop the frame exchange initiated by the AP MLD on another link, so that the antenna / spatial stream on the other link can be switched to the link that is ready to transmit the group addressed frame. However, according to the existing protocol, the AP MLD does not know which link the EMLSR non-AP MLD is ready to receive the group addressed frame on which TBTT. Therefore, the AP MLD may transmit an initial control frame on some unavailable links within the time that the EMLSR non-AP MLD receives the group addressed frame, causing a waste of resources.

[0166] An embodiment of the present application provides a link status indication method in EMLSR mode. When the EMLSR non-AP MLD or the entire EMLSR STA on the EMLSR non-AP MLD link is temporarily unavailable for some reason (e.g., multiple devices or multiple technologies coexist, or the EMLSR non-AP MLD wants to receive the next TBTT group addressed frame on the link), the EMLSR non-AP MLD can notify the AP MLD associated with the EMLSR non-AP MLD of the status change of the EMLSR non-AP MLD link. When the entire EMLSR non-AP MLD ends the unavailability, or when the EMLSR STA on the EMLSR non-AP MLD link ends the unavailability and is ready to resume listening mode, the EMLSR non-AP MLD can also notify the associated AP MLD. Therefore, the AP MLD knows the link status changes of the EMLSR non-AP MLD associated with the AP MLD in a timely manner, and the AP MLD does not send initial control frames on the unavailable links of the EMLSR non-AP MLD to reduce resource waste.

[0167] The following describes in detail the technical solutions provided in this application with reference to further accompanying drawings.

[0168] The technical solutions provided in this application are described by using multiple embodiments. For details, please refer to the following description. It should be understood that the technical solutions described in the embodiments of this application may be any combination to form new embodiments, and parts related to the same or similar concepts or solutions may be mutually referenced or combined. The following describes the embodiments in detail and individually.

[0169] It should be understood that both the AP MLD and the EMLSR non-AP MLD in the present application support the 802.11be protocol (also called Wi-Fi 7 or EHT protocol) and may further support another WLAN communication protocol, such as 802.11ax or 802.11ac. It should be understood that the AP MLD and the EMLSR non-AP MLD in the present application may further support the next-generation protocol of 802.11be. That is, the method provided in the present application is applicable not only to the 802.11be protocol but also to the next-generation protocol of 802.11be.

[0170] Optionally, "disabled", "unavailable", etc. in this application are all relative to the AP MLD. For example, "EMLSR non-AP MLD is disabled" in this application means that the EMLSR non-AP MLD cannot be used for the associated AP MLD, or the associated AP MLD cannot communicate with the EMLSR non-AP MLD, or for the associated AP MLD, the EMLSR non-AP MLD does not receive and does not respond to uplink trigger frames. However, the EMLSR non-AP MLD may communicate with another non-AP MLD or single-link STA. That is, the EMLSR non-AP MLD is still available for another non-AP MLD or single-link STA. Similarly, "EMLSR links are disabled" and "EMLSR non-AP MLD unavailable links" in this application mean that these links are unavailable or occupied for the associated AP MLD, or the associated AP MLD cannot communicate with the EMLSR non-AP MLD on these links, or for the associated AP MLD, the EMLSR non-AP MLD cannot receive or respond to uplink trigger frames on these links. However, the EMLSR non-AP MLD may communicate with another non-AP MLD or single-link STA on these links. That is, these links of the EMLSR non-AP MLD are still available for another non-AP MLD or single-link STA.

[0171] Optionally, a non-AP MLD may operate in the EMLSR mode on a specified set of the enabled links between the non-AP MLD and its associated AP MLD. The specified set of the enabled links in which the EMLSR mode is applied is called EMLSR links. In other words, an "EMLSR link" in this application may be a link used for EMLSR mode by a non-AP MLD, or a link that enters EMLSR mode in a non-AP MLD, or a link on which a listening operation is performed in a non-AP MLD or a link in listening mode, etc.

[0172] EMBODIMENT 1 This embodiment of the present application mainly describes how the EMLSR non-AP MLD notifies the EMLSR non-AP MLD of its associated AP MLDs when the entire EMLSR non-AP MLD is temporarily unavailable for some reason, and / or how the EMLSR non-AP MLD notifies the EMLSR non-AP MLD of its associated AP MLDs when the entire EMLSR non-AP MLD ends its unavailability or when an EMLSR STA on the EMLSR non-AP MLD's link ends its unavailability and is ready to resume listening mode.

[0173] For example, the reason why the entire EMLSR non-AP MLD is unavailable is because the EMLSR non-AP MLD has only two links, and the antenna of one link is switched to another link to communicate with another non-AP MLD or STA. In this case, for the AP MLD, the entire EMLSR non-AP MLD is unavailable. Alternatively, the EMLSR non-AP MLD has multiple links. The EMLSR STAs on some links are unavailable, and the ability of the EMLSR STAs on the remaining links is also affected. The initial control frame sent by the AP MLD cannot be received correctly. The reason why the entire EMLSR non-AP MLD is unavailable is not limited in this application.

[0174] 5 is a first schematic flowchart of a link status indication method in EMLSR mode according to an embodiment of the present application. In this embodiment of the present application, the antenna capability configuration of EMLSR non-AP MLD can be symmetric or asymmetric. This is not limited in this embodiment of the present application. As shown in FIG. 5, the link status indication method in EMLSR mode includes, but is not limited to, the following steps:

[0175] S101: EMLSR non-AP MLD generates a first frame, where the first frame includes first indication information, and the first indication information indicates that the EMLSR non-AP MLD is disabled.

[0176] S102: EMLSR non-AP MLD sends a first frame.

[0177] Optionally, when the EMLSR non-AP MLD confirms that all links (or STAs on all links) of the EMLSR non-AP MLD are unavailable due to the AP MLD associated with the EMLSR non-AP MLD (e.g., the EMLSR non-AP MLD has only two links, and an antenna of one link should be switched to another link to communicate with another non-AP MLD or STA), the EMLSR non-AP MLD may generate a first frame. The first frame may carry a first indication information indicating that the EMLSR non-AP MLD is disabled. The EMLSR non-AP MLD transmits the first frame on any available link. It should be understood that after the EMLSR non-AP MLD transmits the first frame, or after a period of time after the EMLSR non-AP MLD transmits the first frame, the entire EMLSR non-AP MLD is unavailable to the AP MLD associated with the EMLSR non-AP MLD.

[0178] The first frame may be a data frame.

[0179] S103: The AP MLD receives a first frame.

[0180] S104: The AP MLD determines, according to the first indication information in the first frame, that the EMLSR non-AP MLD is disabled.

[0181] Optionally, the AP MLD associated with the EMLSR non-AP MLD receives the first frame and determines that the EMLSR non-AP MLD is disabled based on the first indication information carried in the first frame. After the AP MLD determines that the EMLSR non-AP MLD is disabled, the AP MLD may not transmit an initial control frame to the EMLSR non-AP MLD until the EMLSR non-AP MLD becomes available and resumes. In other words, when the AP MLD receives a notification indicating that the EMLSR non-AP MLD has entered an unavailable state (i.e., when the AP MLD receives the first frame carrying the first indication information), the AP MLD does not transmit an initial control frame to the EMLSR non-AP MLD until the AP MLD receives a notification indicating that the EMLSR non-AP MLD has become available and resumes.

[0182] In this embodiment of the present application, when the EMLSR non-AP MLD is temporarily unavailable for some reason, the link status (available or unavailable / disabled) of the EMLSR non-AP MLD is actively reported, so that the AP MLD can know the link status change of the EMLSR non-AP MLD associated with the AP MLD in a timely manner, and the AP MLD does not send a signal, such as an initial control frame, to the EMLSR non-AP MLD on the unavailable link of the EMLSR non-AP MLD to reduce resource waste. In addition, in this embodiment of the present application, a notification needs to be sent only once on one link to reduce overhead.

[0183] In an optional embodiment, after the EMLSR non-AP MLD becomes temporarily unavailable for some reason, the AP MLD cannot communicate with the EMLSR non-AP MLD. In contrast, the AP MLD can communicate with the EMLSR non-AP MLD only after the EMLSR non-AP MLD (link) resumes. However, according to the existing protocol, the AP MLD does not know whether the EMLSR non-AP MLD becomes available and resumes. Therefore, when the data of the EMLSR non-AP MLD exists in the buffer of the AP MLD, the AP MLD may continue to wait. The AP MLD does not know whether the EMLSR non-AP MLD becomes available and resumes, and as a result, the AP MLD and the EMLSR non-AP MLD cannot communicate normally.

[0184] Therefore, in this embodiment of the present application, after becoming available and resuming, the EMLSR non-AP MLD can actively notify the AP MLD, so that the AP MLD can communicate normally with the EMLSR non-AP MLD.

[0185] Optionally, this embodiment of the present application (steps S105 and S106 below) may be implemented separately. Naturally, this embodiment of the present application may be alternatively implemented with reference to the previous embodiment (steps S101 to S104), and FIG. 5 is reused. When this embodiment of the present application is implemented together with the previous embodiment, this embodiment of the present application may be implemented after step S104 or before step S101. This is not limited in this embodiment of the present application.

[0186] The link status indication method in EMLSR mode provided in this embodiment of the present application further includes the following steps.

[0187] S105: The EMLSR non-AP MLD sends a second frame, where the second frame includes second indication information, and the second indication information indicates that the EMLSR non-AP MLD is available.

[0188] S106: The AP MLD receives a second frame.

[0189] Optionally, after the EMLSR non-AP MLD enters an unavailable state, when the EMLSR non-AP MLD confirms that the link of the EMLSR non-AP MLD has become available and resumed, or the entire EMLSR non-AP MLD has become available and resumed, the EMLSR non-AP MLD may transmit a second frame to the AP MLD on the available and resumed link. In response, the AP MLD receives a second frame on the available and resumed link. The second frame may include second indication information. The second indication information may indicate that the EMLSR non-AP MLD (link) is available, or the second indication information indicates that the EMLSR non-AP MLD (link) resumes, or the second indication information indicates that the EMLSR non-AP MLD (link) switches back to listening operation. The second frame may be a data frame.

[0190] Optionally, after the EMLSR non-AP MLD transmits the second frame, i.e., after transmitting a notification indicating that the EMLSR non-AP MLD has resumed to an available state, the STAs in the EMLSR non-AP MLD may immediately switch to listening mode, or switch to listening mode after a specified time T (e.g., short interframe space, SIFS). If the link that becomes available and resumes in the EMLSR non-AP MLD is a reception-limited link, the AP MLD receiving the notification needs to wait at least one transition delay (the specific waiting duration may be the transition delay+the specified time T) before transmitting an initial control frame to the EMLSR STA that becomes available and resumes. If the link that becomes available and resumes in the EMLSR non-AP MLD is a reception-full-capability link, the AP MLD receiving the notification may directly transmit an initial control frame to the EMLSR STA that becomes available and resumes without waiting, or may transmit an initial control frame to the EMLSR STA that becomes available and resumes after the specified time T.

[0191] Optionally, when the antenna capability configuration of the EMLSR non-AP MLD is asymmetric and the receiving full capability link of the EMLSR non-AP MLD is available, the AP MLD may send an MU-RTS frame or a BSRP frame carrying indication information to the EMLSR non-AP MLD to indicate whether the MU-RTS frame or the BSRP frame is an initial control frame or whether the MU-RTS frame or the BSRP frame received by the station is an initial control frame. Specifically, for possible implementation forms of the indication information, please refer to the following description of embodiment 4 and embodiment 5. Details are not described in this specification.

[0192] In this embodiment of the present application, when the entire EMLSR non-AP MLD ends unavailability, or when an EMLSR STA on the link of the EMLSR non-AP MLD ends unavailability and is ready to resume to listening mode, the AP MLD is notified using the second indication information, so that the AP MLD knows the available link of the EMLSR non-AP MLD in a timely manner, and the AP MLD schedules the EMLSR non-AP MLD to perform uplink transmission or send downlink data to the EMLSR non-AP MLD.

[0193] The above describes the possible procedures of this embodiment of the present application. In the following, the possible implementation forms of the first indication information and the second indication information will be described separately.

[0194] It will be understood that for single-link devices, multi-device or multi-technology coexistence issues can be resolved using an operating mode (OM) control subfield. Specifically, before communicating with another station, a single-link STA may inform its associated AP of the type of trigger-based uplink multi-user transmission currently supported by the STA by adding an OM control subfield to a data frame. Figure 6 is a schematic diagram of a frame format of an OM control subfield according to an embodiment of the present application. As shown in Figure 6, the OM control subfield includes, but is not limited to, an uplink (UL) multi-user (MU) disable (UL MU Disable) subfield and an uplink multi-user data disable (UL MU Data Disable) subfield. The UL MU Disable subfield and the UL MU Data Disable subfield may jointly / collaboratively indicate whether a single-link non-AP STA can respond to different types of trigger frames sent by the AP side. Specifically, when the UL MU Disable subfield is set to 0 and the UL MU Data Disable subfield is also set to 0, this indicates that the STA allows and responds to all types of trigger frames. When the UL MU Disable subfield is set to 0 and the UL MU Data Disable subfield is set to 1, this indicates that if the STA receives a basic trigger frame, the STA does not respond with an uplink multi-user data frame, but if the STA receives another type of trigger frame, the STA may perform uplink multi-user transmission.When the UL MU Disable subfield is set to 1 and the UL MU Data Disable subfield is set to 0, this indicates that the STA will not perform uplink multi-user transmission, regardless of the type of trigger frame received by the STA. When the UL MU Disable subfield is set to 1 and the UL MU Data Disable subfield is set to 1, the subfields are reserved.

[0195] In a first implementation form, the first indication information and the second indication information may be represented using different values ​​of the same field.

[0196] Specifically, the first indication information and the second indication information may be placed in the EHT OM control subfield of the high throughput (HT) control field. The EHT OM control subfield is an extension of the OM Control subfield in the EHT background. For example, a reserved bit in the EHT OM control subfield may be used as a subfield, and different values ​​of the subfield may indicate the first indication information and the second indication information. For ease of explanation, the newly added subfield in the EHT OM control subfield is called the Multilink Device Disable / Resume (MLD Disable / Resume) subfield. Of course, the newly added subfield may also have another name. This is not limited in this embodiment of the present application. It should be understood that the UL MU Disable subfield and the UL MU Data Disable subfield in the OM control subfield may indicate whether the STA responds to some trigger frames in the case of a single link. Therefore, the usage rule of the MLD Disable / Resume subfield needs to be differentiated from the case of a single link.

[0197] Figure 7a is a schematic diagram of a frame format of an OM Control subfield and an EHT OM control subfield in an HT Control field according to an embodiment of the present application. As shown in Figure 7a, the EHT OM control subfield includes, but is not limited to, a 1-bit MLD Disable / Resume subfield. When the MLD Disable / Resume subfield is set to 1, it indicates the first indication information, indicating that the EMLSR non-AP MLD is disabled. In this case, all or part of the OM Control subfield may be reserved in the HT Control field. If the UL MU Disable subfield and the UL MU Data Disable subfield exist, both the UL MU Disable subfield and the UL MU Data Disable subfield are set to 1. Of course, in this case, the HT Control field may not include the OM Control subfield.

[0198] When the MLD Disable / Resume subfield is set to 0, it indicates a second indication information, indicating that all links of the EMLSR non-AP MLD are available, or indicating that all links of the EMLSR non-AP MLD resume from an unavailable state, or indicating that all links of the EMLSR non-AP MLD switch back to listening operation. In this case, all or part of the OM Control subfield may be reserved in the HT Control field. If the UL MU Disable subfield and the UL MU Data Disable subfield are present, both the UL MU Disable subfield and the UL MU Data Disable subfield are set to 1. Of course, in this case, the HT Control field may not include the OM Control subfield.

[0199] Optionally, the HT Control field includes an OM Control subfield and an EHT OM control subfield. The OM Control subfield includes a UL MU Disable subfield and a UL MU Data Disable subfield, and the EHT OM control subfield includes an MLD Disable / Resume subfield. When the MLD Disable / Resume subfield is set to 0 and both the UL MU Disable subfield and the UL MU Data Disable subfield are set to 0, the subfields jointly indicate that the first link of the EMLSR non-AP MLD is available (resuming from unavailable) or that the first link of the EMLSR non-AP MLD returns to listening operation. The first link is the link used by the EMLSR non-AP MLD to transmit the second frame. That is, when the MLD Disable / Resume subfield is set to 0, and the UL MU Disable subfield and the UL MU Data Disable subfield are both set to 0, this indicates that the EMLSR non-AP MLD link resumes from an unavailable state, and this link is the link for transmitting the second frame.

[0200] It should be understood that when the OM Control subfield indicates a different behavior of the STA in the case of a single link, i.e., when the original functionality of the STA is implemented, the EHT OM control subfield may not include the MLD Disable / Resume subfield.

[0201] It should be further understood that the names and lengths of the subfields in the frame format shown in Figure 7a are examples, which are not limiting in this embodiment of the present application.

[0202] In this embodiment of the present application, a 1-bit MLD Disable / Resume subfield is added to the EHT OM Control subfield of the HT Control field to indicate that the EMLSR non-AP MLD is disabled and the EMLSR non-AP MLD resumes from unavailable to listening mode, so that the AP MLD can know the status change of the link of the EMLSR non-AP MLD associated with the AP MLD in a timely manner, and the AP MLD will not send an initial control frame on the unavailable link of the EMLSR non-AP MLD to reduce resource waste.

[0203] In a second implementation, the first indication information and the second indication information are implemented using different fields.

[0204] Specifically, the first indication information and the second indication information can be disposed in an EHT OM control subfield of the HT control field. For example, the first indication information may be carried in a reserved bit in the EHT OM control subfield. For ease of description, the reserved bit is called a multilink device disable (MLD Disable) subfield. Of course, the reserved bit may have another name. This is not limited in this embodiment of the present application. The second indication information is carried in another reserved bit in the EHT OM control subfield. For ease of description, the reserved bit is called a multilink device resume (MLD Resume) subfield. Of course, the reserved bit may have another name. This is not limited in this embodiment of the present application.

[0205] Figure 7b is a schematic diagram of another frame format of the OM Control subfield and the EHT OM control subfield in the HT Control field according to an embodiment of the present application. As shown in Figure 7b, the EHT OM control subfield includes, but is not limited to, a 1-bit MLD Disable subfield (i.e., first indication information) and a 1-bit MLD Resume subfield (i.e., second indication information). When the MLD Disable subfield is set to 1, it indicates that the EMLSR non-AP MLD is disabled. In this case, all or part of the OM Control subfield may be reserved in the HT Control field. If the UL MU Disable subfield and the UL MU Data Disable subfield exist, both the UL MU Disable subfield and the UL MU Data Disable subfield are set to 1. Of course, in this case, the HT Control field may not include the OM Control subfield. Optionally, when the MLD Disable subfield is set to 0, it indicates that the subfield is reserved.

[0206] When the MLD Resume subfield is set to 1, it indicates that all links of the EMLSR non-AP MLD are available, or indicates that all links of the EMLSR non-AP MLD resume from an unavailable state, or indicates that all links of the EMLSR non-AP MLD switch back to listening operation. In this case, all or part of the OM Control subfield may be reserved in the HT Control field. If the UL MU Disable subfield and the UL MU Data Disable subfield are present, both the UL MU Disable subfield and the UL MU Data Disable subfield are set to 1. Of course, in this case, the HT Control field may not include the OM Control subfield. Optionally, when the MLD Resume subfield is set to 0, it indicates that the subfield is reserved.

[0207] Optionally, the HT Control field includes an OM Control subfield and an EHT OM control subfield. The OM Control subfield includes a UL MU Disable subfield and a UL MU Data Disable subfield, and the EHT OM control subfield includes an MLD Disable subfield and an MLD Resume subfield. When the MLD Resume subfield is set to 1 and both the UL MU Disable subfield and the UL MU Data Disable subfield are set to 0, the subfields jointly indicate that the first link of the EMLSR non-AP MLD is available (resumes from unavailable) or that the first link of the EMLSR non-AP MLD returns to listening operation. The first link is the link used by the EMLSR non-AP MLD to transmit the second frame. That is, when the MLD Resume subfield is set to 1, and both the UL MU Disable subfield and the UL MU Data Disable subfield are set to 0, this indicates that the EMLSR non-AP MLD link resumes from a disabled state, and this link is the link for transmitting the second frame.

[0208] It should be understood that when the OM Control subfield indicates a different behavior of the STA in the case of a single link, i.e., when the original functionality of the STA is implemented, the EHT OM control subfield may not include the MLD Disable subfield or the MLD Resume subfield.

[0209] It should be further understood that the names and lengths of the subfields in the frame format shown in Figure 7b are examples, which are not limiting in this embodiment of the present application.

[0210] In this embodiment of the present application, a 1-bit MLD Disable subfield is added to the EHT OM control subfield to indicate that the EMLSR non-AP MLD is disabled, and a 1-bit Resume subfield is further added to indicate that the EMLSR non-AP MLD resumes from unavailable to listening mode. The meaning of the subfields is clear.

[0211] EMBODIMENT 2 This embodiment of the present application mainly describes how the EMLSR non-AP MLD explicitly notifies the EMLSR non-AP MLD of its associated AP MLD when the EMLSR non-AP MLD or an EMLSR STA on the EMLSR non-AP MLD's link is temporarily unavailable for some reason, or when the EMLSR STA ends its unavailability and is ready to resume listening mode.

[0212] 8 is a second schematic flowchart of a link status indication method in EMLSR mode according to an embodiment of the present application. In this embodiment of the present application, the antenna capability configuration of EMLSR non-AP MLD can be symmetric or asymmetric. This is not limited in this embodiment of the present application. As shown in FIG. 8, the link status indication method in EMLSR mode includes, but is not limited to, the following steps:

[0213] S201: The EMLSR non-AP MLD generates a third frame, the third frame includes fourth indication information, and the fourth indication information indicates an available link or a link whose status is changing in the EMLSR non-AP MLD.

[0214] S202: EMLSR non-AP MLD sends a third frame.

[0215] Optionally, when the EMLSR non-AP MLD determines that the status of all or some of the links of the EMLSR non-AP MLD has changed, e.g., for an AP MLD associated with the EMLSR non-AP MLD, when at least one link of the EMLSR non-AP MLD (station) is unavailable or resumes from unavailable to listening mode, the EMLSR non-AP MLD may generate a third frame. The third frame may carry fourth indication information, and may optionally further carry third indication information. The third indication information may indicate that the link status of the non-AP MLD has changed, and the non-AP MLD is a non-AP MLD that supports the EMLSR mode. The fourth indication information may indicate available links or links whose status has changed within the EMLSR non-AP MLD. The EMLSR non-AP MLD may further transmit the third frame on any available links. Optionally, the state of the EMLSR non-AP MLD link changes only after the EMLSR non-AP MLD transmits the third frame or a certain period of time after the EMLSR non-AP MLD transmits the third frame. Alternatively, the state of the EMLSR non-AP MLD link may change only before the EMLSR non-AP MLD transmits the third frame or a certain period of time before the EMLSR non-AP MLD transmits the third frame.

[0216] Optionally, the non-AP MLD link state change includes, but is not limited to, the EMLSR link being disabled and the EMLSR non-AP MLD unavailable link changing to an available EMLSR link.

[0217] In order to better understand the indication manner of the third indication information and the fourth indication information, the following uses an example to describe possible implementation forms of the third indication information and the fourth indication information.

[0218] Implementation form 1 The third indication information may indicate that the state of the link of the non-AP MLD has changed, and the fourth indication information may indicate the available link of the EMLSR non-AP MLD (EMLSR link). For example, the fourth indication information may indicate the available link of the EMLSR non-AP MLD using a bitmap. That is, one bit in the bitmap corresponds to one link. When a bit in the bitmap is set to 1, it indicates that the link corresponding to the bit is an available link. Alternatively, the fourth indication information may indicate the available link of the EMLSR non-AP MLD using a link identifier (link ID). That is, the link identified by the link identifier is an available link. This is not limited in this embodiment of the present application.

[0219] Optionally, the third indication information and the fourth indication information can be placed in an AP assistance request (AAR) control subfield of the HT control field. For example, a reserved bit in the AAR control subfield may indicate whether the state of the link of the EMLSR non-AP MLD is changing. For ease of explanation, the reserved bit may be referred to as an EMLSR Link Update subfield. An Assisted AP Link ID Bitmap in the AAR control subfield may be reused to indicate a specific available link of the EMLSR non-AP MLD.

[0220] FIG. 9a is a schematic diagram of a frame format of the AAR control subfield according to an embodiment of the present application. As shown in FIG. 9a, the AAR control subfield includes, but is not limited to, a 16-bit Assisted AP Link ID Bitmap and a 1-bit EMLSR Link Update subfield. When the EMLSR Link Update subfield is set to 1 (i.e., the third indication information), it indicates that the status of the link of the non-AP MLD has changed. That is, the link may be unavailable or may become available and resume. When the EMLSR Link Update subfield is set to 0, it indicates that the status of the link has not changed. It should be understood that whether the EMLSR Link Update subfield is set to 0 to indicate that the status of the link has changed or is set to 1 to indicate that the status of the link has changed is not limited in this embodiment of the present application. When the EMLSR Link Update subfield is set to 1, the link corresponding to the bit set to 1 in the Assisted AP Link ID Bitmap (i.e., the fourth indication information) is an available link of the EMLSR non-AP MLD. It should be understood that if all bits in the Assisted AP Link ID Bitmap are 0, it indicates that all links in the EMLSR non-AP MLD are unavailable or there are no available links, i.e., the number of available links in the EMLSR non-AP MLD is 0 or the entire EMLSR non-AP MLD is unavailable.

[0221] In this embodiment of the present application, an indication that the status of the non-AP MLD link is changing (i.e., EMLSR Link Update subfield) is added to the AAR control subfield, and the Assisted AP Link ID Bitmap is reused, but the meaning of the Assisted AP Link ID Bitmap is modified to indicate the available link of the EMLSR non-AP MLD. No new frame format or procedure needs to be designed to reduce the signaling overhead.

[0222] Optionally, the third indication information and the fourth indication information can be placed in an aggregated-control (A-control) subfield. For example, an A-control subfield variant may be redesigned to carry the third indication information and the fourth indication information.

[0223] Figure 9b is a schematic diagram of a frame format of the A-control subfield according to an embodiment of the present application. As shown in Figure 9b, the A-control subfield includes, but is not limited to, a 16-bit EMLSR Link ID Bitmap and a 1-bit EMLSR Link Update subfield. For the value and meaning of the EMLSR Link Update subfield, please refer to the above description of Figure 9a. The details will not be described again in this specification. When the EMLSR Link Update subfield is set to 1, the link corresponding to the bit set to 1 (i.e., the fourth indication information) in the EMLSR Link ID Bitmap is the available link of the EMLSR non-AP MLD. It should be understood that if all the bits in the EMLSR Link ID Bitmap are 0, it indicates that there is no available link in the EMLSR non-AP MLD. That is, the number of available links in the EMLSR non-AP MLD is 0, or the entire EMLSR non-AP MLD is unavailable. It should be further understood that whether a bit having a value 0 in the EMLSR Link ID Bitmap represents an available link or a bit having a value 1 represents an available link is not limited in this embodiment of the present application.

[0224] In this embodiment of the present application, the new A-control subfield is designed to carry the third indication information and the fourth indication information. The meaning of the A-control subfield is clear, and the conventional station will not misread the A-control subfield (because the conventional station does not understand the newly designed A-control subfield).

[0225] Optionally, the third indication information and the fourth indication information can be placed in an EML control field of an EML operating mode notification (OMN) frame, and an EMLSR mode subfield included in the EML control field is set to 1. That is, the third frame is an EML OMN frame. For example, a reserved bit in the EML control subfield may indicate whether a state of a link of the EMLSR non-AP MLD is changing. For ease of explanation, the reserved bit may be referred to as an EMLSR Link Update subfield. An EMLSR link bitmap in the EML control subfield may be reused to indicate a specific available link of the EMLSR non-AP MLD.

[0226] In addition, optionally, the EML control field is extensible, so that the EMLSR non-AP MLD can further use the third frame to carry some related information, such as the start time of the state change and the specific capability of the EMLSR STA in the available state. In other words, the EML OMN frame carrying the third indication information and the fourth indication information (i.e., the third frame) may further include one or more of the information such as the start time of the link state change, the transmission and reception capability of the currently available link of the EMLSR non-AP MLD, etc.

[0227] Figure 9c is a schematic diagram of a frame format of an EML control field according to an embodiment of the present application. As shown in Figure 9c, the EML control field includes, but is not limited to, a 1-bit EMLSR mode subfield, a 16-bit EMLSR Link Bitmap, and a 1-bit EMLSR Link Update subfield. The EMLSR mode subfield is set to 1. For the value and meaning of the EMLSR Link Update subfield, please refer to the above description of Figure 9a. Details will not be described again in this specification. For the value and meaning of the EMLSR Link Bitmap, please refer to the related description of the EMLSR Link ID Bitmap in Figure 9b. Details will not be described again in this specification. As shown in Figure 9c, the EML control field may further include a starttime subfield and / or a supported EHT-MCS (Modulation and coding strategy) and NSS (Number of spatial streams) set subfield. The starttime subfield indicates the start time at which the link state changes. The Supported EHT-MCS and NSS Set subfield indicates the specific transmission and reception capabilities of the currently available link. The design of the Supported EHT-MCS and NSS Set subfield may be based on Section 9.4.2.313.1 of 802.11be D1.4, and therefore will not be described in detail herein.

[0228] In this embodiment of the present application, the EML control field of the EML OMN frame (i.e., the third frame) carries the third indication information and the fourth indication information. Because the EML control field is extensible, some optional information may be further carried. The implementation of the EML OMN frame is more flexible and more information can be carried.

[0229] It should be understood that the names, sequences, and lengths of the subfields shown in Figures 9a to 9c are examples, which are not limiting in this embodiment of the present application.

[0230] In an optional embodiment, the EMLSR non-AP MLD generates and transmits a third frame. The third frame includes third indication information, and the third indication information indicates whether the link status of the EMLSR non-AP MLD has changed. When the third indication information indicates that the link status of the EMLSR non-AP MLD has changed, the third frame further includes fourth indication information, and the fourth indication information indicates an available link of the EMLSR non-AP MLD. For the third indication information, please refer to the related description of the EMLSR Link Update subfield in the first implementation. For the fourth indication information, please refer to the related description of the first implementation. Details will not be described again in this specification.

[0231] Implementation form 2 If the state change of the link of the non-AP MLD is that the EMLSR link is disabled, the third indication information specifically indicates that the EMLSR link is disabled, or indicates that one or more EMLSR links will not be used by the non-AP MLD for the EMLSR mode and will not be a member of the EMLSR links. Correspondingly, the fourth indication information may indicate an available link of the EMLSR non-AP MLD or a disabled EMLSR link of the EMLSR non-AP MLD. If the state change of the link of the non-AP MLD is that an unavailable link in the EMLSR non-AP MLD is changing to an available EMLSR link, the third indication information specifically indicates that there is an unavailable link changing (or resuming) to an available EMLSR link in the EMLSR non-AP MLD, or indicates that there is an unavailable link returning to listening operation in the EMLSR non-AP MLD, or indicates that one or more EMLSR links should not be used by the non-AP MLD for the EMLSR mode and will not be a member of the EMLSR links. Correspondingly, the fourth indication information may indicate an available link of the EMLSR non-AP MLD, or an EMLSR link changing from unavailable to available in the EMLSR non-AP MLD.

[0232] For example, the fourth indication information may be a bitmap, and one bit of the fourth indication information corresponds to one link. When a bit in the fourth indication information is set to a first value, it indicates that the link corresponding to the bit is an available link or a link whose status has changed. When a bit in the fourth indication information is set to a second value, it indicates that the link corresponding to the bit is an unavailable link or a link whose status has not changed. The first value may be 1, and the second value may be 0, or the first value is 0 and the second value is 1. This is not limited in this embodiment of the present application. For example, the fourth indication information may also be represented by a link identifier (link ID).

[0233] Optionally, the third indication information may be represented by two subfields. One subfield indicates that the EMLSR link is disabled, and the other subfield indicates that the available EMLSR link in the EMLSR non-AP MLD has a changed unavailable link. In other words, the third indication information may specifically indicate that the EMLSR link is disabled, and that the available EMLSR link in the EMLSR non-AP MLD has no changed unavailable link. Alternatively, the third indication information may specifically indicate that the EMLSR link is not disabled, and that the available EMLSR link in the EMLSR non-AP MLD has a changed unavailable link. Alternatively, the third indication information may specifically indicate that the EMLSR link is disabled, and that the available EMLSR link in the EMLSR non-AP MLD has a changed unavailable link. In this case, the fourth indication information indicates the available link of the EMLSR non-AP MLD.

[0234] Optionally, the third indication information and the fourth indication information are placed in an AP assistance request (AAR) control subfield of the HT control field. In one implementation, the third indication information is represented by one subfield. Figure 10a is a schematic diagram of another frame format of the AAR control subfield according to one embodiment of the present application. As shown in Figure 10a, the AAR control subfield includes, but is not limited to, a 16-bit Assisted AP link ID bitmap subfield and a 1-bit EMLSR Link Disable / Resume subfield. When the EMLSR Link Disable / Resume subfield (i.e., the third indication information) is set to 1, it indicates that the EMLSR link is disabled. That is, there is an EMLSR link that enters an unavailable state. In this case, the link corresponding to the bit set to 1 in the Assisted AP link ID bitmap (i.e., the fourth indication information) is the disabled EMLSR link in the EMLSR non-AP MLD, and the link corresponding to the bit set to 0 is the available link in the EMLSR non-AP MLD. In other words, when the EMLSR Link Disable / Resume subfield is set to 1, it indicates that there is an EMLSR link that enters an unavailable state. In this case, the bit corresponding to the unavailable link in the Assisted AP link ID bitmap can be set to 1 for indication. Setting the bit to 0 is similar. When the EMLSR Link Disable / Resume subfield (i.e., the third indication information) is set to 0, it indicates that there is an unavailable link that is changing (or resuming) to an available EMLSR link in the EMLSR non-AP MLD, or that there is an unavailable link that returns to listening operation in the EMLSR non-AP MLD.In this case, the link corresponding to the bit set to 1 (i.e., the fourth indication information) in the Assisted AP link ID bitmap is the EMLSR link that has changed from unavailable to available in the EMLSR non-AP MLD, and the link corresponding to the bit set to 0 is the unavailable link in the EMLSR non-AP MLD. In other words, when the EMLSR Link Disable / Resume subfield is set to 0, it indicates that there is a link resuming from unavailable in the EMLSR non-AP MLD. In this case, the bit corresponding to the EMLSR link that has become available and resumes in the Assisted AP Link ID Bitmap may be set to 1 for indication. Setting the bit to 0 is similar.

[0235] In another implementation, the third indication information is represented by two subfields. Figure 10b is a schematic diagram of yet another frame format of the AAR control subfield according to an embodiment of the present application. As shown in Figure 10b, the AAR control subfield includes, but is not limited to, a 16-bit Assisted AP Link ID Bitmap, a 1-bit EMLSR Link Disable subfield, and a 1-bit EMLSR Link Resume subfield. When the EMLSR Link Disable subfield (i.e., one indication subinformation in the third indication information) is set to 1, it indicates that the EMLSR link is disabled. That is, there is an EMLSR link that enters an unavailable state. In this case, the link corresponding to the bit set to 1 in the Assisted AP link ID bitmap (i.e., the fourth indication information) is the disabled EMLSR link of the EMLSR non-AP MLD, and the link corresponding to the bit set to 0 is the available link of the EMLSR non-AP MLD. When the EMLSR Link Disable subfield is set to 0, it indicates that the subfield is reserved or that the EMLSR link is not disabled. When the EMLSR Link Resume subfield (i.e., another indication subfield in the third indication information) is set to 1, it indicates that there is an unavailable link changing (or resuming) to an available EMLSR link in the EMLSR non-AP MLD, or that there is an unavailable link returning to listening operation in the EMLSR non-AP MLD. In this case, the link corresponding to the bit set to 1 (i.e., the fourth indication information) in the Assisted AP link ID bitmap is the EMLSR link changing from unavailable to available in the EMLSR non-AP MLD, and the link corresponding to the bit set to 0 is the unavailable link in the EMLSR non-AP MLD.When the EMLSR Link Resume subfield is set to 0, this indicates that the subfield is reserved or that there are no unavailable links in the EMLSR non-AP MLD that will return to listening operation.

[0236] It should be understood that the names, sequences, and lengths of the subfields shown in Figures 10a and 10b are examples, which are not limiting in this embodiment of the present application.

[0237] Optionally, the third indication information and the fourth indication information are placed in an aggregated-control (A-control) subfield. For example, the A-control subfield variant may be redesigned to carry the third indication information and the fourth indication information, and the existing A-control subfield used to realize another function is not reused. In one implementation, the third indication information is represented by one subfield. Figure 11a is a schematic diagram of another frame format of the A-control subfield according to an embodiment of the present application. As shown in Figure 11a, the A-control subfield includes, but is not limited to, a 16-bit EMLSR Link Identifier Bitmap and a 1-bit EMLSR Link Disable / Resume subfield. For the value and meaning of the EMLSR Link ID Bitmap, please refer to the description of the Assisted AP link ID bitmap in Figure 10a or Figure 10b. Details will not be described again in this specification. For the values ​​and meanings of the EMLSR Link Disable / Resume subfield, please refer to the related description of Figure 10a. The details will not be described again in this specification.

[0238] In another implementation, the third indication information is represented by two subfields. Figure 11b is a schematic diagram of yet another frame format of the A-control subfield according to an embodiment of the present application. As shown in Figure 11b, the A-control subfield includes, but is not limited to, a 16-bit EMLSR Link ID Bitmap, a 1-bit EMLSR Link Disable subfield, and a 1-bit EMLSR Link Resume subfield. For the value and meaning of the EMLSR Link ID Bitmap, please refer to the description of the Assisted AP link ID bitmap in Figure 10a or Figure 10b. Details will not be described again in this specification. For the value and meaning of the EMLSR Link Disable subfield and the EMLSR Link Resume subfield, please refer to the related description of Figure 10b. Details will not be described again in this specification.

[0239] It should be understood that the names, sequences, and lengths of the subfields shown in Figures 11a and 11b are examples, which are not limiting in this embodiment of the present application.

[0240] Optionally, the third indication information and the fourth indication information are placed in an EML control field of an EML operating mode notification (OMN) frame, and the EMLSR mode subfield included in the EML control field is set to 1. That is, the third frame is an EML OMN frame. Since the EML control field is extensible, the EMLSR non-AP MLD may further use the third frame to carry some related information, such as the start time and end time of the unavailable state, and another specific capability of the EMLSR STA in the available state. In other words, the EML control field may further include one or more of the following information: disable start time, available start time, disable end time, disable duration, and transmission and reception capability of the available link of the EMLSR non-AP MLD.

[0241] In one implementation, the third indication information is represented by one subfield. Figure 12a is a schematic diagram of another frame format of the EML control field according to one embodiment of the present application. As shown in Figure 12a, the EML control field includes, but is not limited to, a 1-bit EMLSR mode subfield, a 16-bit EMLSR Link Bitmap, and a 1-bit EMLSR Link Disable / Resume subfield. The EMLSR mode subfield is set to 1. For the value and meaning of the EMLSR Link Disable / Resume subfield, please refer to the related description of Figure 10a. Details will not be described again in this specification. For the value and meaning of the EMLSR Link Bitmap, please refer to the description of the Assisted AP link ID bitmap in Figure 10a or Figure 10b. Details will not be described again in this specification. Optionally, when the EMLSR Link Disable / Resume subfield is set to 1 to indicate that there is an EMLSR link that enters an unavailable state, the EML control field shown in Fig. 12a may further include one or more of the following subfields: a Start Time subfield, an endtime subfield, a duration subfield, and a Supported EHT-MCS And NSS Set subfield. In this case, the Start Time subfield indicates the disable start time, the endtime subfield indicates the disable end time, the duration subfield indicates the disable duration, and the Supported EHT-MCS And NSS Set subfield indicates the specific transmission and reception capabilities of the currently available link. The design of the Supported EHT-MCS And NSS Set subfield may be based on Section 9.4.2.313.1 of 802.11be D1.4, and therefore will not be described in detail herein.When the EMLSR Link Disable / Resume subfield is set to 0 to indicate that there is an unavailable link changing (or resuming) to an available EMLSR link in the EMLSR non-AP MLD, the EML control field shown in FIG. 12a may further include a Start Time subfield indicating the availability start time, i.e., the time at which the unavailable link resumes to an available EMLSR link.

[0242] In another implementation, the third indication information is represented by two subfields. Figure 12b is a schematic diagram of yet another frame format of the EML control field according to an embodiment of the present application. As shown in Figure 12b, the EML control field includes, but is not limited to, a 1-bit EMLSR mode subfield, a 16-bit EMLSR Link Bitmap, a 1-bit EMLSR Link Disable subfield, and a 1-bit EMLSR Link Resume subfield. Optionally, the EML control field may further include one or more of a Start Time subfield, an end time subfield, a duration subfield, and a Supported EHT-MCS And NSS Set subfield. The EMLSR mode subfield is set to 1. For the values ​​and meanings of the EMLSR Link Disable subfield and the EMLSR Link Resume subfield, please refer to the related description of Figure 10b. Details will not be described again in this specification. For the value and meaning of the EMLSR Link Bitmap, please refer to the description of the Assisted AP link ID bitmap in Fig. 10a or Fig. 10b. The details will not be described again in this specification. For the Start Time subfield, the End Time subfield, the Duration subfield, and the Supported EHT-MCS And NSS Set subfield, please refer to the corresponding descriptions in Fig. 12a. The details will not be described again in this specification.

[0243] It should be understood that the names, sequences, and lengths of the subfields shown in Figures 12a and 12b are examples, which are not limiting in this embodiment of the present application.

[0244] The above describes in detail the procedure of the transmitting end in this embodiment of the present application. In some other embodiments of the present application, corresponding to the procedure of the transmitting end (steps S201 and S202), the link status indication method of the receiving end in EMLSR mode includes, but is not limited to, the following steps:

[0245] S203: The AP MLD receives a third frame. The third frame includes fourth indication information. Optionally, the third frame further includes third indication information. The third indication information indicates that the state of the link of the non-AP MLD is changing. The fourth indication information indicates the available link or the link whose state is changing in the EMLSR non-AP MLD. Specifically, for the implementation of the third indication information and the fourth indication information, please refer to the above description. Details will not be described again in this specification.

[0246] S204: The AP MLD determines an available link of the EMLSR non-AP MLD according to the fourth indication information in the third frame.

[0247] Optionally, after receiving the third frame, the AP MLD associated with the EMLSR non-AP MLD determines an available link of the EMLSR non-AP MLD based on the third indication information and the fourth indication information carried in the third frame. When the AP (or AP MLD) side receives a notification indicating that the EMLSR non-AP MLD (or some of its links) enters an unavailable state, the AP side does not send an initial control frame to the EMLSR non-AP MLD on the unavailable link until the AP side receives a notification indicating that the unavailable link becomes available and resumes.

[0248] After the EMLSR non-AP MLD sends a notification indicating that an unavailable link has become available and resumed, the EMLSR STAs on the available and resumed link may switch to listening mode immediately or switch to listening mode after a specified time T (e.g., short interframe space (SIFS)). If the available and resumed link in the EMLSR non-AP MLD is a reception-limited link, the AP (or AP MLD) receiving the notification needs to wait at least one transition delay (the specific waiting duration may be the transition delay + the specified time T) before sending an initial control frame to the available and resumed EMLSR STA. If the available and resumed link in the EMLSR non-AP MLD is a reception-full-capability link, the AP (or AP MLD) receiving the notification may directly send an initial control frame to the available and resumed EMLSR STA without waiting, or may send an initial control frame to the available and resumed EMLSR STA after the specified time T.

[0249] Optionally, when the antenna capability configuration of the EMLSR non-AP MLD is asymmetric, when the receiving full capability link of the EMLSR non-AP MLD is available, the AP MLD may send an MU-RTS frame or a BSRP frame to the EMLSR non-AP MLD on the receiving full capability link, and use the MU-RTS frame or the BSRP frame to carry indication information indicating whether the MU-RTS frame or the BSRP frame is an initial control frame, or whether the MU-RTS frame or the BSRP frame received by the station is an initial control frame. Specifically, for possible implementation forms of the indication information, please refer to the following description of embodiment 4 and embodiment 5. Details will not be described in this specification.

[0250] In this embodiment of the present application, when the EMLSR non-AP MLD or the EMLSR STA on the link of the EMLSR non-AP MLD is temporarily unavailable for some reason, the EMLSR non-AP MLD actively reports the status change of the link of the EMLSR non-AP MLD and reports the changed link, so that the AP MLD knows the status change of the link of the EMLSR non-AP MLD associated with the AP MLD and the changed link in a timely manner. Therefore, the AP MLD does not send an initial control frame to the EMLSR non-AP MLD on the unavailable link of the EMLSR non-AP MLD to reduce resource waste.

[0251] EMBODIMENT 3 This embodiment of the present application mainly describes that when the EMLSR non-AP MLD or an EMLSR STA on the EMLSR non-AP MLD link is temporarily unavailable for some reason, or when the EMLSR STA ends the unavailability and is ready to resume listening mode, the AP MLD associated with the EMLSR non-AP MLD is implicitly notified of the status change of the EMLSR non-AP MLD link.

[0252] 13 is a third schematic flowchart of a link status indication method in EMLSR mode according to an embodiment of the present application. In this embodiment of the present application, the antenna capability configuration of EMLSR non-AP MLD can be symmetric or asymmetric. This is not limited in this embodiment of the present application. As shown in FIG. 13, the link status indication method in EMLSR mode includes, but is not limited to, the following steps:

[0253] S301: After the EMLSR non-AP MLD and the associated AP MLD enter the EMLSR mode by exchanging EML OMN frames, the EMLSR non-AP MLD generates a first EML OMN frame, the first EML OMN frame includes an EMLSR mode subfield and an EMLSR link bitmap, the EMLSR mode subfield is set to 1, and the first EML OMN frame is used to notify the updated EMLSR link.

[0254] S302: The EMLSR non-AP MLD sends a first EML OMN frame to the AP MLD.

[0255] Optionally, after the EMLSR non-AP MLD and the associated AP MLD enter the EMLSR mode by exchanging EML OMN frames (in this case, both EMLSR mode subfields in the two exchanged EML OMN frames are set to 1), the EMLSR non-AP MLD may generate another EML OMN frame (for ease of distinction, the generated EML OMN frame is called the first EML OMN frame). The EMLSR non-AP MLD may transmit the first EML OMN frame to the AP MLD on any available link. The first EML OMN frame is used to notify the updated EMLSR link. For the frame format of the first EML OMN frame, please refer to the description of the EML OMN frame in the existing standard. Details will not be described in this specification. In other words, in this embodiment of the present application, the function of the EML OMN frame is added, and the frame format of the EML OMN frame is not changed. The first EML OMN frame includes an EMLSR Mode subfield and an EMLSR Link Bitmap, where the EMLSR Mode subfield is set to 1. The EMLSR Link Bitmap subfield indicates the subset of the enabled links that is used by the non-AP MLD in the EMLSR mode. For more information, please refer to the description in the existing standard. The links corresponding to the bits with value 1 in the EMLSR Link ID Bitmap are used by the non-AP MLD in the EMLSR mode and have either changed to elements of EMLSR links or returned to listening mode. In other words, the links corresponding to the bits with value 1 in the EMLSR Link Bitmap are the currently available links.

[0256] Optionally, the EML control field of the first EML OMN frame may further include one or more of the following information: the start time of the EMLSR link update, and the transmission and reception capabilities of the available links of the EMLSR non-AP MLD. For example, a start time subfield may be newly added to the EML control field to indicate the start time of the EMLSR link update, and a Supported EHT-MCS And NSS Set subfield may be added to indicate the specific transmission and reception capabilities of the currently available links. The design of the Supported EHT-MCS And NSS Set subfield may be based on Section 9.4.2.313.1 of 802.11be D1.4, and therefore will not be described in detail herein.

[0257] S303: The AP MLD receives a first EML OMN frame.

[0258] S304: The AP MLD determines an available link of the EMLSR non-AP MLD based on the first EML OMN frame.

[0259] Optionally, after the EMLSR non-AP MLD and the associated AP MLD enter the EMLSR mode by exchanging EML OMN frames (in this case, both EMLSR mode subfields in the two exchanged EML OMN frames are set to 1), the AP MLD receives a new EML OMN frame (i.e., the first EML OMN frame) sent by the EMLSR non-AP MLD, and the EMLSR mode subfield is still 1. This indicates that the EMLSR non-AP MLD is not ready to exit the EMLSR mode at this point. Therefore, the AP MLD may understand the new EML OMN frame (i.e., the first EML OMN frame) with the EMLSR mode subfield set to 1 as a notification of a state change of the EMLSR link. Then, the AP MLD may determine the available links of the EMLSR non-AP MLD, i.e., the links corresponding to the bits in the EMLSR Link Bitmap whose values ​​are 1, based on the indication of the EMLSR Link Bitmap in the first EML OMN frame.

[0260] In this embodiment of the present application, no new field (or subfield) needs to be added to indicate the link status change of the EMLSR non-AP MLD, but the function and specific rules of the EML OMN frame are added to notify the link status change. In this way, the AP MLD can timely know the currently available links of the EMLSR non-AP MLD associated with the AP MLD, and the AP MLD will not send an initial control frame on the unavailable links of the EMLSR non-AP MLD to reduce resource waste.

[0261] EMLSR non-AP MLD may have links with asymmetric antenna capability configurations. That is, each link has one antenna, where the antenna has a stronger receiving capability and can receive all types of PPDUs, and another antenna has a weaker receiving capability and can only receive some types of PPDUs. Thus, the AP may be able to communicate normally with the EMLSR STA with the stronger antenna receiving capability and not need to use the antenna on the other link. In this way, the AP may not need to send an initial control frame before sending downlink data to the EMLSR STA with the stronger antenna receiving capability. Thus, when the EMLSR STA receives a MU-RTS frame or a BSRP frame, the EMLSR STA cannot determine whether the received frame is an initial control frame or not. That is, EMLSR non-AP MLD cannot determine whether the antenna / spatial stream on the other link needs to be temporarily switched to the link on which the EMLSR STA operates. It will be appreciated that the AP may normally communicate with the EMLSR STA with the stronger antenna receiving capability without using the antenna on the other link, but the EMLSR STA may need to use multi-spatial stream transmission. Therefore, even if the EMLSR STA has a stronger receiving capability, there is only one antenna on the link on which the EMLSR STA operates, and multiple spatial streams cannot be realized. Therefore, the antenna / spatial stream on another link may need to be temporarily switched to the link on which the EMLSR STA operates.

[0262] In order to solve the problem that when the antenna capability configuration of EMLSR non-AP MLD is asymmetric, the STA on the receiving full-capability link cannot determine whether the received MU-RTS frame or BSRP frame is an initial control frame, the present application further provides a frame type indication method in EMLSR mode, to indicate whether the MU-RTS frame or BSRP frame is an initial control frame by adding indication information to the MU-RTS frame or BSRP frame. In this way, the EMLSR STA on the receiving full-capability link can determine whether the received MU-RTS frame or BSRP frame is an initial control frame, and determine the behavior of the EMLSR STA after receiving the MU-RTS frame or BSRP frame.

[0263] The frame type indication method in EMLSR mode provided in this application is described in detail below.

[0264] EMBODIMENT 4 This embodiment of the present application mainly describes how a STA on a receiving full-capability link determines whether a received MU-RTS frame or BSRP frame is an initial control frame when the antenna capability configuration of EMLSR non-AP MLD is asymmetric.

[0265] Optionally, the fourth embodiment of the present application may be implemented together with any one of the first to third embodiments, or may be implemented separately, which is not limited in the present application.

[0266] Figure 14 is a schematic flowchart of a frame type indication method in EMLSR mode according to an embodiment of the present application. In this embodiment of the present application, the antenna capability configuration of EMLSR non-AP MLD is asymmetric. That is, each link of EMLSR non-AP MLD has one antenna, one antenna is a common antenna, and the other antenna is a limited antenna. The link where the common antenna is configured is called a RX full capability link, and the link where the limited antenna is configured is called a RX limitation link. As shown in Figure 14, the frame type indication method in EMLSR mode includes, but is not limited to, the following steps:

[0267] S401: AP MLD generates a control frame, the control frame includes a first user information field, the first user information field includes an association identifier 12 subfield and indication information, and the indication information indicates whether the control frame received by the station indicated by the association identifier 12 subfield is an initial control frame.

[0268] S402: The AP MLD transmits a control frame.

[0269] S403: EMLSR non-AP MLD receives a control frame.

[0270] S404: The EMLSR non-AP MLD determines whether the received control frame is an initial control frame.

[0271] The control frame is an MU-RTS frame or a BSRP frame.

[0272] There are a plurality of links between the EMLSR non-AP MLD and the AP MLD, and the plurality of links includes at least one full-capability receiving link and at least one restricted-receiving link.

[0273] Optionally, the AP MLD may generate and transmit an MU-RTS frame or a BSRP frame. In response, the EMLSR non-AP MLD receives a control frame. The MU-RTS frame or the BSRP frame includes one or more user information fields. In one implementation, the indication information is carried in each user information field. In another implementation, the indication information is carried only in the user information field corresponding to the EMLSR station. The first user information field (which is each user information field or the user information field corresponding to the EMLSR station) includes an association identifier (AID) 12 subfield and indication information. The AID 12 subfield indicates the station. The indication information may indicate whether the control frame (i.e., the MU-RTS frame or the BSRP frame) received by the station indicated by the AID 12 subfield is an initial control frame. The EMLSR station is a station that enters the EMLSR mode in the EMLSR non-AP MLD.

[0274] Optionally, the length of the indication information may be 1 bit. When the indication information is set to a first value, it indicates that the control frame (i.e., MU-RTS frame or BSRP frame) received by the station indicated by the AID12 subfield is an initial control frame. When the indication information is set to a second value, it indicates that the control frame (i.e., MU-RTS frame or BSRP frame) received by the station indicated by the AID12 subfield is not an initial control frame. The first value is 1 and the second value is 0, or the first value is 0 and the second value is 1. This is not limited in this embodiment of the present application.

[0275] For example, the indication information may be represented by one reserved bit in the user info field. For ease of explanation, the indication information may be referred to as an EMLSR Initial Control subfield. Figure 15 is a schematic diagram of a frame format of a user information field in a MU-RTS frame or a BSRP frame according to one embodiment of the present application. As shown in Figure 15, the user information field in a MU-RTS frame or a BSRP frame includes, but is not limited to, an AID12 subfield and a 1-bit EMLSR Initial Control subfield.

[0276] When the EMLSR Initial Control subfield is set to 0, it indicates that the current MU-RTS or BSRP frame is a common control frame of the STA indicated by the AID12 subfield, or the MU-RTS or BSRP frame received by the station indicated by the AID12 subfield is not an initial control frame. It should be understood that if the STA receiving the current MU-RTS or BSRP frame and whose AID is the same as the AID12 subfield is an EMLSR STA (EMLSR STA in this specification is a STA on a receiving full-capability link), the EMLSR STA does not need to enter EMLSR mode. That is, the EMLSR non-AP MLD does not need to switch the antenna / spatial stream on another (specified) link to the link for receiving the initial control frame, and needs to respond with a corresponding response frame.

[0277] When the EMLSR Initial Control subfield is set to 1, it indicates that the current MU-RTS or BSRP frame is the initial control frame of the STA indicated by the AID 12 subfield, or the MU-RTS or BSRP frame received by the station indicated by the AID 12 subfield is the initial control frame. Therefore, an EMLSR STA that receives an MU-RTS or BSRP frame and whose AID is the same as the AID 12 subfield must enter EMLSR mode. That is, the EMLSR non-AP MLD switches the antenna / spatial stream on another (specified) link to the link for receiving the initial control frame in preparation for transmitting and receiving data.

[0278] It should be understood that the names, sequence, and lengths of the subfields shown in Figure 15 are examples, which are not limiting in this embodiment of the present application.

[0279] It should be further understood that in this embodiment of the present application, the indication information (i.e., the EMLSR Initial Control subfield) is placed in the User Information field of the MU-RTS frame or the BSRP frame. Thus, the MU-RTS frame or the BSRP frame may trigger multiple EMLSR STAs and non-EMLSR STAs simultaneously. Thus, if the STA corresponding to the AID12 subfield is an EMLSR STA, the reserved bit in the User Info field may be changed to the EMLSR Initial Control subfield. If the STA corresponding to the AID12 subfield is a non-EMLSR STA, the reserved bit in the User Information field of the AID12 subfield may also be changed to the EMLSR Initial Control subfield, and the value of the EMLSR Initial Control subfield is set to 0 to indicate that the current MU-RTS frame or the BSRP frame is a common control frame (corresponding to an implementation in which each User Information field carries indication information). Alternatively, if the STA corresponding to the AID12 subfield is an EMLSR STA, the reserved bit in the User Info field of the AID12 subfield may be changed to the EMLSR Initial Control subfield. If the STA corresponding to the AID12 subfield is a non-EMLSR STA, the reserved bit in the User Info subfield may not be changed (corresponding to an implementation in which the User Information field corresponding to the EMLSR station carries indication information).

[0280] Optionally, in this embodiment of the present application, the AP MLD may be allowed to transmit the MU-RTS frame or BSRP frame carrying the indication information (or the EMLSR Initial Control subfield) only on the receiving full-capability link. Of course, in this embodiment of the present application, the AP MLD may also be allowed to transmit the MU-RTS frame or BSRP frame carrying the indication information (or the EMLSR Initial Control subfield) on both the receiving full-capability link and the receiving restricted link, but the indication information in the MU-RTS frame or BSRP frame transmitted on the receiving restricted link is set to a first value to indicate that the MU-RTS frame or BSRP frame received by the station on the receiving restricted link is an initial control frame. This is because the station on the receiving restricted link can only receive the initial control frame.

[0281] Optionally, after receiving the MU-RTS or BSRP frame, the EMLSR non-AP MLD determines whether the MU-RTS or BSRP frame received by the EMLSR non-AP MLD is an initial control frame based on the indication information carried in the user information field. If the EMLSR non-AP MLD determines that the MU-RTS or BSRP frame received by the EMLSR non-AP MLD is an initial control frame, the EMLSR non-AP MLD may switch the antenna / spatial stream on another (designated) link to the link for receiving the initial control frame in preparation for transmitting and receiving data. If the EMLSR non-AP MLD determines that the MU-RTS or BSRP frame received by the EMLSR non-AP MLD is not an initial control frame, the EMLSR non-AP MLD may respond with a response frame of the MU-RTS or BSRP frame.

[0282] In this embodiment of the present application, when the antenna capability configuration of the EMLSR non-AP MLD is asymmetric, the indication information is carried in the user information field of the MU-RTS frame or the BSRP frame to indicate whether the MU-RTS frame or the BSRP frame received by the station is an initial control frame. In this way, the EMLSR STA on the receiving full capability link of the EMLSR non-AP MLD can determine whether the received MU-RTS frame or the BSRP frame is an initial control frame to determine the subsequent behavior of the EMLSR STA. In addition, since the indication information is carried in the user information field, different information can be indicated for different stations. This implementation is more flexible. For example, the indication information is carried in the user information field, so that the same MU-RTS frame or the BSRP frame is the initial control frame of some EMLSR STAs and the common control frame of other EMLSR STAs.

[0283] EMBODIMENT 5 This embodiment of the present application mainly describes that when the antenna capability configuration of EMLSR non-AP MLD is asymmetric, indication information is carried in the common information field of the MU-RTS frame or BSRP frame, so that the STA on the receiving full capability link determines whether the received MU-RTS frame or BSRP frame is an initial control frame.

[0284] Optionally, the fifth embodiment of the present application may be implemented together with any one of the first to third embodiments, or may be implemented separately, which is not limited in the present application.

[0285] Figure 16 is another schematic flowchart of a frame type indication method in EMLSR mode according to an embodiment of the present application. In this embodiment of the present application, the antenna capability configuration of EMLSR non-AP MLD is asymmetric. That is, each link of EMLSR non-AP MLD has one antenna, one antenna is a common antenna, and the other antenna is a limited antenna. The link where the common antenna is configured is called RX full capability link, and the link where the limited antenna is configured is called RX limitation link. As shown in Figure 16, the frame type indication method in EMLSR mode includes, but is not limited to, the following steps:

[0286] S501: AP MLD generates a control frame, the control frame includes a common information field, the common information field includes indication information, and the indication information indicates whether the control frame is an initial control frame.

[0287] S502: The AP MLD transmits a control frame.

[0288] S503: EMLSR non-AP MLD receives a control frame.

[0289] S504: The EMLSR non-AP MLD determines whether the received control frame is an initial control frame.

[0290] The control frame is an MU-RTS frame or a BSRP frame.

[0291] There are a plurality of links between the EMLSR non-AP MLD and the AP MLD, and the plurality of links includes at least one full-capability receiving link and at least one restricted-receiving link.

[0292] Optionally, the AP MLD may generate and transmit an MU-RTS frame or a BSRP frame. The MU-RTS frame or the BSRP frame may include a common information field, which includes an indication information indicating whether the MU-RTS frame or the BSRP frame is an initial control frame. Correspondingly, the EMLSR non-AP MLD receives the MU-RTS frame or the BSRP frame, and determines whether the MU-RTS frame or the BSRP frame received by the EMLSR non-AP MLD is an initial control frame based on the indication of the common information field. If the EMLSR non-AP MLD determines that the MU-RTS frame or the BSRP frame received by the EMLSR non-AP MLD is an initial control frame, the EMLSR non-AP MLD may switch the antenna / spatial stream on another (designated) link to the link for receiving the initial control frame in preparation for transmitting and receiving data. If the EMLSR non-AP MLD determines that the MU-RTS or BSRP frame received by the EMLSR non-AP MLD is not an initial control frame, the EMLSR non-AP MLD may respond with a response frame for the MU-RTS or BSRP frame.

[0293] Optionally, the length of the indication information may be 1 bit. When the indication information is set to a first value, it indicates that the control frame (i.e., MU-RTS frame or BSRP frame) is an initial control frame. When the indication information is set to a second value, it indicates that the control frame (i.e., MU-RTS frame or BSRP frame) is not an initial control frame. The first value is 1 and the second value is 0, or the first value is 0 and the second value is 1. This is not limited in this embodiment of the present application.

[0294] For example, the indication information may be represented by one reserved bit in the Common Info field. For ease of explanation, the indication information may be referred to as the EMLSR Initial Control subfield. Figure 17 is a schematic diagram of a frame format of a common information field in a MU-RTS frame or a BSRP frame according to an embodiment of the present application. As shown in Figure 17, the common information field in a MU-RTS frame or a BSRP frame includes, but is not limited to, a 1-bit EMLSR Initial Control subfield. When the EMLSR Initial Control subfield is set to 0, it indicates that the current MU-RTS frame or BSRP frame is a common control frame, and the EMLSR STAs receiving the MU-RTS frame or BSRP frame do not need to enter EMLSR mode, and only need to respond with a corresponding response frame. When the EMLSR Initial Control subfield is set to 1, it indicates that the current MU-RTS frame or BSRP frame is an initial control frame, and the EMLSR STAs receiving the MU-RTS frame or BSRP frame need to enter EMLSR mode. That is, the EMLSR non-AP MLD switches the antenna / spatial stream on another (designated) link to the link for receiving the initial control frame in preparation for transmitting and receiving data.

[0295] It should be understood that the names, sequence, and lengths of the subfields shown in Figure 17 are examples, which are not limiting in this embodiment of the present application.

[0296] It should be further understood that in this embodiment of the present application, the indication information (i.e., EMLSR Initial Control subfield) is placed in the Common Info field of the MU-RTS frame or BSRP frame. Therefore, each STA that receives the MU-RTS frame or BSRP frame can read the indication information (i.e., EMLSR Initial Control subfield). Therefore, the indication information (i.e., EMLSR Initial Control subfield) indicates whether the MU-RTS frame or BSRP frame currently received by each STA is an initial control frame. If the STA that receives the MU-RTS frame or BSRP frame is a non-EMLSR STA, the EMLSR Initial Control subfield may be ignored. If the STA that receives the MU-RTS frame or BSRP frame is an EMLSR STA, a corresponding response is made based on the value of the EMLSR Initial Control subfield.

[0297] In this embodiment of the present application, the indication information is carried in the common information field of the MU-RTS frame or the BSRP frame to indicate whether the MU-RTS frame or the BSRP frame is an initial control frame. The problem that the STA on the receiving full-capability link cannot determine whether the received MU-RTS frame or the BSRP frame is an initial control frame of the EMLSR mode with asymmetric antenna configuration can be solved, so that the EMLSR non-AP MLD can determine the behavior of the EMLSR non-AP MLD after receiving the MU-RTS frame or the BSRP frame.

[0298] In addition, in some cases, the two links of non-AP MLD cannot transmit and receive at the same time. That is, when a STA on a link is transmitting, a STA on another link cannot meet the EHT reception requirements. Therefore, the nonsimultaneous transmit and receive (NSTR) capability is introduced. The possible cause in this case is that the spectrum space between the two links is too short, so that when a STA on one link transmits, the reception interference of the STA on the other link is too large. Therefore, when the two links of non-AP MLD have NSTR capability, both the non-AP MLD and the AP MLD associated with the non-AP MLD need to ensure that the transmission time of the STA on one link does not overlap with the reception time of the STA on the other link. However, in the case of an AP MLD associated with a non-AP MLD, STAs on some links with NSTR capability of the non-AP MLD may be unavailable for some reasons (including but not limited to point-to-point transmission (P2P), i.e., the STA communicates on the link with devices other than the AP MLD associated with the STA). Thus, when STAs on some links with NSTR capability of the non-AP MLD are unavailable for some reasons, normal communication will be affected if the associated AP MLD still initiates transmission to the STA.

[0299] The link state indication method provided in this embodiment of the present application can also solve the above-mentioned problems, for details, please refer to embodiment 6.

[0300] EMBODIMENT 6 This embodiment of the present application mainly describes how a non-AP MLD notifies an AP MLD associated with the non-AP MLD when the link pair of the non-AP MLD has NSTR capability, i.e., an NSTR link pair, and a STA on the NSTR link pair is temporarily unavailable or has ceased to be unavailable for some reason.

[0301] An NSTR link pair means that for two links in an MLD, when a STA on one link of the MLD is transmitting and a STA on the other link of the MLD cannot meet the EHT reception requirements, the two links form an NSTR link pair.

[0302] For example, a STA (STA1) on a non-AP MLD NSTR link pair may establish a P2P connection, such as a Tunneled Direct-link Setup (TDLS), to another non-AP MLD STA or a non-AP STA (STA3). In this case, when STA1 initiates a transmission to STA3, the AP MLD associated with the non-AP MLD is unaware of this transmission. Thus, when STA1 performs a P2P transmission to STA3, the associated AP MLD may simultaneously initiate a transmission to another STA (STA2) on the NSTR link pair. In this case, due to the NSTR feature, STA2 cannot successfully receive data transmitted by the AP MLD. In other words, when a STA on a non-AP MLD NSTR link pair transmits to a device other than the associated AP MLD, all STAs on the non-AP MLD NSTR link pair cannot successfully receive data transmitted from the associated AP MLD. That is, all STAs on the NSTR link pair are unavailable. However, according to existing standards and technologies, the AP MLD does not know whether an unavailability has occurred on the NSTR link pair of the non-AP MLD currently associated with the AP MLD. In this case, if the AP MLD continues to transmit data to the STA on the NSTR link pair of the non-AP MLD when the unavailability occurs, the STA cannot correctly receive or respond to the AP MLD. If the AP MLD does not receive a correct response, the AP MLD may repeatedly transmit the corresponding frame. This causes a waste of resources.

[0303] 20 shows a link state indication method provided in the present application. Specifically, the link (hereinafter, abbreviated as link) state indication method in an NSTR link pair includes, but is not limited to, the following steps:

[0304] S601: The non-AP MLD generates a third frame, where the third frame includes fourth indication information, and the fourth indication information indicates an available link or a link whose status is changing in the non-AP MLD.

[0305] S602: The non-AP MLD transmits a third frame.

[0306] Optionally, when the non-AP MLD determines that the status of all or some of the links of the non-AP MLD has changed, e.g., in the case of an AP MLD associated with the non-AP MLD, at least one link (of a station) of the non-AP MLD is unavailable or resumes from unavailable to available, the non-AP MLD may generate a third frame. The third frame may carry fourth indication information, and the fourth indication information may indicate the available links or the links whose status has changed in the non-AP MLD. Optionally, the third frame may further carry third indication information, and the third indication information may indicate whether the status of the links of the non-AP MLD has changed.

[0307] The non-AP MLD may transmit the third frame on any available link. Optionally, the state of the non-AP MLD link changes only after the non-AP MLD transmits the third frame or a certain period of time after the non-AP MLD transmits the third frame. Alternatively, the state of the non-AP MLD link may change only before the non-AP MLD transmits the third frame or a certain period of time before the non-AP MLD transmits the third frame.

[0308] Optionally, the state change of the non-AP MLD link includes, but is not limited to, the link being disabled and the non-AP MLD unavailable NSTR link being changed to an available link.

[0309] In order to better understand the indication manner of the third indication information and the fourth indication information, the following uses an example to describe possible implementation forms of the third indication information and the fourth indication information.

[0310] Implementation form 1 The third indication information may indicate that the state of the link of the non-AP MLD has changed, and the fourth indication information may indicate the available link of the non-AP MLD. For example, the fourth indication information may indicate the available link of the non-AP MLD using a bitmap. That is, one bit in the bitmap corresponds to one link. When a bit in the bitmap is set to 1, it indicates that the link corresponding to the bit is an available link. Alternatively, the fourth indication information may indicate the available link of the non-AP MLD using a link identifier (link ID). That is, the link identified by the link identifier is an available link. This is not limited in this embodiment of the present application.

[0311] Optionally, the third indication information and the fourth indication information can be placed in an AP assistance request (AAR) control subfield of the HT control field. For example, a reserved bit in the AAR control subfield may indicate whether the state of the link of the non-AP MLD is changing. For ease of explanation, the reserved bit may be referred to as a Link Update subfield. An Assisted AP Link ID Bitmap in the AAR control subfield may be reused to indicate a specific available link of the non-AP MLD.

[0312] FIG. 21a is a schematic diagram of a frame format of the AAR Control subfield according to an embodiment of the present application. As shown in FIG. 21a, the AAR Control subfield includes, but is not limited to, an Assisted AP Link ID Bitmap and a Link Update subfield. The Assisted AP Link ID Bitmap may be 16 bits, and the Link Update subfield may be 1 bit. When the Link Update subfield is set to 1 (i.e., the third indication information), it indicates that the link status of the non-AP MLD has changed. That is, the link may be unavailable or may become available and resume. When the Link Update subfield is set to 0, it indicates that the link status has not changed. It should be understood that whether the Link Update subfield is set to 0 to indicate that the link status has changed, or is set to 1 to indicate that the link status has changed, is not limited in this embodiment of the present application. When the Link Update subfield is set to 1, the link corresponding to the bit set to 1 (i.e., the fourth indication information) in the Assisted AP Link ID Bitmap is an available link of the non-AP MLD. It should be understood that if all bits in the Assisted AP Link ID Bitmap are 0, it indicates that all links in the non-AP MLD are unavailable or there are no available links, i.e., the number of available links in the non-AP MLD is 0 or the entire non-AP MLD is unavailable.

[0313] In this embodiment of the present application, an indication that the status of the non-AP MLD link is changing (i.e., Link Update subfield) is added to the AAR control subfield, and the Assisted AP Link ID Bitmap is reused, but the meaning of the Assisted AP Link ID Bitmap is modified to indicate the available link of the non-AP MLD. No new frame format or procedure needs to be designed to reduce the signaling overhead.

[0314] Optionally, the third indication information and the fourth indication information can be placed in an aggregated-control (A-control) subfield. For example, an A-control subfield variant may be redesigned to carry the third indication information and the fourth indication information.

[0315] FIG. 21b is a schematic diagram of a frame format of the A-control subfield according to an embodiment of the present application. As shown in FIG. 9b, the A-control subfield includes, but is not limited to, a Link ID Bitmap and a Link Update subfield. The Link ID Bitmap may be 16 bits, and the Link Update subfield may be 1 bit. For the value and meaning of the Link Update subfield, please refer to the description of FIG. 9a. The details will not be described again in this specification. When the Link Update subfield is set to 1, the link corresponding to the bit set to 1 (i.e., the fourth indication information) in the Link ID Bitmap is an available link of the non-AP MLD. It should be understood that if all the bits in the Link ID Bitmap are 0, it indicates that there is no available link in the non-AP MLD. That is, the number of available links of the non-AP MLD is 0, or the entire non-AP MLD is unavailable. It should be further understood that whether the bit with the value 0 in the Link ID Bitmap represents an available link, or the bit with the value 1 represents an available link, is not limited in this embodiment of the present application.

[0316] In this embodiment of the present application, the new A-control subfield is designed to carry the third indication information and the fourth indication information. The meaning of the A-control subfield is clear, and the conventional station will not misread the A-control subfield (because the conventional station does not understand the newly designed A-control subfield).

[0317] The above describes in detail the procedure of the transmitting end in this embodiment of the present application. In some other embodiments of the present application, corresponding to the procedure of the transmitting end (steps S601 and S602), the link status indication method of the receiving end includes, but is not limited to, the following steps:

[0318] S603: AP MLD receives a third frame. The third frame includes fourth indication information, and the fourth indication information indicates an available link or a link whose status has changed in non-AP MLD. Optionally, when the third frame further includes third indication information, the third indication information indicates whether the status of the link of non-AP MLD has changed. Specifically, for the implementation form of the third indication information and the fourth indication information, please refer to the above description. Details will not be described again in this specification.

[0319] S604: The AP MLD determines an available link of the non-AP MLD based on the fourth indication information in the third frame.

[0320] Optionally, after receiving the third frame, the AP MLD associated with the non-AP MLD determines the available link of the non-AP MLD based on the third indication information and the fourth indication information carried in the third frame. Specifically, the AP MLD may first obtain whether the state of the link of the non-AP MLD has changed based on the third indication information, and then refer to the fourth indication information to obtain the available link or the link whose state has changed in the non-AP MLD. When the AP (or AP MLD) side receives a notification indicating that the non-AP MLD (or some of its links) has entered an unavailable state, the AP side does not send an initial control frame to the non-AP MLD on the unavailable link until the AP side receives a notification indicating that the unavailable link becomes available and resumes.

[0321] After non-AP MLD sends a notification that an unavailable link has become available and resumed, STAs on the available link may immediately resume to their normal transmission / reception state or may wait a specified time T (e.g., a short interframe space (SIFS)) and then resume to their normal transmission / reception state.

[0322] In this embodiment of the present application, when the non-AP MLD or a STA on the link of the non-AP MLD is temporarily unavailable for some reason, the non-AP MLD actively reports the status change of the link of the non-AP MLD and reports the changed link, so that the AP MLD knows the status change of the link of the non-AP MLD associated with the AP MLD and the changed link in a timely manner. Therefore, the AP MLD does not start transmission to the non-AP MLD on the unavailable link of the non-AP MLD to reduce resource waste.

[0323] The foregoing describes in detail the method provided in the present application. To facilitate the implementation of the foregoing solutions of the implementation forms of the present application, the embodiments of the present application further provide a corresponding apparatus or device.

[0324] In the embodiment of the present application, the AP MLD and the non-AP MLD may be divided into functional modules based on the above-mentioned method example. For example, each functional module may be obtained by division based on each function, or two or more functions may be integrated into one processing module. The integrated module may be implemented in the form of hardware, or may be implemented in the form of a software functional module. It should be noted that in the embodiment of the present application, the division of modules is an example, and is merely a division of logical functions. In the actual implementation, another division method may be used. Hereinafter, the communication device in the embodiment of the present application will be described in detail with reference to FIG. 18 and FIG. 19. The communication device is an AP MLD or a non-AP MLD. Furthermore, the communication device may be a device in the AP MLD, or the communication device is a device in the non-AP MLD.

[0325] When an integrated unit is used, please refer to Figure 18. Figure 18 is a schematic diagram of the structure of a communication device according to an embodiment of the present application. As shown in Figure 18, the communication device includes a processing unit 11 and a transceiver unit 12.

[0326] In some embodiments of the present application, the communication device may be a non-AP MLD or a chip in the non-AP MLD, for example, a Wi-Fi chip, that is, the communication device may be configured to implement the steps or functions performed by the non-AP MLD in the embodiments of the above-mentioned method.

[0327] In a first design, the processing unit 11 is configured to generate a first frame, the first frame including first indication information, the first indication information indicating that the EMLSR non-AP MLD is disabled for the AP MLD, and the transceiver unit 12 is configured to transmit the first frame.

[0328] Optionally, the transceiver unit 12 is further configured to transmit a second frame, the second frame including second indication information, where the second indication information indicates that the EMLSR non-AP MLD is available.

[0329] It should be understood that the communication device in the first design may correspondingly realize embodiment 1, and the above-mentioned operations or functions of the units in the communication device are respectively used to realize the corresponding operations of EMLSR non-AP MLD in embodiment 1. For brevity, details will not be described again in this specification.

[0330] In a second design, the processing unit 11 is configured to generate a third frame. The third frame includes fourth indication information, where the fourth indication information indicates an available link or a link whose status has changed in the EMLSR non-AP MLD. The transceiver unit 12 is configured to transmit the third frame. Optionally, the third frame further includes third indication information, where the third indication information indicates that a link in the non-AP MLD has changed its status. The non-AP MLD is a non-AP MLD that supports the EMLSR mode.

[0331] It should be understood that the communication device in the second design may correspondingly realize embodiment 2, and the above-mentioned operations or functions of the units in the communication device are respectively used to realize the corresponding operations of EMLSR non-AP MLD in embodiment 2. For brevity, details will not be described again in this specification.

[0332] In a third design, after the EMLSR non-AP MLD and the associated AP MLD enter the EMLSR mode by exchanging EML OMN frames, the processing unit 11 is configured to generate a first EML OMN frame. The first EML OMN frame includes an EMLSR mode subfield and an EMLSR link bitmap, where the EMLSR mode subfield is set to 1, and the first EML OMN frame is used to notify the updated EMLSR link. The transceiver unit 12 is configured to transmit the first EML OMN frame to the AP MLD.

[0333] It should be understood that the communication device in the third design may correspondingly realize embodiment 3, and the above-mentioned operations or functions of the units in the communication device are respectively used to realize the corresponding operations of the EMLSR on-AP MLD in embodiment 3. For brevity, details will not be described again in this specification.

[0334] In a fourth design, the transceiver unit 12 is configured to receive a control frame. The control frame includes a first user information field, the first user information field includes an association identifier 12 subfield and indication information, the indication information indicates whether the control frame received by the station indicated by the association identifier 12 subfield is an initial control frame, and the EMLSR non-AP MLD has at least one receiving full capability link and at least one receiving restricted link. The processing unit 11 is configured to determine whether the received control frame is an initial control frame. The control frame is a MU-RTS frame or a BSRP frame.

[0335] It should be understood that the communication device in the fourth design may correspondingly realize embodiment 4, and the above-mentioned operations or functions of the units in the communication device are respectively used to realize the corresponding operations of EMLSR non-AP MLD in embodiment 4. For brevity, details will not be described again in this specification.

[0336] In a fifth design, the transceiver unit 12 is configured to receive a control frame. The control frame includes a common information field, the common information field includes indication information, and the indication information indicates whether the control frame is an initial control frame, and the EMLSR non-AP MLD has at least one receiving full-capability link and at least one receiving restricted link. The processing unit 11 is configured to determine whether the received control frame is an initial control frame. The control frame is an MU-RTS frame or a BSRP frame.

[0337] It should be understood that the communication device in the fifth design may correspondingly realize embodiment 5, and the above-mentioned operations or functions of the units in the communication device are respectively used to realize the corresponding operations of EMLSR non-AP MLD in embodiment 5. For brevity, details will not be described again in this specification.

[0338] In a sixth design, processing unit 11 is configured to generate a third frame, the third frame including fourth indication information, the fourth indication information indicating an available link or a link whose state is changing within the non-AP MLD, and transceiver unit 12 is configured to transmit the third frame.

[0339] It should be understood that the communication device in the sixth design may correspondingly realize the sixth embodiment, and the aforementioned operations or functions of the units in the communication device are respectively used to realize the corresponding operations of non-AP MLD in the sixth embodiment. For brevity, the details will not be described again in this specification.

[0340] 18 is reused. In some other embodiments of the present application, the communication device may be an AP MLD or a chip in the AP MLD, for example, a Wi-Fi chip. That is, the communication device may be configured to realize the steps or functions performed by the AP MLD in the above-mentioned method embodiments.

[0341] In one design, the transceiver unit 12 is configured to receive a first frame, the first frame including first indication information, the first indication information indicating that the EMLSR non-AP MLD is disabled for the AP MLD, and the processing unit 11 is configured to determine, based on the first indication information in the first frame, that the EMLSR non-AP MLD is disabled.

[0342] Optionally, the transceiver unit 12 is further configured to receive a second frame, the second frame including second indication information, where the second indication information indicates that EMLSR non-AP MLD is available.

[0343] It should be understood that the communication device in the design may correspondingly implement embodiment 1, and the above-mentioned operations or functions of the units in the communication device are respectively used to implement the corresponding operations of AP MLD in embodiment 1. For brevity, details will not be described again in this specification.

[0344] In one design, the transceiver unit 12 is configured to receive a third frame. The third frame includes fourth indication information, where the fourth indication information indicates an available link or a link whose status has changed in the EMLSR non-AP MLD. The processing unit 11 is configured to determine an available link of the EMLSR non-AP MLD based on the third indication information and the fourth indication information in the third frame. Optionally, the third frame further includes third indication information, where the third indication information indicates that a link of the non-AP MLD has changed status. The non-AP MLD is a non-AP MLD that supports the EMLSR mode.

[0345] It should be understood that the communication device in the design may correspondingly implement embodiment 2, and the above-mentioned operations or functions of the units in the communication device are respectively used to implement the corresponding operations of AP MLD in embodiment 2. For brevity, details will not be described again in this specification.

[0346] In one design, after the EMLSR non-AP MLD and the associated AP MLD enter the EMLSR mode by exchanging EML OMN frames, the transceiver unit 12 is configured to receive a first EML OMN frame, the first EML OMN frame includes an EMLSR mode subfield and an EMLSR link bitmap, the EMLSR mode subfield is set to 1, and the first EML OMN frame is used to notify the updated EMLSR link. The processing unit 11 is configured to determine an available link of the EMLSR non-AP MLD based on the first EML OMN frame.

[0347] It should be understood that the communication device in the design may correspondingly implement embodiment 3, and the above-mentioned operations or functions of the units in the communication device are respectively used to implement the corresponding operations of AP MLD in embodiment 3. For brevity, details will not be described again in this specification.

[0348] In one design, the processing unit 11 is configured to generate a control frame, the control frame including a first user information field, the first user information field including an association identifier 12 subfield and indication information, the indication information indicating whether the control frame received by the station indicated by the association identifier 12 subfield is an initial control frame, and the transceiver unit 12 is configured to transmit the control frame.

[0349] It should be understood that the communication device in the design may correspondingly implement embodiment 4, and the above-mentioned operations or functions of the units in the communication device are respectively used to implement the corresponding operations of AP MLD in embodiment 4. For brevity, details will not be described again in this specification.

[0350] In one design, processing unit 11 is configured to generate a control frame, the control frame including a common information field, the common information field including indication information, and the indication information indicating whether the control frame is an initial control frame. Transceiver unit 12 is configured to transmit the control frame.

[0351] It should be understood that the communication device in the design may correspondingly implement embodiment 5, and the above-mentioned operations or functions of the units in the communication device are respectively used to implement the corresponding operations of AP MLD in embodiment 5. For brevity, details will not be described again in this specification.

[0352] In one design, the transceiver unit 12 is configured to receive a third frame. The third frame includes fourth indication information, and the fourth indication information indicates an available link or a link whose status has changed in the non-AP MLD. Optionally, if the third frame further includes third indication information, the third indication information indicates whether the status of the link of the non-AP MLD has changed. Specifically, for the implementation of the third indication information and the fourth indication information, please refer to the above description. Details will not be described again in this specification. The processing unit 11 is configured to determine an available link of the non-AP MLD based on the fourth indication information in the third frame. Optionally, after the transceiver unit 12 of the AP MLD associated with the non-AP MLD receives the third frame, the processing unit 11 determines an available link of the non-AP MLD based on the third indication information and the fourth indication information carried in the third frame.

[0353] It should be understood that the communication device in the design may correspondingly implement embodiment 6, and the above-mentioned operations or functions of the units in the communication device are respectively used to implement the corresponding operations of AP MLD in embodiment 6. For brevity, details will not be described again in this specification.

[0354] The above describes the AP MLD and non-AP MLD in the embodiment of the present application. The following describes possible product forms of AP MLD and non-AP MLD. It should be understood that any product in any form having the function of the communication device described in FIG. 18 falls within the protection scope of the embodiment of the present application. It should be further understood that the following description is merely an example, and the product forms of AP MLD and non-AP MLD in the embodiment of the present application are not limited thereto.

[0355] As a possible product form, the AP MLD and non-AP MLD described in the embodiments of the present application may be implemented by using a common bus architecture.

[0356] For ease of explanation, please refer to Figure 19. Figure 19 is a schematic diagram of the structure of a communication device 1000 according to one embodiment of the present application. The communication device 1000 may be an AP MLD or a non-AP MLD, or may be a chip in an AP MLD or a non-AP MLD. Figure 19 shows only the main components of the communication device 1000. In addition to the processor 1001 and the transceiver 1002, the communication device may further include a memory 1003 and an input / output device (not shown).

[0357] The processor 1001 is primarily configured to process communication protocols and communication data, control communication devices, execute software programs, and process data of the software programs. The memory 1003 is primarily configured to store software programs and data. The transceiver 1002 may include a control circuit and an antenna. The control circuit is primarily configured to perform conversion between baseband signals and radio frequency signals, and process the radio frequency signals. The antenna is primarily configured to receive and transmit radio frequency signals in the form of electromagnetic waves. The input / output device, such as a touch screen, a display, or a keyboard, is primarily configured to receive data input by a user and output data to a user.

[0358] After the communication device is powered on, the processor 1001 can read the software program in the memory 1003, interpret and execute the instructions of the software program, and process the data of the software program. When data needs to be transmitted wirelessly, the processor 1001 performs baseband processing on the data to be transmitted, and then outputs the baseband signal to the radio frequency circuit. The radio frequency circuit performs radio frequency processing on the baseband signal, and then transmits the radio frequency signal in the form of an electromagnetic wave through an antenna. When data is transmitted to the communication device, the radio frequency circuit receives the radio frequency signal through the antenna, converts the radio frequency signal into a baseband signal, and outputs the baseband signal to the processor 1001. The processor 1001 converts the baseband signal into data and processes the data.

[0359] In another implementation, the radio frequency circuitry and antenna may be located separately from the processor for baseband processing, e.g., in a distributed scenario, the radio frequency circuitry and antenna may be located separately from the communication device.

[0360] The processor 1001, the transceiver 1002, and the memory 1003 may be connected via a communication bus.

[0361] In one design, the communication device 1000 may be configured to implement the functionality of the EMLSR non-AP MLD of embodiment 1. The processor 1001 may be configured to perform step S101 of FIG. 5 and / or another process of the techniques described herein. The transceiver 1002 may be configured to perform step S102 and step S105 of FIG. 5 and / or another process of the techniques described herein.

[0362] In another design, the communication device 1000 may be configured to realize the function of the AP MLD in embodiment 1. The processor 1001 may be configured to perform step S104 of FIG. 5 and / or another process of the techniques described herein. The transceiver 1002 may be configured to perform step S103 and step S106 of FIG. 5 and / or another process of the techniques described herein.

[0363] In one design, the communication device 1000 may be configured to implement the functionality of the EMLSR non-AP MLD of embodiment 2. The processor 1001 may be configured to perform step S201 of FIG. 8 and / or another process of the techniques described herein. The transceiver 1002 may be configured to perform step S202 of FIG. 8 and / or another process of the techniques described herein.

[0364] In another design, the communication device 1000 may be configured to implement the functionality of the AP MLD of embodiment 2. The processor 1001 may be configured to execute step S204 of FIG. 8 and / or another process of the techniques described herein. The transceiver 1002 may be configured to execute step S203 of FIG. 8 and / or another process of the techniques described herein.

[0365] In one design, the communication device 1000 may be configured to implement the functionality of the EMLSR non-AP MLD of embodiment 3. The processor 1001 may be configured to perform step S301 of FIG. 13 and / or another process of the techniques described herein. The transceiver 1002 may be configured to perform step S302 of FIG. 13 and / or another process of the techniques described herein.

[0366] In another design, the communication device 1000 may be configured to implement the functionality of the AP MLD of embodiment 3. The processor 1001 may be configured to execute step S304 of FIG. 13 and / or another process of the techniques described herein. The transceiver 1002 may be configured to execute step S303 of FIG. 13 and / or another process of the techniques described herein.

[0367] In one design, the communication device 1000 may be configured to implement the functionality of the EMLSR non-AP MLD of embodiment 4. The processor 1001 may be configured to perform step S404 of FIG. 14 and / or another process of the techniques described herein. The transceiver 1002 may be configured to perform step S403 of FIG. 14 and / or another process of the techniques described herein.

[0368] In another design, the communication device 1000 may be configured to implement the functionality of the AP MLD of embodiment 4. The processor 1001 may be configured to execute step S401 of FIG. 14 and / or another process of the techniques described herein. The transceiver 1002 may be configured to execute step S402 of FIG. 14 and / or another process of the techniques described herein.

[0369] In one design, the communication device 1000 may be configured to implement the functionality of the EMLSR non-AP MLD of embodiment 5. The processor 1001 may be configured to perform step S504 of FIG. 16 and / or another process of the techniques described herein. The transceiver 1002 may be configured to perform step S503 of FIG. 16 and / or another process of the techniques described herein.

[0370] In another design, the communication device 1000 may be configured to realize the function of the AP MLD of embodiment 5. The processor 1001 may be configured to execute step S501 of FIG. 16 and / or another process of the techniques described herein. The transceiver 1002 may be configured to execute step S502 of FIG. 16 and / or another process of the techniques described herein.

[0371] In any one of the aforementioned designs, the processor 1001 may include a transceiver configured to implement a transmitting and receiving function. For example, the transceiver may be a transceiver circuit, an interface, or an interface circuit. The transceiver circuit, the interface, or the interface circuit configured to implement the transmitting and receiving function may be separate or integrated. The transceiver circuit, the interface, or the interface circuit may be configured to read and write code / data. Alternatively, the transceiver circuit, the interface, or the interface circuit may be configured to transmit or forward a signal.

[0372] In any one of the above designs, the processor 1001 may store instructions. The instructions may be a computer program. The computer program is executed in the processor 1001, such that the communication device 1000 can perform the method described in any one of the above method embodiments. The computer program may be fixed to the processor 1001, in which case the processor 1001 may be implemented by hardware.

[0373] In one implementation, the communication device 1000 may include circuits that may perform the transmitting, receiving, or communication functions in the above-described method embodiments. The processors and transceivers described in this application may be implemented in integrated circuits (ICs), analog ICs, radio frequency integrated circuits (RFICs), mixed signal ICs, application specific integrated circuits (ASICs), printed circuit boards (PCBs), electronic devices, etc. The processors and transceivers may alternatively be fabricated using various IC technologies, such as complementary metal oxide semiconductor (CMOS), nMetal-oxide-semiconductor (NMOS), pMetal-oxide-semiconductor (PMOS), bipolar junction transistor (BJT), bipolar CMOS (BiCMOS), silicon germanium (SiGe), and gallium arsenide (GaAs).

[0374] The scope of the communication device described in this application is not limited in this respect, and the structure of the communication device may not be limited by FIG. 19. The communication device may be a separate device or may be part of a larger device. For example, the communication device may be: (1) An independent integrated circuit IC, chip, or chip system or subsystem; (2) a set including one or more ICs, optionally the set of ICs may further include a storage component configured to store data and computer programs; (3) ASICs such as modems (4) A module that can be incorporated into another device; (5) Receivers, terminals, intelligent terminals, cellular telephones, wireless devices, handheld devices, mobile units, vehicle-mounted devices, network devices, cloud devices, artificial intelligence devices, etc.; or (6)Other may be also possible.

[0375] In one possible product form, the AP MLD and non-AP MLD in the embodiments of the present application may be implemented by a general-purpose processor.

[0376] A general-purpose processor for implementing non-AP MLD includes a processing circuit and an input / output interface interconnected to and communicating with the processing circuit.

[0377] In one design, the general-purpose processor may be configured to implement the functionality of the EMLSR non-AP MLD in embodiment 1. Specifically, the processing circuit may be configured to perform step S101 of FIG. 5 and / or other processes of the techniques described herein. The input / output interface may be configured to perform step S102 and step S105 of FIG. 5 and / or other processes of the techniques described herein.

[0378] In one design, the general-purpose processor may be configured to implement the functionality of the EMLSR non-AP MLD in embodiment 2. Specifically, the processing circuit may be configured to perform step S201 of FIG. 8 and / or another process of the techniques described herein. The input / output interface may be configured to perform step S202 of FIG. 8 and / or another process of the techniques described herein.

[0379] In one design, the general-purpose processor may be configured to implement the functionality of the EMLSR non-AP MLD in embodiment 3. Specifically, the processing circuit may be configured to perform step S301 of FIG. 13 and / or another process of the techniques described herein. The input / output interface may be configured to perform step S302 of FIG. 13 and / or another process of the techniques described herein.

[0380] In one design, the general-purpose processor may be configured to implement the functionality of the EMLSR non-AP MLD in embodiment 4. Specifically, the processing circuit may be configured to perform step S404 of FIG. 14 and / or another process of the techniques described herein. The input / output interface may be configured to perform step S403 of FIG. 14 and / or another process of the techniques described herein.

[0381] In one design, the general-purpose processor may be configured to implement the functionality of the EMLSR non-AP MLD in embodiment 5. Specifically, the processing circuit may be configured to perform step S504 of FIG. 16 and / or another process of the techniques described herein. The input / output interface may be configured to perform step S503 of FIG. 16 and / or another process of the techniques described herein.

[0382] A general-purpose processor for implementing the AP MLD includes a processing circuit and an input / output interface interconnected to and communicating with the processing circuit.

[0383] In one design, a general-purpose processor may be configured to implement the functionality of the AP MLD of embodiment 1. Specifically, the processing circuit may be configured to perform step S104 of FIG. 5 and / or other processes of the techniques described herein. The input / output interface may be configured to perform steps S103 and S106 of FIG. 5 and / or other processes of the techniques described herein.

[0384] In one design, a general-purpose processor may be configured to implement the functionality of the AP MLD of embodiment 2. Specifically, the processing circuit may be configured to perform step S204 of FIG. 8 and / or another process of the techniques described herein. The input / output interface may be configured to perform step S203 of FIG. 8 and / or another process of the techniques described herein.

[0385] In one design, a general-purpose processor may be configured to implement the functionality of the AP MLD of embodiment 3. Specifically, the processing circuit may be configured to perform step S304 of FIG. 13 and / or another process of the techniques described herein. The input / output interface may be configured to perform step S303 of FIG. 13 and / or another process of the techniques described herein.

[0386] In one design, a general-purpose processor may be configured to implement the functionality of the AP MLD of embodiment 4. Specifically, the processing circuit may be configured to perform step S401 of FIG. 14 and / or another process of the techniques described herein. The input / output interface may be configured to perform step S402 of FIG. 14 and / or another process of the techniques described herein.

[0387] In one design, a general-purpose processor may be configured to implement the functionality of the AP MLD of embodiment 5. Specifically, the processing circuit may be configured to perform step S501 of FIG. 16 and / or another process of the techniques described herein. The input / output interface may be configured to perform step S502 of FIG. 16 and / or another process of the techniques described herein.

[0388] It should be understood that the communication devices in the above various product forms have any function of AP MLD or EMLSR non-AP MLD in the method embodiments, and the details are not described again in this specification.

[0389] An embodiment of the present application further provides a computer-readable storage medium, which stores computer program code, and when a processor executes the computer program code, the electronic device performs the method in any one of the preceding embodiments.

[0390] An embodiment of the present application further provides a computer program product, which, when running on a computer, enables the computer to perform the method in any one of the preceding embodiments.

[0391] An embodiment of the present application further provides a communication device. The device may be in the form of a chip product. The structure of the device includes a processor and an interface circuit. The processor is configured to communicate with other devices through the interface circuit to enable the device to perform the method in any one of the previous embodiments.

[0392] An embodiment of the present application further provides a wireless communication system including an AP MLD and a non-AP MLD. The AP MLD and the non-AP MLD may perform the method in any one of the preceding embodiments.

[0393] The steps of the method or algorithm described in conjunction with the contents disclosed in this application may be implemented by hardware or by a processor by executing software instructions. The software instructions may include corresponding software modules. The software modules may be stored in a Random Access Memory (RAM), a flash memory, an Erasable Programmable Read Only Memory (EPROM), an Electrically Erasable Programmable Read Only Memory (EEPROM), a register, a hard disk, a removable hard disk, a Compact Disk Read Only Memory (CD-ROM), or any other form of storage medium known in the art. For example, the storage medium is coupled to the processor such that the processor can read information from the storage medium and write information to the storage medium. Of course, the storage medium may be components of the processor. The processor and the storage medium may be located in an ASIC. In addition, the ASIC may be located in a core network interface device. Of course, the processor and the storage medium may reside in a core network interface device as separate components.

[0394] In one or more of the above examples, those skilled in the art should recognize that the functions described in the present application may be implemented by hardware, software, firmware, or any combination thereof. If the functions are implemented by software, the functions described above may be stored on a computer-readable medium or transmitted as one or more instructions or codes in a computer-readable medium. Computer-readable media include computer-readable storage media and communication media. Communication media include any medium that facilitates the transmission of a computer program from one place to another. Storage media may be any available medium accessible by a general-purpose or special-purpose computer.

[0395] In the above specific implementation, the objectives, technical solutions and beneficial effects of the present application are described in more detail. It should be understood that the above description is only a specific implementation of the present application, and is not intended to limit the protection scope of the present application. Any modifications, equivalent replacements, improvements, etc. made based on the technical solutions of the present application shall fall within the protection scope of the present application. [Explanation of symbols]

[0396] 1 Link, Channel 2 Links, Channels 11 Processing Unit 12 Transceiver unit 100 AP MLD 200 non-AP MLD 300 non-AP MLD 400 STA 1000 Communication Equipment 1001 Processor 1002 Transceiver 1003 Memory

Claims

1. generating a third frame by a non-AP MLD device, the third frame including a fourth indication, the fourth indication indicating an available link or a link whose status is changing within the non-AP MLD; transmitting the third frame by the non-AP MLD; A link state indication method comprising:

2. receiving a third frame by an access point multilink device (AP MLD), the third frame including a fourth indication, the fourth indication indicating an available link or a link whose status is changing within the non-AP MLD; determining an available link of the non-AP MLD based on the fourth indication information in the third frame by the AP MLD; A link state indication method comprising:

3. 3. The method of claim 1 or 2, wherein the third frame further includes third indication information, the third indication information indicating that a link status of the non-AP MLD has changed, and the non-AP MLD is a non-AP MLD in a support mode.

4. The change in the state of the non-AP MLD link includes the link being disabled, the third indication indicates that there is a disabled link; The method of claim 3 , wherein the fourth indication information indicates an available link of the non-AP MLD, or the fourth indication information indicates a disabled link of the non-AP MLD.

5. The change in the state of the non-AP MLD link includes a change from an unavailable link of the non-AP MLD to an available link; The third indication information indicates that an unavailable link has changed among the available links in the non-AP MLD; 4. The method of claim 3, wherein the fourth indication information indicates an available link of the non-AP MLD, or the fourth indication information indicates an EMLSR link that has changed from unavailable to available in the non-AP MLD.

6. The change in the state of the non-AP MLD link includes the link being disabled or the non-AP MLD unavailable link being changed to an available link; The third indication information specifically indicates that there is a disabled link, and that no unavailable link has changed to an available link in the non-AP MLD; or The method of claim 3 , wherein the third indication information specifically indicates that there is no disabled link and that there is an unavailable link that has changed to an available link in the non-AP MLD.

7. The third indication information and the fourth indication information may be disposed in an AP assistance request control subfield of a high throughput HT control field of the third frame; or The method according to claim 3 , wherein the third indication information and the fourth indication information can be placed in an aggregation control A-control subfield of the third frame.

8. 7. The method according to claim 3, wherein the third frame is an enhanced multilink EML operation mode notification OMN frame, the third indication information and the fourth indication information can be placed in an EML control field of the third frame, and an EMLSR mode subfield included in the EML control field is set to 1.

9. The method of claim 8, wherein the EML control field further includes one or more of the following information: disable start time, availability start time, disable end time, disable duration, and transmission / reception capability of an available link of an EMLSR non-AP MLD.

10. the fourth indication information is a bitmap, and one bit of the fourth indication information corresponds to one link; When a bit in the fourth indication is set to a first value, it indicates that the link corresponding to the bit is an available link or a link whose status is changing, or when a bit in the fourth indication is set to a second value, it indicates that the link corresponding to the bit is an unavailable link or a link whose status is not changing.

10. The method according to any one of claims 1 to 9.

11. A processing unit configured to generate a third frame, the third frame including a fourth indication, the fourth indication indicating an available link or a link whose state is changing within a non-AP MLD; a transceiver unit configured to transmit the third frame; A communication device comprising:

12. a transceiver unit configured to receive a third frame, the third frame including a fourth indication, the fourth indication indicating an available link or a link whose state is changing within a non-AP MLD; a processing unit configured to determine an available link of the non-AP MLD based on the fourth indication information in the third frame; A communication device comprising:

13. The communication device according to claim 11 or 12, wherein the third frame further includes third indication information, the third indication information indicating that a link status of the non-AP MLD has changed, and the non-AP MLD is a non-AP MLD supporting an EMLSR mode or a non-AP MLD supporting an NSTR mode.

14. The change in the state of the non-AP MLD link includes the link being disabled, the third indication indicates that there is a disabled link; The communication device according to claim 13 , wherein the fourth indication information indicates an available link of the non-AP MLD, or the fourth indication information indicates a disabled link of the non-AP MLD.

15. The change in the state of the non-AP MLD link includes a change from an unavailable link of the non-AP MLD to an available link; The third indication information indicates that an unavailable link has changed among the available links in the non-AP MLD; 14. The communication device of claim 13, wherein the fourth indication information indicates an available link in the non-AP MLD, or the fourth indication information indicates a link in the non-AP MLD that has changed from unavailable to available.

16. The change in the state of the non-AP MLD link includes the link being disabled or the non-AP MLD unavailable link being changed to an available link; The third indication information specifically indicates that there is a disabled link, and that no unavailable link has changed to an available link in the non-AP MLD; or 14. The communication device of claim 13, wherein the third indication information specifically indicates that there is no disabled link and that there is an unavailable link that has changed to an available link in the non-AP MLD.

17. The third indication information and the fourth indication information may be disposed in an AP assistance request control subfield of a high throughput HT control field of the third frame; or The communication device according to claim 13, wherein the third indication information and the fourth indication information can be placed in an aggregation control A-control subfield of the third frame.

18. 17. The communication device of claim 13, wherein the third frame is an extended multilink EML operation mode notification OMN frame, the third indication information and the fourth indication information can be placed in an EML control field of the third frame, and an EMLSR mode subfield included in the EML control field is set to 1.

19. The communication device of claim 18, wherein the EML control field further includes one or more of the following information: disable start time, available start time, disable end time, disable duration, and transmission / reception capabilities of the EMLSR non-AP MLD available link.

20. the fourth indication information is a bitmap, and one bit of the fourth indication information corresponds to one link; When a bit in the fourth indication is set to a first value, it indicates that the link corresponding to the bit is an available link or a link whose status is changing, or when a bit in the fourth indication is set to a second value, it indicates that the link corresponding to the bit is an unavailable link or a link whose status is not changing.

20. A communication device according to any one of claims 11 to 19.

21. A communications device comprising a processor and a transceiver, the transceiver configured to transmit and receive frames, and the processor configured to execute program instructions to enable the communications device to perform a method according to any one of claims 1 to 10.

22. 11. A computer-readable storage medium having stored thereon program instructions which, when executed in a computer, enable the computer to carry out the method according to any one of claims 1 to 10.

23. A computer program product comprising program instructions, which when executed in a computer, enable the computer to carry out the method according to any one of claims 1 to 10.

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