Method and related apparatus for restoring permission to use transmission opportunities

Abstract

This application relates to the field of wireless communication, and more particularly to a method for restoring permission to use a transmission opportunity and related apparatus. [Solution] This method includes the following: A first device receives a first frame from a second device. The first device recovers permission to use a transmit opportunity TXOP based on the first frame. The first frame indicates that the second device has stopped using the first time resource. The first time resource is allocated to the second device by the first device from the acquired TXOP by using a single-user trigger frame. According to embodiments of the present invention, the first frame can indicate that the second device has stopped using the allocated time resource (first time resource), and therefore the first device preemptively revokes / recovers permission to use the TXOP based on the indication of the first frame. This improves the reliability of channel resource utilization and recovery of permission to use the TXOP.

Description

Technical Field

[0001] This application claims priority to Chinese Patent Application No. 202110056633.4, titled "Method and Related Device for Recovering Permission to Use Transmission Opportunity", filed with the China National Intellectual Property Administration on January 15, 2021, and Chinese Patent Application No. 202110437428.2, titled "Method and Related Device for Recovering Permission to Use Transmission Opportunity", filed with the China National Intellectual Property Administration on April 22, 2021, the entire contents of which are hereby incorporated by reference in their entirety.

[0002] Technical Field This application relates to the field of wireless communication technologies, particularly to a method and related device for recovering permission to use a transmission opportunity.

Background Art

[0003] The 802.11 protocol suite is a communication standard defined by the Institute of Electrical and Electronics Engineers (IEEE) for wireless local area networks (WLANs). It starts from IEEE 802.11a / b / g and goes up to IEEE 802.11n and IEEE 802.11ac, and IEEE 802.11ax and IEEE 802.11be are under development.

[0004] In general, the physical layer (PHY) frame in the IEEE 802.11 standard is also called the PHY protocol data unit (PPDU). The IEEE 802.11ax standard proposes four frame structures: high efficiency single-user PPDU (HE SU PPDU), high efficiency multi-user PPDU (HE MU PPDU), high efficiency trigger-based PPDU (HE TB PPDU), and high efficiency extended range PPDU (HE ER PPDU). In the IEEE 802.11ax standard, HE SU PPDU is applied to scenarios where a station (STA) transmits data to another STA, and can be applied to both uplink and downlink transmissions. HE TB PPDU is applicable to scenarios where an access point (AP) sends a trigger frame (TF) to schedule a non-AP STA for uplink transmission.

[0005] In the current IEEE 802.11ax standard, trigger frames can only trigger HE TB PPDUs, not HE SU PPDUs. However, since APs typically have more powerful channel access capabilities, the next-generation IEEE 802.11be standard needs to support AP-triggered SU PPDUs. Therefore, to implement AP-triggered SU PPDUs, an AP may send a single-user trigger frame to allocate some or all of the remaining time resources in a transmission opportunity (TXOP) to an associated STA (hereinafter referred to as a designated STA for simplicity). This allows the designated STA to communicate with another STA or AP during the allocated time resources. However, if the duration of the time resource allocated to a designated STA by the AP is long, and the designated STA completes the necessary transmission after using the said time resource for a certain period (i.e., there is remaining duration in the allocated time resource), or if, after using the said time resource for a certain period, the designated STA finds that the remaining duration is insufficient to transmit a complete SU PPDU, the remaining duration becomes a waste of channel resources, and may allow another station to obtain permission to use the channel through competition. However, the AP cannot recover permission to use the said TXOP. Therefore, how to improve channel utilization and the reliability of TXOP recovery is an urgent issue that needs to be addressed now. [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] Embodiments of the present invention provide a method and associated apparatus for restoring permission to use a transmit opportunity to improve channel resource utilization and the reliability of restoring permission to use TXOP.

[0007] The following describes the present invention from different perspectives. It should be understood that the following implementations and beneficial effects of these different perspectives can be cross-referenced. [Means for solving the problem]

[0008] In a first aspect, the present invention provides a method for restoring permission to use a transmit opportunity. This method includes: a first device receives a first frame from a second device; the first device restores permission to use a TXOP based on the first frame; the first frame indicates that the second device has stopped using the first time resource; the first time resource is allocated to the second device by the first device using a single-user trigger frame, from the acquired transmit opportunity TXOP; that is, the second device may restore permission to use the TXOP by sending the first frame to the first device. The first device may be an AP, the second device may be an STA, or the second device may be another AP.

[0009] In this embodiment of the present application, the first frame may indicate that the second device has stopped using the allocated time resource (first time resource), and thus the first device may revoke / recover permission to use TXOP in advance based on the first frame received from the second device. This improves the utilization rate of the channel resource. In this embodiment, where permission to use TXOP is returned by transmitting the first frame, other stations may not be able to obtain permission to use the channel through competition for the remaining duration included in the first time resource. This improves the reliability of recovering permission to use TXOP.

[0010] With respect to the first aspect, in a feasible implementation, the first time resource is used for the transmission of Single User Physical Layer Protocol Data Units (PPDUs) on the uplink or for point-to-point P2P communication, and the Single User Trigger Frame includes a first field and a second field. The first field indicates the remaining time resource of the TXOP, and the second field indicates the first time resource. In other words, this embodiment of the present application is applicable to AP-triggered SU PPDU scenarios. Thus, channel resource utilization and TXOP recovery reliability in trigger-based SU PPDU scenarios can be improved.

[0011] Regarding the first aspect, in a feasible implementation, the first frame carries first instruction information. This first instruction information indicates that the second device has stopped using the first time resource. Specifically, the first device parses the first instruction information carried in the first frame and, based on the first instruction information, revokes / recovers permission to use TXOP in advance. This can improve channel resource utilization.

[0012] Regarding the first aspect, in a feasible implementation, the first frame further carries second instruction information. This second instruction information indicates whether the second device requires additional time resources for data transmission.

[0013] In this embodiment of the present application, the first device parses the first and second instruction information carried in the first frame so that the first device can preemptively revoke / recover permission to use the TXOP and know whether the second device has further time resource allocation requests. For example, if the duration of the time resource allocated to the second device by the first device (i.e., the first time resource) is short, and the second device has used the time resource for a certain period of time and has not completed the necessary transmissions, but the remaining duration of the first time resource is insufficient to transmit a complete SU PPDU, the first device can preemptively revoke / recover permission to use the TXOP by using the first frame carrying the first and second instruction information, thereby preventing waste of the remaining duration. Furthermore, the second device can reapply to the first device for time resources, reducing the signal transmission overhead used to apply for time resources.

[0014] With respect to the first aspect, in a feasible implementation, the A control field in the first frame contains first instruction information, or the A control field in the first frame contains both first and second instruction information. In other words, the meaning of the A control field contained in existing types of frames (e.g., QoS data frames or QoS null data frames) is improved / modified to indicate that a second device has stopped using the first time resource. This can reduce the complexity of implementing the solution.

[0015] With respect to the first aspect, in a feasible implementation, the control identifier of the A control field is a first value. The first value indicates that the A control field contains first instruction information. That is, in this embodiment of the present application, the new A control field is designed to indicate that the second device has stopped using the first time resource. This can improve the versatility of implementing the solution.

[0016] With respect to the first aspect, in a feasible implementation, the control identifier of the A control field is a second value. The second value indicates that the A control field is a command and status CAS control field. The first instruction information is carried in the reverse approval RDG subfield within the CAS control field, and the second instruction information is carried in at least one bit between the 4th and 8th bits within the CAS control field.

[0017] In this embodiment of the present application, the existing A control field (i.e., the CAS control field) is improved to indicate that the second device has stopped using the first time resource, or that the second device has stopped using the first time resource and also indicates whether the second device requires further time resources for data transmission. This can further simplify the complexity of implementing the solution.

[0018] With respect to the first aspect, in one feasible implementation, the frame type field in the first frame indicates that the first frame is a control frame, and the frame subtype field in the first frame indicates that the first frame is a time resource return frame. The time resource return frame indicates that the second device has stopped using the first time resource. In other words, in this embodiment of the present application, a new type of frame is designed to specifically indicate that the second device has returned permission to use the TXOP. This can improve the flexibility and versatility of implementing the solution.

[0019] In a second aspect, the present invention provides a method for restoring permission to use a transmission opportunity. This method includes: a second device determines a first frame and transmits the first frame to the first device. The first frame indicates that the second device has stopped using the first time resource. The first time resource is allocated to the second device by the first device from the acquired transmission opportunity TXOP by using a single-user trigger frame.

[0020] Regarding the second aspect, in a feasible implementation, the first time resource is used for the transmission of single-user physical layer protocol data units (PPDUs) on the uplink, or for point-to-point P2P communication, and the single-user trigger frame includes a first field and a second field. The first field indicates the remaining time resource of the TXOP, and the second field indicates the first time resource.

[0021] Regarding the second aspect, in a feasible implementation, the first frame carries first instruction information, which indicates that the second device has stopped using the first time resource.

[0022] Regarding the second aspect, in a feasible implementation, the first frame further carries second instruction information. This second instruction information indicates whether the second device requires additional time resources for data transmission.

[0023] With respect to the second aspect, in a feasible implementation, the A control field in the first frame contains first instruction information, or the A control field in the first frame contains both first and second instruction information.

[0024] Regarding the second aspect, in a feasible implementation, the control identifier of the A control field is a first value. The first value indicates that the A control field contains first instruction information.

[0025] Regarding the second aspect, in one possible implementation, the control identifier of the A control field is a second value. The second value indicates that the A control field is a command and status CAS control field.

[0026] The first instruction information is carried in the inverse approval RDG subfield within the CAS control field.

[0027] Alternatively, the first instruction information is carried in the RDG subfield within the CAS control field, and the second instruction information is carried in at least one bit among bits 4 to 8 within the CAS control field.

[0028] Regarding the second aspect, in one possible implementation, the frame type field within the first frame indicates that the first frame is a control frame, and the frame subtype field within the first frame indicates that the first frame is a time resource return frame. The time resource return frame indicates that the second device has stopped using the first time resource.

[0029] Regarding the second aspect, in one possible implementation, when the first frame is a quality of service (QoS) null data frame or when the first frame is a time resource return frame, and if the end point of the first frame is after the end point of the first time resource and the start point of the first frame is before the end point of the first time resource, the second device is permitted to transmit the first frame to the first device.

[0030] In this embodiment of the present application, if the first frame is a Quality of Service (QoS) null data frame, or if the first frame is a new type of frame specifically indicating a return, the first frame is permitted to be transmitted after the end of the first time resource. In this way, other stations may not be able to obtain permission to use the channel through competition in the first time resource, and the reliability of recovering permission to use TXOP is improved.

[0031] In a third aspect, the present invention provides a method for restoring permission to use a transmit opportunity. This method includes: a first device receives a second frame. If the duration between the end of transmission of the second frame and the end of the first time resource is shorter than a predetermined duration T, the first device restores permission to use the transmit opportunity TXOP. The destination address of the second frame is the address of the second device. Alternatively, the sender address of the second frame is the address of the second device, and the second frame is a frame that does not request a response frame. The first time resource is allocated by the first device to the second device from the acquired TXOP. That is, the first device may determine whether to restore permission to use the TXOP by determining the value relationship between a time threshold (i.e., a predetermined duration T) and the duration T' between the end of reception of the second frame and the end of the first time resource. In this solution, a time threshold T is set. Even if T' is less than T, permission to use TXOP may be restored in advance to improve channel resource utilization.

[0032] Regarding the third aspect, in a feasible implementation, if the duration between the end of the second frame and the end of the first time resource is greater than T, the first device receives the first frame from the second device. The first frame indicates that the second device has stopped using the first time resource.

[0033] In this embodiment of the present application, if T' is greater than T, the first frame may indicate that the second device has stopped using the allocated time resource (first time resource), and thus the first device can preemptively revoke / recover permission to use TXOP based on the first frame received from the second device. This improves the utilization rate of the channel resource. Furthermore, other stations may not be able to obtain permission to use the channel through competition during the remaining duration included in the first time resource, thus improving the reliability of recovering permission to use TXOP.

[0034] With respect to the third aspect, in a feasible implementation, the first time resource is used for the transmission of Single User Physical Layer Protocol Data Units (PPDUs) on the uplink or for point-to-point P2P communication, and the Single User Trigger Frame includes a first field and a second field. The first field indicates the remaining time resource of the TXOP, and the second field indicates the first time resource. In other words, this embodiment of the present application is applicable to AP-triggered SU PPDU scenarios. Thus, channel resource utilization and TXOP recovery reliability in trigger-based SU PPDU scenarios can be improved.

[0035] Regarding the third aspect, in one feasible implementation, the first frame carries first instruction information. This first instruction information indicates that the second device has stopped using the first time resource. Specifically, the first device parses the first instruction information carried in the first frame and, based on this information, revoks / recovers permission to use TXOP in advance. This can improve channel resource utilization.

[0036] Regarding the third aspect, in a feasible implementation, the first frame further carries second instruction information. This second instruction information indicates whether the second device requires additional time resources for data transmission.

[0037] In this embodiment of the present application, the first device parses the first and second instruction information carried in the first frame so that the first device can preemptively revoke / recover permission to use TXOP and further know whether the second device has further time resource allocation requests. For example, if the duration of the time resource allocated to the second device by the first device (i.e., the first time resource) is short, and the second device has used the time resource for a period of time and finds that it has not completed the necessary transmissions, but the remaining duration of the first time resource is insufficient to transmit a complete SU PPDU, the first device can preemptively revoke / recover permission to use TXOP by using the first frame carrying the first and second instruction information, thereby preventing the waste of the remaining duration. Furthermore, the second device may reapply to the first device for time resources, reducing the overhead of signal transmission used to apply for time resources.

[0038] With respect to the third aspect, in a feasible implementation, the A control field in the first frame contains first instruction information, or the A control field in the first frame contains both first and second instruction information. In other words, the meaning of the A control field contained in existing types of frames (e.g., QoS data frames or QoS null data frames) is improved / modified to indicate that the second device has stopped using the first time resource. This can reduce the complexity of implementing the solution.

[0039] With respect to the third aspect, in one feasible implementation, the control identifier of the A control field is a first value. The first value indicates that the A control field contains first instruction information. That is, in this embodiment of the present application, a new A control field is designed to indicate that the second device has stopped using the first time resource. This can improve the versatility of implementing the solution.

[0040] With respect to the third aspect, in a feasible implementation, the control identifier of the A control field is a second value. The second value indicates that the A control field is a command and status CAS control field. The first instruction information is carried in the reverse approval RDG subfield within the CAS control field. Alternatively, the first instruction information is carried in the RDG subfield within the CAS control field, and the second instruction information is carried in at least one bit in bits 4 through 8 within the CAS control field.

[0041] In this embodiment of the present application, the existing A control field (i.e., the CAS control field) is improved to indicate that the second device has stopped using the first time resource, or that the second device has stopped using the first time resource and indicates whether the second device requires further time resources for data transmission. This can further simplify the complexity of implementing the solution.

[0042] With respect to the third aspect, in one feasible implementation, the frame type field within the first frame indicates that the first frame is a control frame, and the frame subtype field within the first frame indicates that the first frame is a time resource return frame. The time resource return frame indicates that the second device has stopped using the first time resource. In other words, in this embodiment of the present application, a new type of frame is designed specifically to indicate that the second device is returning permission to use the TXOP. This can improve the flexibility and versatility of implementing the solution.

[0043] According to a fourth aspect, the present invention provides a method for restoring permission to use a transmission opportunity. This method includes: a second device receives or transmits a second frame; the second frame is a frame that does not request a response frame; and if the duration between the end of the second frame and the end of the first time resource is shorter than a predetermined duration T, the second device does not transmit any further PPDUs.

[0044] Specifically, when the second device receives an acknowledgment frame (i.e., the second frame) at any point in the first time resource, or sends a frame that does not request a response frame (i.e., the second frame) at any point in the first time resource, if the duration T' between the end of the second frame and the end of the first time resource is determined to be shorter than T, the second device defaults to assuming that the first device has recovered the use of TXOP. In other words, the second device is no longer permitted to send SU PPDUs for the remaining duration of the first time resource, thus preventing the second device from failing to send SU PPDUs.

[0045] Regarding the fourth aspect, in a feasible implementation, if the duration between the end of the second frame and the end of the first time resource is greater than a predetermined duration T, the second device sends a first frame to the first device. The first frame indicates that the second device has stopped using the first time resource. The first time resource is then allocated to the second device by the first device from the acquired TXOP.

[0046] In other words, if T' is greater than T, the first frame may indicate that the second device has stopped using the allocated time resource (the first time resource). Therefore, the first device can preemptively revoke / recover permission to use TXOP based on the first frame received from the second device. Thus, channel resource utilization is improved. Furthermore, the reliability of recovering permission to use TXOP is improved because other stations may not be able to obtain permission to use the channel through competition for the remaining duration included in the first time resource.

[0047] With respect to the fourth aspect, in a feasible implementation, the first time resource is used for the transmission of single-user physical layer protocol data units (PPDUs) on the uplink, or for point-to-point P2P communication, and the single-user trigger frame includes a first field and a second field. The first field indicates the remaining time resource of the TXOP, and the second field indicates the first time resource.

[0048] Regarding the fourth aspect, in a feasible implementation, the first frame carries first instruction information, which indicates that the second device has stopped using the first time resource.

[0049] Regarding the fourth aspect, in a feasible implementation, the first frame further carries second instruction information, which indicates whether the second device requires additional time resources for data transmission.

[0050] With respect to the fourth aspect, in a feasible implementation, the A control field in the first frame contains first instruction information, or the A control field in the first frame contains first instruction information and second instruction information.

[0051] With respect to the fourth aspect, in a feasible implementation, the control identifier of the A control field is a first value. The first value indicates that the A control field contains first instruction information.

[0052] Regarding the fourth aspect, in a feasible implementation, the control identifier of the A control field is a second value. The second value indicates that the A control field is a command and status CAS control field.

[0053] The first instruction information is carried in the reverse approval RDG subfield within the CAS control field.

[0054] Alternatively, the first instruction information may be carried in the RDG subfield within the CAS control field, and the second instruction information may be carried in at least one bit in bits 4 through 8 within the CAS control field.

[0055] With respect to the fourth aspect, in one feasible implementation, the frame type field within the first frame indicates that the first frame is a control frame, and the frame subtype field within the first frame indicates that the first frame is a time resource return frame. The time resource return frame indicates that the second device has stopped using the first time resource.

[0056] With respect to the fourth aspect, in a feasible implementation, if the first frame is a Quality of Service (QoS) null data frame, or if the first frame is a time resource return frame, the second device is permitted to send the first frame to the first device if the end of the first frame is after the end of the first time resource and the start of the first frame is earlier than the end of the first time resource.

[0057] In this embodiment of the present application, if the first frame is a Quality of Service (QoS) null data frame, or if the first frame is a new type of frame specifically indicating a return, the first frame may be transmitted after the end of the first time resource. In this way, other stations do not need to obtain permission to use the channel through competition for the remaining duration included in the first time resource, and the reliability of recovering permission to use TXOP is improved.

[0058] According to a fifth aspect, the present invention provides a method for restoring permission to use a transmission opportunity. This method includes: a first device transmits a second frame, where the destination address of the second frame is the address of the second device. If the duration between the end of the second frame and the end of the first time resource is shorter than a pre-configured duration T, the first device restores permission to use the transmission opportunity TXOP. The first time resource is allocated to the second device by the first device from the acquired TXOP. In other words, in the UL scenario, the first device can transmit an acknowledgment frame (i.e., a second frame) with the address of the second device as its destination address at any point in the first time resource. If the first device determines that the duration T' between the end of the acknowledgment frame and the end of the first time resource is shorter than a pre-configured duration T, it may restore permission to use the TXOP in advance to improve the utilization of the channel resource.

[0059] With respect to the fifth aspect, in a feasible implementation, if the duration between the end of the second frame and the end of the first time resource is greater than T, the first device receives the first frame from the second device. The first frame indicates that the second device has stopped using the first time resource.

[0060] With respect to the fifth aspect, in a feasible implementation, the first time resource is used for the transmission of single-user physical layer protocol data units (PPDUs) on the uplink or for point-to-point P2P communication, and the single-user trigger frame includes a first field and a second field. The first field indicates the remaining time resource of the TXOP, and the second field indicates the first time resource.

[0061] With respect to the fifth aspect, in a feasible implementation, the first frame carries first instruction information, which indicates that the second device has stopped using the first time resource.

[0062] With respect to the fifth aspect, in a feasible implementation, the first frame further carries second instruction information, which indicates whether the second device requires additional time resources for data transmission.

[0063] With respect to the fifth aspect, in a feasible implementation, the A control field in the first frame contains first instruction information, or the A control field in the first frame contains first instruction information and second instruction information.

[0064] With respect to the fifth aspect, in a feasible implementation, the control identifier of the A control field is a first value. The first value indicates that the A control field contains first instruction information.

[0065] Regarding the fifth aspect, in a feasible implementation, the control identifier of the A control field is a second value. The second value indicates that the A control field is a command and status CAS control field.

[0066] The first instruction information is carried in the reverse approval RDG subfield within the CAS control field.

[0067] Alternatively, the first instruction information may be carried in the RDG subfield within the CAS control field, and the second instruction information may be carried in at least one bit in bits 4 through 8 within the CAS control field.

[0068] With respect to the fifth aspect, in one feasible implementation, the frame type field within the first frame indicates that the first frame is a control frame, and the frame subtype field within the first frame indicates that the first frame is a time resource return frame. The time resource return frame indicates that the second device has stopped using the first time resource.

[0069] According to the sixth aspect, the present invention provides a method for restoring permission to use a transmission opportunity. This method includes: a second device receives a second frame from a first device; if the duration between the end of the second frame and the end of the first time resource is shorter than a predetermined duration T, the second device does not transmit any further PPDUs.

[0070] With respect to the sixth aspect, in a feasible implementation, if the duration between the end of the second frame and the end of the first time resource is longer than a predetermined duration T, the second device sends the first frame to the first device. The first frame indicates that the second device has stopped using the first time resource. The first time resource is then allocated to the second device by the first device from the acquired TXOP.

[0071] With respect to the sixth aspect, in a feasible implementation, the first time resource is used for the transmission of Single User Physical Layer Protocol Data Units (PPDUs) on the uplink or for point-to-point P2P communication, and the Single User Trigger Frame includes a first field and a second field. The first field indicates the remaining time resource of the TXOP, and the second field indicates the first time resource.

[0072] With respect to the sixth aspect, in a feasible implementation, the first frame carries first instruction information, which indicates that the second device has stopped using the first time resource.

[0073] With respect to the sixth aspect, in a feasible implementation, the first frame further carries second instruction information, which indicates whether the second device requires additional time resources for data transmission.

[0074] With respect to the sixth aspect, in a feasible implementation, the A control field in the first frame contains first instruction information, or the A control field in the first frame contains first instruction information and second instruction information.

[0075] With respect to the sixth aspect, in a feasible implementation, the control identifier of the A control field is a first value. The first value indicates that the A control field contains first instruction information.

[0076] Regarding the sixth aspect, in one feasible implementation, the control identifier of the A control field is a second value. The second value indicates that the A control field is a command and status CAS control field.

[0077] The first instruction information is carried in the reverse approval RDG subfield within the CAS control field.

[0078] Alternatively, the first instruction information may be carried in the RDG subfield within the CAS control field, and the second instruction information may be carried in at least one bit in bits 4 through 8 of the CAS control field.

[0079] With respect to the sixth aspect, in one feasible implementation, the frame type field within the first frame indicates that the first frame is a control frame, and the frame subtype field within the first frame indicates that the first frame is a time resource return frame. A time resource return frame indicates that the second device has stopped using the first time resource.

[0080] With respect to the sixth aspect, in a feasible implementation, if the first frame is a Quality of Service (QoS) null data frame, or if the first frame is a time resource return frame, the second device is permitted to send the first frame to the first device if the end of the first frame is after the end of the first time resource and the start of the first frame is earlier than the end of the first time resource.

[0081] According to the seventh aspect, the present invention provides a method for restoring permission to use a transmission opportunity. This method includes: a first device determining a third frame, and the first device transmitting the third frame to a second device; the third frame indicating that the first device has actively restored permission to use a transmission opportunity TXOP.

[0082] In this embodiment of the present application, if an AP needs to revoke its authorization to use TXOP for any reason (for example, if an urgent service that needs to be transmitted immediately arrives), the AP can actively restore / revoke its authorization to use TXOP by transmitting an active restoration frame (i.e., the third frame in the present application).

[0083] Regarding the seventh aspect, in one feasible implementation, the third frame is a block acknowledgement BA frame returned by the first device based on a data frame received from the second device. The BA control field within the BA frame indicates that the first device is actively restoring permission to use TXOP.

[0084] In this embodiment of the present application, the existing improved BA control field within the BA frame is enhanced to indicate that the first device is actively restoring permission to use TXOP, thereby reducing the complexity of implementing the solution.

[0085] Regarding the seventh aspect, in one feasible implementation, the third frame is an aggregated frame, which is obtained by aggregating the fourth frame with the BA frame. The fourth frame indicates that the first device is actively recovering permission to use TXOP. The BA frame is generated by the first device based on data frames received from the second device.

[0086] In this embodiment of the present application, another frame transmitted by aggregating with the BA frame (i.e., a fourth frame) indicates that the first device has actively regained permission to use TXOP. This improves the versatility of implementing the solution.

[0087] With respect to the seventh aspect, in one feasible implementation, the A control field in the fourth frame contains third instruction information. The third instruction information indicates that the first device actively regains permission to use TXOP.

[0088] In this embodiment of the present application, a QoS data frame or QoS null data frame containing an A control field in a fourth frame actively restores permission for the first device to use TXOP, thereby reducing the complexity of implementing the solution.

[0089] With respect to the seventh aspect, in a feasible implementation, the control identifier of the A control field is a third value. The third value indicates that the A control field contains third instruction information.

[0090] With respect to the seventh aspect, in one feasible implementation, the frame type field in the third frame indicates that the third frame is a control frame, and the frame subtype field in the third frame indicates that the third frame is an active recovery frame. An active recovery frame indicates that the first device actively recovers permission to use the transmit opportunity TXOP.

[0091] In this embodiment of the present application, a new type of frame, namely a fourth frame, is designed to instruct the first device to actively regain permission to use TXOP. This improves the versatility of implementing the solution.

[0092] According to the eighth aspect, the present invention provides a method for restoring permission to use a transmit opportunity. This method includes: upon receiving a third frame from a first device, the second device either refrains from transmitting any further data frames or retransmits the data frame k times. The third frame indicates that the first device has actively restored permission to use a transmit opportunity TXOP, where k is an integer greater than 0.

[0093] With respect to the eighth aspect, in one feasible implementation, the third frame is a block acknowledgment BA frame returned by the first device based on a data frame received from the second device. The BA control field within the BA frame indicates that the first device is actively restoring permission to use TXOP.

[0094] With respect to the eighth aspect, in one feasible implementation, the third frame is an aggregate frame, which is obtained by aggregating the fourth frame with the BA frame. The fourth frame indicates that the first device is actively recovering permission to use TXOP. The BA frame is generated by the first device based on data frames received from the second device.

[0095] With respect to the eighth aspect, in one feasible implementation, the A control field in the fourth frame contains third instruction information. The third instruction information instructs the first device to actively regain permission to use TXOP.

[0096] With respect to the eighth aspect, in a feasible implementation, the control identifier of the A control field is a third value. The third value indicates that the A control field contains third instruction information.

[0097] With respect to the eighth aspect, in one feasible implementation, the frame type field of the third frame indicates that the third frame is a control frame, and the frame subtype field of the third frame indicates that the third frame is an active recovery frame. An active recovery frame indicates that the first device will actively recover permission to use the transmit opportunity TXOP.

[0098] According to the ninth aspect, the present invention provides a device for restoring permission to use a transmit opportunity. The device for restoring permission to use a transmit opportunity may be a first device or a chip within the first device, for example, a Wi-Fi chip. The device for restoring permission to use a transmit opportunity includes: a transceiver unit configured to receive a first frame from a second device, the first frame indicating that the second device has stopped using a first time resource, the first time resource being allocated to the second device by the first device from an acquired transmit opportunity TXOP, and the first time resource being allocated to the second device by the first device by using a single-user trigger frame; and a processing unit configured to restore permission to use a TXOP based on the first frame.

[0099] Regarding the ninth aspect, in a feasible implementation, the first time resource is used for the transmission of single-user physical layer protocol data units (PPDUs) on the uplink, or for point-to-point P2P communication, and the single-user trigger frame includes a first field and a second field. The first field indicates the remaining time resource of the TXOP, and the second field indicates the first time resource.

[0100] Regarding the ninth aspect, in a feasible implementation, the first frame carries first instruction information, which indicates that the second device has stopped using the first time resource.

[0101] Regarding the ninth aspect, in one feasible implementation, the first frame further carries second instruction information, which indicates whether the second device requires additional time resources for data transmission.

[0102] With respect to the ninth aspect, in a feasible implementation, the A control field in the first frame contains first instruction information, or the A control field in the first frame contains first instruction information and second instruction information.

[0103] With respect to the ninth aspect, in a feasible implementation, the control identifier of the A control field is a first value. The first value indicates that the A control field contains first instruction information.

[0104] With respect to the ninth aspect, in a feasible implementation, the control identifier of the A control field is a second value. The second value indicates that the A control field is a command and status CAS control field. The first instruction information is carried in the reverse approval RDG subfield within the CAS control field. Alternatively, the first instruction information is carried in the RDG subfield within the CAS control field, and the second instruction information is carried in at least one bit between the fourth and eighth bits within the CAS control field.

[0105] With respect to the ninth aspect, in one feasible implementation, the frame type field in the first frame indicates that the first frame is a control frame, and the frame subtype field in the first frame indicates that the first frame is a time resource return frame. A time resource return frame indicates that the second device has stopped using the first time resource.

[0106] According to the tenth aspect, the present invention provides a device for restoring permission to use a transmit opportunity. The device for restoring permission to use a transmit opportunity may be a second device or a chip within the second device, for example, a Wi-Fi chip. The device for restoring permission to use a transmit opportunity includes: a processing unit configured to determine a first frame, the first frame indicating that the second device has stopped using a first time resource, the first time resource being allocated to the second device by the first device from an acquired transmit opportunity TXOP, and the first time resource being allocated to the second device by the first device using a single-user trigger frame; and a transceiver unit configured to transmit the first frame to the first device.

[0107] With respect to the tenth aspect, in a feasible implementation, the first time resource is used for the transmission of single-user physical layer protocol data units (PPDUs) on the uplink or for point-to-point P2P communication, and the single-user trigger frame includes a first field and a second field. The first field indicates the remaining time resource of the TXOP, and the second field indicates the first time resource.

[0108] With respect to the tenth aspect, in one feasible implementation, the first frame carries first instruction information, which indicates that the second device has stopped using the first time resource.

[0109] With respect to the tenth aspect, in one feasible implementation, the first frame further carries second instruction information, which indicates whether the second device requires additional time resources for data transmission.

[0110] With respect to the tenth aspect, in a certain feasible implementation, the A control field in the first frame contains first instruction information, or the A control field in the first frame contains first instruction information and second instruction information.

[0111] With respect to the tenth aspect, in a certain feasible implementation, the control identifier of the A control field is a first value. The first value indicates that the A control field contains first instruction information.

[0112] With respect to the tenth aspect, in one feasible implementation, the control identifier of the A control field is a second value. The second value indicates that the A control field is a command and status CAS control field. The first instruction information is carried in the reverse approval RDG subfield within the CAS control field. Alternatively, the first instruction information is carried in the RDG subfield within the CAS control field, and the second instruction information is carried in at least one bit in bits 4 through 8 within the CAS control field.

[0113] With respect to the tenth aspect, in one feasible implementation, the frame type field within the first frame indicates that the first frame is a control frame, and the frame subtype field within the first frame indicates that the first frame is a time resource return frame. The time resource return frame indicates that the second device has stopped using the first time resource.

[0114] With respect to the tenth aspect, in a feasible implementation, if the first frame is a Quality of Service (QoS) null data frame, or if the first frame is a time resource return frame, the second device is permitted to send the first frame to the first device if the end of the first frame is after the end of the first time resource and the start of the first frame is earlier than the end of the first time resource.

[0115] According to the eleventh aspect, the present invention provides a device for restoring permission to use a transmit opportunity. The device for restoring permission to use a transmit opportunity may be a first device or a chip within the first device, for example, a Wi-Fi chip. The device for restoring permission to use a transmit opportunity includes: a transceiver unit configured to receive a second frame; and a processing unit configured to restore permission to use a transmit opportunity TXOP if the duration between the end of transmission of the second frame and the end of the first time resource is shorter than a predetermined duration T. The destination address of the second frame is the address of the second device. Alternatively, the sender address of the second frame is the address of the second device, and the second frame is a frame that does not request a response frame. The first time resource is allocated by the first device from the acquired TXOP to the second device.

[0116] With respect to the eleventh aspect, in one feasible implementation, the transceiver unit is further configured to receive a first frame from a second device if the duration between the end of the second frame and the end of the first time resource is greater than T. The first frame indicates that the second device has stopped using the first time resource.

[0117] With respect to the eleventh aspect, in a feasible implementation, the first time resource is used for the transmission of single-user physical layer protocol data units (PPDUs) on the uplink or for point-to-point P2P communication, and the single-user trigger frame includes a first field and a second field. The first field indicates the remaining time resource of the TXOP, and the second field indicates the first time resource.

[0118] With respect to the eleventh aspect, in one feasible implementation, the first frame carries first instruction information, which indicates that the second device has stopped using the first time resource.

[0119] With respect to the eleventh aspect, in one feasible implementation, the first frame further carries second instruction information, which indicates whether the second device requires additional time resources for data transmission.

[0120] With respect to the eleventh aspect, in a certain feasible implementation, the A control field in the first frame contains first instruction information, or the A control field in the first frame contains first instruction information and second instruction information.

[0121] With respect to the eleventh aspect, in a certain feasible implementation, the control identifier of the A control field is a first value. The first value indicates that the A control field contains first instruction information.

[0122] With respect to the eleventh aspect, in a feasible implementation, the control identifier of the A control field is a second value. The second value indicates that the A control field is a command and status CAS control field. The first instruction information is carried in the reverse approval RDG subfield within the CAS control field. Alternatively, the first instruction information is carried in the RDG subfield within the CAS control field, and the second instruction information is carried in at least one bit in bits 4 through 8 within the CAS control field.

[0123] With respect to the eleventh aspect, in one feasible implementation, the frame type field within the first frame indicates that the first frame is a control frame, and the frame subtype field within the first frame indicates that the first frame is a time resource return frame. A time resource return frame indicates that the second device has stopped using the first time resource.

[0124] According to the twelfth aspect, the present invention provides a device for restoring permission to use a transmission opportunity. The device for restoring permission to use a transmission opportunity may be a second device or a chip within the second device, such as a Wi-Fi chip. The device for restoring permission to use a transmission opportunity includes: a transceiver unit configured to receive or transmit a second frame; the second frame is a frame that does not request a response frame; and the second device refrains from transmitting any further PPDUs if the duration between the end of the second frame and the end of the first time resource is shorter than a predetermined duration T.

[0125] With respect to the twelfth aspect, in one feasible implementation, the second device further includes a processing unit. The processing unit is configured to decide to send a first frame to the first device using a transceiver unit if the duration between the end of the second frame and the end of the first time resource is greater than a predetermined duration T. The first frame indicates that the second device has stopped using the first time resource. The first time resource is allocated to the second device by the first device from the acquired TXOP.

[0126] With respect to the twelfth aspect, in a feasible implementation, the first time resource is used for the transmission of single-user physical layer protocol data units (PPDUs) on the uplink or for point-to-point P2P communication, and the single-user trigger frame includes a first field and a second field. The first field indicates the remaining time resource of the TXOP, and the second field indicates the first time resource.

[0127] With respect to the twelfth aspect, in a feasible implementation, the first frame carries first instruction information, which indicates that the second device has stopped using the first time resource.

[0128] With respect to the twelfth aspect, in one feasible implementation, the first frame further carries second instruction information, which indicates whether the second device requires further time resources for data transmission.

[0129] With respect to the twelfth aspect, in a certain feasible implementation, the A control field in the first frame contains first instruction information, or the A control field in the first frame contains first instruction information and second instruction information.

[0130] With respect to the twelfth aspect, in a certain feasible implementation, the control identifier of the A control field is a first value. The first value indicates that the A control field contains first instruction information.

[0131] With respect to the twelfth aspect, in one feasible implementation, the control identifier of the A control field is a second value. The second value indicates that the A control field is a command and status CAS control field.

[0132] The first instruction information is carried in the reverse approval RDG subfield within the CAS control field.

[0133] Alternatively, the first instruction information may be carried in the RDG subfield within the CAS control field, and the second instruction information may be carried in at least one bit in bits 4 through 8 within the CAS control field.

[0134] With respect to the twelfth aspect, in one feasible implementation, the frame type field within the first frame indicates that the first frame is a control frame, and the frame subtype field within the first frame indicates that the first frame is a time resource return frame. The time resource return frame indicates that the second device has stopped using the first time resource.

[0135] With respect to the twelfth aspect, in a feasible implementation, if the first frame is a Quality of Service (QoS) null data frame, or if the first frame is a time resource return frame, the second device is permitted to send the first frame to the first device if the end of the first frame is after the end of the first time resource and the start of the first frame is earlier than the end of the first time resource.

[0136] According to the thirteenth aspect, the present invention provides a device for restoring permission to use a transmission opportunity. The device for restoring permission to use a transmission opportunity may be a first device or a chip within the first device, for example, a Wi-Fi chip. The device for restoring permission to use a transmission opportunity includes: a transceiver unit configured to transmit a second frame, wherein the destination address of the second frame is the address of a second device; and a processing unit configured to restore permission to use a transmission opportunity TXOP if the duration between the end of the second frame and the end of the first time resource is shorter than a predetermined duration T. The first time resource is allocated by the first device from the acquired TXOP to the second device.

[0137] With respect to the 13th aspect, in one feasible implementation, the processing unit is configured to decide to use the transceiver unit to receive the first frame from the second device if the duration between the end of the second frame and the end of the first time resource is greater than T. The first frame indicates that the second device has stopped using the first time resource.

[0138] With respect to the 13th aspect, in a feasible implementation, the first time resource is used for the transmission of single-user physical layer protocol data units (PPDUs) on the uplink or for point-to-point P2P communication, and the single-user trigger frame includes a first field and a second field. The first field indicates the remaining time resource of the TXOP, and the second field indicates the first time resource.

[0139] With respect to the thirteenth aspect, in a feasible implementation, the first frame carries first instruction information, which indicates that the second device has stopped using the first time resource.

[0140] With respect to the thirteenth aspect, in one feasible implementation, the first frame further carries second instruction information, which indicates whether the second device requires additional time resources for data transmission.

[0141] With respect to the 13th aspect, in one feasible implementation, the A control field in the first frame contains first instruction information, or the A control field in the first frame contains first instruction information and second instruction information.

[0142] With respect to the 13th aspect, in a certain feasible implementation, the control identifier of the A control field is a first value. The first value indicates that the A control field contains first instruction information.

[0143] With respect to the 13th aspect, in one feasible implementation, the control identifier of the A control field is a second value. The second value indicates that the A control field is a command and status CAS control field.

[0144] The first instruction information is carried in the reverse approval RDG subfield within the CAS control field.

[0145] Alternatively, the first instruction information may be carried in the RDG subfield within the CAS control field, and the second instruction information may be carried in at least one bit in bits 4 through 8 within the CAS control field.

[0146] With respect to the 13th aspect, in one feasible implementation, the frame type field within the first frame indicates that the first frame is a control frame, and the frame subtype field within the first frame indicates that the first frame is a time resource return frame. A time resource return frame indicates that the second device has stopped using the first time resource.

[0147] According to the fourteenth aspect, the present invention provides a device for restoring permission to use a transmission opportunity. The device for restoring permission to use a transmission opportunity may be a second device or a chip within the second device, for example, a Wi-Fi chip. The device for restoring permission to use a transmission opportunity includes: a transceiver unit configured to receive a second frame from a first device; and a processing unit configured to determine that the second device will not transmit any more PPDUs if the duration between the end of the second frame and the end of the first time resource is shorter than a preset duration T.

[0148] With respect to the 14th aspect, in one feasible implementation, the processing unit is further configured to: use the transceiver unit to send the first frame to the first device if the duration between the end of the second frame and the end of the first time resource is longer than a predetermined duration T. The first frame indicates that the second device has stopped using the first time resource. The first time resource is then allocated to the second device by the first device from the acquired TXOP.

[0149] With respect to the 14th aspect, in a feasible implementation, the first time resource is used for the transmission of Single User Physical Layer Protocol Data Units (PPDUs) on the uplink or for point-to-point P2P communication, and the Single User Trigger Frame includes a first field and a second field. The first field indicates the remaining time resource of the TXOP, and the second field indicates the first time resource.

[0150] With respect to the fourteenth aspect, in a feasible implementation, the first frame carries first instruction information, which indicates that the second device has stopped using the first time resource.

[0151] With respect to the fourteenth aspect, in one feasible implementation, the first frame further carries second instruction information, which indicates whether the second device requires additional time resources for data transmission.

[0152] With respect to the fourteenth aspect, in one feasible implementation, the A control field in the first frame contains first instruction information, or the A control field in the first frame contains first instruction information and second instruction information.

[0153] With respect to the fourteenth aspect, in a certain feasible implementation, the control identifier of the A control field is a first value. The first value indicates that the A control field contains first instruction information.

[0154] With respect to the 14th aspect, in one feasible implementation, the control identifier of the A control field is a second value. The second value indicates that the A control field is a command and status CAS control field.

[0155] The first instruction information is carried in the reverse approval RDG subfield within the CAS control field.

[0156] Alternatively, the first instruction information may be carried in the RDG subfield within the CAS control field, and the second instruction information may be carried in at least one bit in bits 4 through 8 of the CAS control field.

[0157] With respect to the 14th aspect, in one feasible implementation, the frame type field within the first frame indicates that the first frame is a control frame, and the frame subtype field within the first frame indicates that the first frame is a time resource return frame. A time resource return frame indicates that the second device has stopped using the first time resource.

[0158] With respect to the 14th aspect, in a feasible implementation, if the first frame is a Quality of Service (QoS) null data frame, or if the first frame is a time resource return frame, the second device is permitted to send the first frame to the first device if the end of the first frame is after the end of the first time resource and the start of the first frame is earlier than the end of the first time resource.

[0159] According to the fifteenth aspect, the present invention provides a device for restoring permission to use a transmit opportunity. The device for restoring permission to use a transmit opportunity may be a first device or a chip within the first device, for example, a Wi-Fi chip. The device for restoring permission to use a transmit opportunity includes: a processing unit configured to determine a third frame; and a transceiver unit configured to transmit the third frame to a second device. The third frame instructs the first device to actively restore permission to use a transmit opportunity TXOP.

[0160] With respect to the 15th aspect, in one feasible implementation, the third frame is a block acknowledgement BA frame returned by the first device based on a data frame received from the second device. The BA control field within the BA frame indicates that the first device is actively restoring permission to use TXOP.

[0161] With respect to the 15th aspect, in one feasible implementation, the third frame is an aggregated frame, which is obtained by aggregating the fourth frame with the BA frame. The fourth frame instructs the first device to actively regain permission to use TXOP. The BA frame is generated by the first device based on data frames received from the second device.

[0162] With respect to the 15th aspect, in one feasible implementation, the A control field in the fourth frame contains third instruction information. The third instruction information instructs the first device to actively regain permission to use TXOP.

[0163] With respect to the 15th aspect, in a certain feasible implementation, the control identifier of the A control field is a third value. The third value indicates that the A control field contains third instruction information.

[0164] With respect to the 15th aspect, in one feasible implementation, the frame type field in the third frame indicates that the third frame is a control frame, and the frame subtype field in the third frame indicates that the third frame is an active recovery frame. An active recovery frame indicates that the first device will actively recover permission to use the transmit opportunity TXOP.

[0165] According to the sixteenth aspect, the present invention provides a device for restoring permission to use a transmit opportunity. The device for restoring permission to use a transmit opportunity may be a second device or a chip within the second device, such as a Wi-Fi chip. The device for restoring permission to use a transmit opportunity includes: a processing unit configured to determine, upon receiving a third frame from the first device, that the second device will not transmit any more data frames using a transceiver unit, or will use the transceiver unit to retransmit the data frame k times. The third frame indicates that the first device has actively restored permission to use a transmit opportunity TXOP, where k is an integer greater than 0.

[0166] With respect to the sixteenth aspect, in one feasible implementation, the third frame is a block acknowledgment BA frame returned by the first device based on a data frame received from the second device. The BA control field within the BA frame indicates that the first device is actively restoring permission to use TXOP.

[0167] With respect to the sixteenth aspect, in one feasible implementation, the third frame is an aggregate frame, which is obtained by aggregating the fourth frame with the BA frame. The fourth frame instructs the first device to actively regain permission to use TXOP. The BA frame is generated by the first device based on data frames received from the second device.

[0168] With respect to the sixteenth aspect, in one feasible implementation, the A control field in the fourth frame contains third instruction information, which indicates that the first device actively regains permission to use TXOP.

[0169] With respect to the sixteenth aspect, in a certain feasible implementation, the control identifier of the A control field is a third value. The third value indicates that the A control field contains third instruction information.

[0170] With respect to the sixteenth aspect, in one feasible implementation, the frame type field of the third frame indicates that the third frame is a control frame, and the frame subtype field of the third frame indicates that the third frame is an active recovery frame. An active recovery frame indicates that the first device actively recovers permission to use the transmit opportunity TXOP.

[0171] According to the 17th aspect, the present application provides a communication device. The communication device is specifically a first device in the first, third, fifth, or seventh aspect, and includes a processor and a transceiver. The processor is configured to support the first device to perform the corresponding function in the manner described above. The transceiver is configured to support the communication of the first device to receive or transmit information, frames, or instructions in the manner described above. The first device may further include memory. The memory is configured to be coupled to the processor and stores program instructions and data necessary for the first device.

[0172] According to the eighteenth aspect, the present application provides a communication device, which is specifically a second device in the second, fourth, sixth, or eighth aspect, and includes a processor and a transceiver. The processor is configured to support the second device to perform the corresponding function in the above method. The transceiver is configured to support communication of the second device to receive or transmit information, frames, or instructions in the above method. The second device may further include memory, which is configured to be coupled to the processor and stores program instructions and data necessary for the second device.

[0173] According to the 19th aspect, the present application provides a device which is implemented in the form of a chip product and includes an input / output interface and processing circuitry. The device is a chip in a first device according to the first, third, fifth, or seventh aspect. The input / output interface is configured to receive or transmit information, frames, or instructions in the manner described above. The processing circuitry is configured to support the first device in performing the corresponding functions in the manner described above.

[0174] According to the 20th aspect, the present application provides a device which is implemented in the form of a chip product and includes an input / output interface and processing circuitry. The device is a chip in a second device according to the second, fourth, sixth, or eighth aspect. The input / output interface is configured to receive or transmit information, frames, or instructions in the manner described above. The processing circuitry is configured to support the second device in performing the corresponding functions in the manner described above.

[0175] According to the 21st aspect, the present application provides a computer-readable storage medium that stores program instructions, and when the program instructions are executed on a computer, the computer is enabled to perform a method to recover permission to use a transmission opportunity according to the first, third, fifth, or seventh aspect. Alternatively, when the program instructions are executed on a computer, the computer is enabled to perform a method to recover permission to use a transmission opportunity according to the second, fourth, sixth, or eighth aspect.

[0176] According to Aspect 22, the present application provides a computer program product comprising program instructions. When the computer program product is running on a computer, the computer is enabled to perform a method to restore permission to use a transmission opportunity according to Aspect 1, Aspect 3, Aspect 5, or Aspect 7. Alternatively, when the computer program product is running on a computer, the computer is enabled to perform a method to restore permission to use a transmission opportunity according to Aspect 2, Aspect 4, Aspect 6, or Aspect 8.

[0177] According to the 23rd aspect, one embodiment of the present application provides a wireless communication system. The system includes a first device according to the 9th, 11th, 13th, or 15th aspect, and a second device according to the 10th, 12th, 14th, or 16th aspect.

[0178] According to embodiments of the present invention, a first frame may indicate that a second device has stopped using the allocated time resource (first time resource). Therefore, the first device may, based on the instructions in the first frame, revoke / recover permission to use TXOP in advance. This can improve channel resource utilization and the reliability of recovering permission to use TXOP. [Brief explanation of the drawing]

[0179] [Figure 1a] This is a schematic diagram of the communication system architecture according to the present invention.

[0180] [Figure 1b] This is a schematic diagram of the structure of an access point according to one embodiment of the present invention.

[0181] [Figure 1c] This is a schematic diagram of the structure of an STA with a single antenna / radio frequency.

[0182] [Figure 2a]This is a schematic diagram illustrating the application of a single-user trigger frame to a P2P scenario.

[0183] [Figure 2b] This is a schematic diagram of applying single-user trigger frames to a UL transmission scenario.

[0184] [Figure 2c] This is a schematic diagram showing the remaining duration.

[0185] [Figure 3] This is a schematic flowchart of a method for restoring permission to use a transmission opportunity according to one embodiment of the present invention.

[0186] [Figure 4] This is a schematic diagram of the structure of a first frame according to one embodiment of the present invention.

[0187] [Figure 5] This is a schematic diagram of an application scenario for restoring permission to use TXOP in a UL scenario according to one embodiment of the present application.

[0188] [Figure 6] This is a schematic diagram of an application scenario for restoring permission to use TXOP in a P2P scenario according to one embodiment of the present invention.

[0189] [Figure 7] This is another schematic diagram of the structure of the first frame according to one embodiment of the present invention.

[0190] [Figure 8] This is another schematic diagram of the structure of the first frame according to one embodiment of the present invention.

[0191] [Figure 9] This is a schematic diagram of another application scenario that restores permission to use TXOP in a UL scenario according to one embodiment of the present application.

[0192] [Figure 10] This is a schematic diagram of another application scenario for restoring permission to use TXOP in a P2P scenario according to one embodiment of the present invention.

[0193] [Figure 11a] This is another schematic diagram of the structure of the first frame according to one embodiment of the present invention.

[0194] [Figure 11b] This is another schematic diagram of the structure of the first frame according to one embodiment of the present invention.

[0195] [Figure 12] This is a schematic diagram of the structure of a frame control field according to one embodiment of the present invention.

[0196] [Figure 13] This is a schematic diagram of a UL scenario according to one embodiment of the present invention in which cross-boundary transmission of SU END frames is permitted.

[0197] [Figure 14] This is a schematic diagram of a P2P scenario according to one embodiment of the present invention in which cross-boundary transmission of SU END frames is permitted.

[0198] [Figure 15] This is a schematic diagram of another application scenario in which permission to use TXOP is restored in a P2P scenario according to one embodiment of the present invention.

[0199] [Figure 16] This is another schematic flowchart of a method for restoring permission to use a transmission opportunity according to one embodiment of the present invention.

[0200] [Figure 17]This is a schematic diagram of a scenario in the P2P scenario according to the present application for restoring permission to use TXOP based on a pre-set duration T.

[0201] [Figure 18] This is another schematic flowchart of a method for restoring permission to use a transmission opportunity according to one embodiment of the present invention.

[0202] [Figure 19] This is a schematic diagram of a scenario in the UL scenario of this application in which permission to use TXOP is restored based on a pre-set duration T.

[0203] [Figure 20] This is another schematic flowchart of a method for restoring permission to use a transmission opportunity according to one embodiment of the present invention.

[0204] [Figure 21] This is a schematic diagram of the structure of an improved BA frame according to one embodiment of the present invention.

[0205] [Figure 22] This is a schematic diagram of an application scenario in which the first device actively recovers permission to use TXOP according to the present invention.

[0206] [Figure 23] This is another schematic diagram of an application scenario in which the first device actively recovers permission to use TXOP according to the present application.

[0207] [Figure 24] This is another schematic diagram of an application scenario in which the first device actively recovers permission to use TXOP according to the present application.

[0208] [Figure 25] This is a schematic diagram of the structure of a device 1 for restoring permission to use a transmission opportunity according to one embodiment of the present invention.

[0209] [Figure 26] This is a schematic diagram of the structure of a communication device 1000 according to one embodiment of the present invention. [Modes for carrying out the invention]

[0210] The following describes the technical solutions in the embodiments of this application with reference to the accompanying drawings.

[0211] In this description, unless otherwise specified, " / " means "or". For example, A / B may represent A or B. The term "and / or" in this specification merely describes a relationship between related objects, indicating that there may be three possible relationships. For example, A and / or B may represent the following three cases: only A exists, both A and B exist, or only B exists. Also, "at least one" means one or more, and "multiple" means two or more. 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 a clear distinction.

[0212] In this application, words such as “example” or “for example” indicate that an example, illustration, or explanation is being provided. Not all embodiments or design schemes described as “example” or “for example” in this application should be described as superior to or having greater advantages over other embodiments or design schemes. More precisely, the use of the words “example” or “for example” is intended to present the relevant concepts in a specific manner.

[0213] The technical solutions provided herein can be applied to a variety of communication systems, such as systems using the IEEE 802.11 standard. For example, the IEEE 802.11 standard includes, but is not limited to, the 802.11ax standard, the 802.11be standard, or the next-generation 802.11 standard. Scenarios to which the technical solutions of this application apply include communication between an AP and one or more STAs, communication between APs, and communication between STAs. For example, Figure 1a is a schematic diagram of the architecture of a communication system according to this application. As shown in Figure 1a, the communication system may include one AP and two STAs (for example, STA1 and STA2 in Figure 1a). The AP may communicate with STA1, or the AP may further communicate with STA2.

[0214] In this application, an access point (AP) is a device having wireless communication capabilities and supporting communication based on a wireless local area network (WLAN) protocol. The access point may have the ability to communicate with other devices within the WLAN network (e.g., a station or other access point). Of course, the access point may also have the ability to communicate with yet another device. In a WLAN system, an access point may be referred to as an access point station (AP STA). The device having wireless communication capabilities may be an entire device, or a chip or processing system mounted on the entire device. A device on which the chip or processing system is located can implement the methods and functions of the embodiments of this application under the control of the chip or processing system. In the embodiments of this application, the AP is a device that provides services for an STA and can support 802.11 series protocols. For example, the AP may be a communication entity, such as a communication server, router, switch, or bridge. The AP may include macro base stations, micro base stations, relay stations, etc., in various forms. Of course, the AP may alternatively be a chip or processing system within various forms of these devices to implement the methods and functions of the embodiments of this application.

[0215] In this application, a station (STA) is a device having wireless communication capabilities, supporting communication based on the WLAN protocol, and having the ability to communicate with another station or access point within a WLAN network. In a WLAN system, a station may also be referred to as a non-access point station (non-AP STA). For example, an STA is any user communication device that allows a user to communicate with an AP and further with the WLAN. The device having wireless communication capabilities may be the entire device, or a chip or processing system mounted on the entire device. A device on which a chip or processing system is located can implement the methods and functions of the embodiments of this application under the control of the chip or processing system. For example, an STA may be a user device that can connect to the Internet, such as a tablet computer, desktop computer, laptop computer, notebook computer, ultra-mobile personal computer (UMPC), handheld computer, netbook, personal digital assistant (PDA), or mobile phone. Alternatively, STA may be an Internet of Things node in the Internet of Things, an in-vehicle communication device in the Internet of Vehicles, an entertainment device, a game device or system, a global positioning system device, etc. Alternatively, STA may be a chip and processing system in the aforementioned terminal.

[0216] WLAN systems can provide high-speed and low-latency transmission. With the continuous evolution of WLAN application scenarios, WLAN systems will be applied to more scenarios and industries, including the Internet of Things industry, the Internet of Vehicles industry, the banking industry, corporate offices, stadium exhibition halls, concert halls, hotel rooms, dormitories, hospital wards, classrooms, supermarkets, squares, streets, production workshops, warehouses, and more. Of course, devices supporting WLAN communication (e.g., access points or stations) may include sensor nodes in smart cities (e.g., smart water meters, smart electricity meters, or smart air sensing nodes), smart devices in smart homes (e.g., smart cameras, projectors, displays, televisions, stereos, refrigerators, washing machines, etc.), nodes in the Internet of Things, entertainment terminals (e.g., augmented reality (AR), virtual reality (VR), or other wearable devices), smart devices in smart offices (e.g., printers, projectors, speakers, or stereos), Internet of Vehicle devices in the Internet of Vehicles, infrastructure in everyday life scenarios (e.g., vending machines, self-service navigation stations in supermarkets, self-service checkout machines, or self-service ordering machines), devices in large sports and music venues, and the like. The specific forms of STA and AP are not limited to the embodiments of this application and are merely examples for the purposes of this description.

[0217] It should be understood that the 802.11 standard focuses on the physical layer (PHY) and media access control (MAC) layers. For example, Figure 1b is a schematic diagram of the structure of an access point according to one embodiment of the present application. The AP may have multiple antennas / radio frequencies or a single antenna / radio frequency. The antenna / radio frequency is used to transmit and receive data packets. In some implementations, the antenna or radio frequency portion of the AP may be separated, i.e., located remotely from the main body of the AP. In Figure 1b, the AP may include physical layer processing circuitry and media access control processing circuitry. The physical layer processing circuitry may be configured to process physical layer signals, and the MAC layer processing circuitry may be configured to process MAC layer signals. As another example, Figure 1c is a schematic diagram of the structure of a station according to one embodiment of the present application. Figure 1c is a schematic diagram of the structure of an STA with a single antenna / radio frequency. In practical scenarios, the STA may alternatively have multiple antennas / radio frequencies, and may be a device with more than two antennas. The antenna / radio frequency is used to transmit and receive data packets. In some implementations, the antenna or radio frequency portion of the STA may be separated, in other words, located remotely from the main body of the STA. In Figure 1c, the STA may include a PHY processing circuit and a MAC processing circuit. The physical layer processing circuit may be configured to process physical layer signals, and the MAC layer processing circuit may be configured to process MAC layer signals.

[0218] To better understand the technical solutions provided in this application, the following briefly describes application scenarios for the method of restoring permission to use the transmission opportunity provided in this embodiment of the application.

[0219] The method for restoring permission to use transmission opportunities provided in this embodiment of the present application may be applied to point-to-point (or peer-to-peer, P2P) communication scenarios, uplink (UL) transmission scenarios, and the like, but is not limited herein. The data transmission formats used in the P2P and UL scenarios in this embodiment of the present application include, but are not limited herein, SU PPDU, etc.

[0220] It should be understood that the trigger frame in the current IEEE 802.11ax standard is designed for multiple users to simultaneously transmit uplink TB PPDUs. Therefore, the current trigger frame needs to show information such as the Modulation and Coding Scheme (MCS), Resource Unit (RU), and Transmit Power. Since APs typically have stronger channel access capabilities, the next-generation IEEE 802.11be standard needs to support AP-triggered SU PPDUs. Currently, to implement AP-triggered SU PPDUs, the AP may send a single-user trigger frame to allocate a portion of the time resources in the TXOP to the associated STA (for simplicity, hereafter referred to briefly as the designated STA or target STA). The designated STA then communicates with another STA or AP on the allocated time resources. The communication between the designated STA and another STA may be understood as P2P communication or P2P transmission, and the communication between the designated STA and the AP may be understood as UL communication or UL transmission.

[0221] For example, Figure 2a is a schematic diagram of applying a single-user trigger frame to a P2P scenario. As shown in Figure 2a, after obtaining a TXOP, the AP may use a single-user trigger frame (e.g., a modified multi-user request to send (mMU-RTS) frame in Figure 2a) to allocate some or all of the remaining time resources in the TXOP (e.g., the first time resource in Figure 2a) to a designated STA (e.g., STA1 in Figure 2a). In the following embodiments of the Application, the first time resource may be referred to as a single-user service period (SU SP), but is not limited thereto. The mMU-RTS frame may carry information about STA1, the remaining time resources in the TXOP, and the duration of the first time resource allocated to STA1. Thus, in the allocated first time resource, STA1 may send an SU PPDU to STA2, and STA2 may send a block acknowledgement (BA) frame for the SU PPDU to STA1. In this embodiment of the present application, it is readily apparent that the start time of the first time resource is not earlier than the start time of TXOP, and the end time of the first time resource is not later than the end time of TXOP. In other words, the start time of the first time resource is at or after the start time of TXOP, and the end time of the first time resource is at or after the end time of TXOP.

[0222] Optionally, the mMU-RTS frame may carry further information, such as whether the designated STA needs to respond to a Clear to Send (CTS) frame. See, for example, Figure 2a. If, after STA1 receives an mMU-RTS frame sent by AP, STA1 parses the mMU-RTS frame and determines that AP has allocated STA1 a first time resource and is requesting STA1 to respond to a CTS frame before sending a SU PPDU, then STA1 can first send a CTS frame in the allocated first time resource, send a SU PPDU to STA2, and then receive a BA frame of the SU PPDU returned to STA1 by STA2. In a P2P scenario, it should be understood that AP can only regain permission to use TXOP after the end of the first time resource. The AP regaining permission to use TXOP may be understood as the AP being able to send a PPDU (as shown in Figure 2a), allocate a PPDU to another STA, etc., during the time period from the end of the first time resource to the end of TXOP (Ts in Figure 2a). This will be determined specifically based on the actual application scenario and is not limited thereto.

[0223] For example, Figure 2b is a schematic diagram of applying a single-user trigger frame to a UL transmission scenario. As shown in Figure 2b, after receiving a TXOP, the AP can use a single-user trigger frame (e.g., an mMU-RTS frame in Figure 2b) to allocate some or all of the remaining time resources in the TXOP (e.g., the first time resource in Figure 2b) to a designated STA (e.g., STA1 in Figure 2b). The mMU-RTS frame may carry information about STA1, the remaining time resources in the TXOP, and the duration of the first time resource allocated to STA1. Thus, with the allocated first time resource, STA1 may send a SU PPDU to the AP, and the AP may send a BA frame of the SU PPDU to STA1. Optionally, if the mMU-RTS frame further carries information that the designated STA needs to respond to a CTS frame, after receiving the MU-RTS frame, STA1 must first send one CTS frame and then send a SU PPDU to the AP. In a UL transmission scenario, it should be understood that the AP can only regain permission to use TXOP after the end of the first time resource. See, for example, Figure 2b. The AP sends a PPDU at the end of the first time resource.

[0224] It should be understood that if the duration of the first time resource allocated by the AP to a designated STA is long, and the designated STA has used the first time resource for a certain period and completed the necessary transmissions, the designated STA will not use the first time resource for the remaining period. For example, Figure 2c is a schematic diagram of the remaining duration. As shown in Figure 2c, if the duration of the first time resource allocated by the AP to a designated STA (e.g., STA1 in Figure 2c) is long, and STA1 has completed all transmissions at time t1 in Figure 2c, the designated STA will not use the first time resource for the remaining period (e.g., the period from t1 to t2 in Figure 2c). Optionally, if the duration of the first time resource allocated by the AP to a designated STA is short, and the designated STA has used the first time resource for a certain period and has not completed the necessary transmissions, but the remaining duration of the first time resource is not sufficient to transmit a complete SU PPDU, the designated STA will not use the first time resource for the remaining period. In any case where the first time resource has a remaining duration, it may be understood that the remaining duration results in wasted channel resources, and that during the remaining duration, another STA may be allowed to obtain permission to use the channel through competition. However, the AP cannot recover permission to use TXOP. Therefore, one embodiment of the present application provides a method for recovering permission to use a transmit opportunity. In this method, permission to use a transmit opportunity can be recovered in advance, improving channel resource utilization and the reliability of recovering permission to use TXOP.

[0225] The technical solutions provided in this application will be described in detail below with reference to further accompanying drawings.

[0226] In this application, the first device may be an AP, and the second device may be a non-access point station (i.e., a non-AP STA), or an access point AP. For the sake of simplicity, the first and second devices below are used as examples for the purposes of this application.

[0227] Furthermore, it can be understood that both the first and second devices in this application support the 802.11be protocol (or Wi-Fi 7, also known as the EHT protocol) and may also support other WLAN communication protocols, such as 802.11ax and 802.11ac protocols. It should be understood that the first and second devices in this application may further support next-generation protocols of the 802.11be protocol. In other words, the methods provided in this application are applicable to the 802.11be protocol and next-generation protocols of the 802.11be protocol.

[0228] One embodiment of the present invention provides a method for restoring permission to use a transmission opportunity. A first device may restore / revoke permission to use a TXOP by receiving a first frame transmitted by a second device that indicates it is returning a TXOP.

[0229] Specifically, Figure 3 is a schematic flowchart of a method for restoring permission to use a transmission opportunity according to one embodiment of the present invention. As shown in Figure 3, the method for restoring permission to use a transmission opportunity includes the following steps:

[0230] S101: The first device receives the first frame from the second device.

[0231] In some feasible implementations, the first device may receive a first frame from the second device. The first frame indicates that the second device has stopped using the first time resource. It should be understood that the first time resource may be allocated from the acquired TXOP to the second device by the first device using a single-user trigger frame. Specifically, after acquiring the TXOP, the first device may immediately use a single-user trigger frame to allocate some or all of the time resource in the TXOP to the second device. Alternatively, after acquiring the TXOP, the first device may use some of the time resource and then use a single-user trigger frame to allocate some or all of the remaining time resource in the TXOP to the second device.

[0232] Generally, after a first time resource is allocated to a second device, the second device can use the first time resource to perform single-user PPDU transmission or P2P communication on the uplink. A single-user trigger frame may include a first field and a second field. The first field indicates the remaining time resource of the TXOP. Specifically, the first field is a duration field, and the second field indicates the first time resource. That is, a single-user trigger frame may carry information indicating the remaining duration of the TXOP and information indicating the first time resource. The single-user trigger frame in this embodiment of the Application may be based on or designed using a multi-user (MU) request to send (RTS) frame (for simplicity of explanation, in this Application, the single-user trigger frame will be referred to as a modified or improved MU-RTS frame or mMu-RTS frame below). Alternatively, the single-user trigger frame may be a new type of trigger frame. This will be determined specifically based on actual application scenarios and is not limited to this application.

[0233] In some feasible implementations, the first frame received by the first device from the second device may carry first instruction information. The first instruction information indicates that the second device has stopped using the first time resource. In a UL scenario, the first frame may be a quality of service data (QoS data) frame or a quality of service null data (QoS null data) frame. In a P2P scenario, the first frame may be a QoS null data frame. Both QoS data frames and QoS null data frames are MAC layer frames (i.e., MAC frames). When encapsulated at the physical layer, both QoS data frames and QoS null data frames must be encapsulated in an SU PPDU for transmission. A QoS null data frame may be understood as a special type of QoS data frame; that is, a QoS null data frame is a QoS data frame that does not carry service data. Service data may be, and is not limited to, voice data, video data, file data, etc. It should be understood that both QoS data frames and QoS null data frames contain an A control field. The control ID field within the A control field indicates the control field type of the A control field. For example, if the control identifier of the A control field is 6 (i.e., the second value in this application), it indicates that the A control field is specifically a CAS control field.

[0234] In some feasible implementations, when the A control field is a CAS control field (i.e., when the control ID field in the A control field = 6), the meaning of the value of the reverse grant (RDG) / More PPDU (RDG / More PPDU) subfield in the improved CAS control field may indicate that the second device has stopped using the first time resource. That is, when the A control field is a CAS control field, the first instruction information is the RDG / More PPDU subfield in the CAS control field. "Improved" in this application can be understood as the meaning of the RDG / More PPDU value in the original standard protocol (i.e., the IEEE 802.11ax standard protocol) being modified / adjusted so that the RDG / More PPDU subfield can indicate that the second device has stopped using the first time resource. In this embodiment of this application, the "RDG / More PPDU subfield" may alternatively be described as the "RDG subfield" for brevity.

[0235] For clarity, Figure 4 shows a schematic diagram of the structure of a first frame according to one embodiment of the present invention. The first frame is a QoS data frame within an improved CAS control field. As shown in Figure 4, the QoS data frame may include a Frame Control field, a Duration field, an Address 1 field, an Address 2 field, an Address 3 field, a Sequence Control field, an Address 4 field, a Quality of Service (QoS Control) field, an A-Control field, a Frame Body field, and a frame check sequence (FCS) field. The A-Control field contains 30 bits and may carry one or more control field types. Each control field type includes a 4-bit Control ID field and a control information field of a specific length. In other words, one control ID may represent one control field type, and the field length of the control information field corresponding to each control ID is fixed, although control information fields corresponding to different control IDs may have different lengths. For example, as shown in Figure 4, when control identifier = 6, it indicates that control field A is a CAS control field. Specifically, in a CAS control field, the field length of the control information field is 8 bits. In the control information field within a CAS control field, the first bit indicates the Access Type Constraint (AC Constraint) subfield, the second bit indicates the Reverse Approval / Further PPDU (RDG / More PPDU) subfield, the third bit indicates the Parameter-Based Spatial Reuse Transmission (PSRT PPDU) subfield, and the fourth through eighth bits indicate the Reserved field.

[0236] In the IEEE 802.11ax standard, the values ​​of the RDG / further PPDU subfields within the CAS control field and their associated meanings are shown in Table 1. [Table 1]

[0237] As shown in Table 1, the first column represents the value of the RDG / Further PPDU subfield, the second column represents the identity / role of the STA sending the PPDU containing the RGB / Further PPDU subfield (i.e., the role of the sending STA), and the third column represents the specific meaning of those values. As shown in Table 1, if the role of the sending STA is not an RD responder, a value of 0 in the RGB / Further PPDU subfield indicates that there is no reverse approval. If the role of the sending STA is an RD responder, a value of 0 in the RGB / Further PPDU subfield indicates that the PPDU carrying the frame is the last transmission by the RD responder. Correspondingly, if the role of the sending STA is an RD initiator, a value of 1 in the RGB / Further PPDU subfield indicates that reverse approval exists. If the role of the sending STA is an RD responder, a value of 1 in the RGB / Further PPDU subfield indicates that another PPDU follows the PPDU carrying the frame.

[0238] In this application, it may be understood that the meaning of the values ​​of the RGB / further PPDU subfields in the original CAS control field needs to be modified / improved based on Table 1 in order to allow the RGB / further PPDU subfields in the improved CAS control field to instruct the second device to stop using the first time resource. The values ​​of the RGB / further PPDU subfields in the improved CAS control field and their associated meanings are shown in Table 2. [Table 2]

[0239] As shown in Table 2, the first column represents the value of the RGB / Further PPDU subfield, the second column represents the identity / role of the STA sending the PPDU containing the RGB / Further PPDU subfield (i.e., the role of the sending STA), and the third column represents the specific meaning of those values. As shown in Table 2, the meaning of the RGB / Further PPDU subfield values ​​in the Enhanced CAS Control Fields is as follows: If the role of the sending STA is neither an RD responder nor a target STA in one SU SP, a value of 0 in the RGB / Further PPDU subfield indicates that there is no reverse authorization. If the role of the sending STA is an RD responder, a value of 0 in the RGB / Further PPDU subfield indicates that the PPDU carrying the frame is the last transmission by the RD responder. If the role of the sending STA is a target STA in one SU SP, a value of 0 in the RGB / Further PPDU subfield indicates that the PPDU carrying the frame is the last transmission by the target STA in the SU SP. Correspondingly, if the transmitting STA's role is RD initiator, a value of 1 in the RGB / Further PPDU subfield indicates the presence of reverse authorization. If the transmitting STA's role is RD responder or target STA in one SU SP, a value of 1 in the RGB / Further PPDU subfield indicates that another PPDU follows the PPDU carrying the frame.

[0240] "The PPDU carrying the frame is the last transmission by the target STA in the SU SP" should be understood as the target STA (i.e., the second device in this application) ceasing to use the first time resource. The first device is the assignor of the SU SP (i.e., the first time resource in this application), and specifically, the first device may assign the first time resource to the second device from an acquired transmission opportunity TXOP using a single-user trigger frame. Thus, the first device knows which specific device can use the first time resource. When the first device receives the first frame in the first time resource, it can be understood that the first device parses the first frame if it determines that the sender address of the first frame is that of the second device, and that the second device is the second device to which the first time resource is assigned (i.e., the second device is the designated STA / target STA). If the first device, through parsing, knows that the value of the RDG subfield in the CAS control field within the first frame is 0, it indicates that the PPDU carrying the frame is the last transmission by the target STA in the SU SP. In other words, the first device can determine that the second device has stopped using the first time resource.

[0241] Optionally, to allow the RGB / Further PPDU subfield in the improved CAS control field to indicate that the second device has stopped using the first time resource, the values ​​of the RGB / Further PPDU subfield in the improved CAS control field and their associated meanings are shown in Table 3. [Table 3]

[0242] As shown in Table 3, the first column represents the value of the RGB / Further PPDU subfield, the second column represents the identity / role of the STA sending the PPDU containing the RGB / Further PPDU subfield (i.e., the role of the sending STA), and the third column represents the specific meaning of the value. As shown in Table 3, the meaning of the value of the RGB / Further PPDU subfield in the Enhanced CAS Control Field is as follows: If the role of the sending STA is neither an RD responder nor a target STA in one SU SP, a value of 0 in the RGB / Further PPDU subfield indicates that there is no reverse approval. If the role of the sending STA is an RD responder, a value of 0 in the RGB / Further PPDU subfield indicates that the PPDU carrying the frame is the last transmission by the RD responder. If the role of the sending STA is a target STA in one SU SP, a value of 0 in the RGB / Further PPDU subfield indicates that another PPDU follows the PPDU carrying the frame. Correspondingly, if the role of the sending STA is an RD initiator, a value of 1 in the RGB / Further PPDU subfield indicates that reverse approval exists. If the transmitting STA's role is an RD responder, setting the value of the RGB / Further PPDU subfield to 1 indicates that another PPDU follows the PPDU carrying the frame. If the transmitting STA's role is a target STA within a single SU SP, setting the value of the RGB / Further PPDU subfield to 1 indicates that the PPDU carrying the frame is the last transmission by the target STA within the SU SP.

[0243] The statement "the PPDU carrying the frame is the last transmission by the target STA in the SU SP" should be understood as the target STA (i.e., the second device in this application) ceasing to use the first time resource. Specifically, when the second device receives the first frame from the first device, if the second device determines that the first device is the target STA, the second device parses the first frame. If, through parsing, the first device knows that the value of the RDG subfield in the CAS control field within the first frame is 1, it indicates that the PPDU carrying the frame is the last transmission by the target STA in the SU SP. In other words, the first device can determine that the second device has ceased to use the first time resource. Thus, the first device may regain permission to use the TXOP.

[0244] For clarity, Figure 5 shows a schematic diagram of an application scenario in which permission to use TXOP in a UL scenario is restored according to one embodiment of the present invention. As shown in Figure 5, in the UL scenario, for the process from when the first device (e.g., AP in Figure 5) transmits an mMU-RTS frame to when the second device (e.g., STA1 in Figure 5) transmits an SU PPDU in the first time resource (e.g., SU SP in Figure 5) to the SU PPDU receiver (e.g., AP in Figure 5), please refer to the process described in Figure 2b. Details will not be described again here. When STA1 transmits the last SU PPDU to AP in SU SP and the enhanced CAS control field is carried in the SU PPDU, the RDG subfield (i.e., RGB / further PPDU subfield) in the CAS control field within the SU PPDU may indicate to AP that the current SU PPDU is the last SU PPDU transmitted in SU SP. Therefore, after receiving a SU PPDU carrying the improved CAS control field, the AP may respond to STA1 with a BA frame when or after the Short Inter-frame Space (SIFS) has elapsed, and then regain permission to use TXOP when the SIFS has elapsed. If the SU PPDU carrying the improved CAS control field does not require the AP to respond with a BA frame, it can be understood that the AP may regain permission to use TXOP when the SIFS has elapsed after receiving the SU PPDU carrying the improved CAS control field (for example, the AP sends the PPDU in Figure 5). The final SU PPDU is a SU PPDU encapsulated with a QoS data frame.

[0245] For clarity, Figure 6 shows a schematic diagram of an application scenario in which permission to use TXOP in a P2P scenario according to one embodiment of the present invention is restored. As shown in Figure 6, in the P2P scenario, for the process from when the first device (e.g., AP in Figure 6) transmits an mMU-RTS frame to when the second device (e.g., STA1 in Figure 6) transmits an SU PPDU at the first resource (e.g., SU SP in Figure 6) to the SU PPDU receiver (e.g., STA2 in Figure 6), please refer to the process described in Figure 2a. Further details will not be described again here. When STA1 transmits the last SU PPDU at SU SP to STA2, if STA1 has successfully received the BA frame transmitted by STA2, STA1 may, after SIFS has elapsed since receiving the BA frame, transmit a QoS null data frame carrying an improved CAS control field to the AP to indicate that STA1 has stopped using the SU SP. It should be understood that the QoS null data frame is also transmitted in SU PPDU format. Therefore, after receiving a QoS null data frame and an encapsulated SU PPDU in the improved CAS control field, the AP may regain permission to use TXOP as soon as SIFS has elapsed (for example, the AP sends the PPDU in Figure 6).

[0246] Optionally, in some feasible implementations, if the first frame is a QoS data frame, or if the first frame is a QoS null data frame, a new A-control field may be further designed to indicate that the second device has stopped using the first time resource. For example, Figure 7 shows a schematic diagram of the structure of the first frame according to one embodiment of the present application. As shown in Figure 7, the QoS data frame may include a Frame Control field, a Duration field, an Address 1 field, an Address 2 field, an Address 3 field, a Sequence Control field, an Address 4 field, a QoS Control field, an A-Control field, a Frame Body field, and a Frame Check Sequence (FCS) field. The A-control field contains 30 bits and may carry one or more control field types. Each control field type includes a 4-bit Control ID field and a control information field of a specific length. In other words, one control ID may represent one control field type, and the field length of the control information field corresponding to each control ID is fixed, although control information fields corresponding to different control IDs may have different lengths. In this embodiment of the present application, it can be understood that when a new A control field is designed, the length of the control information field within the new A control field may be designed to be 8 bits. Of the 8 bits contained in the control information field, at least one bit may be set to indicate a single-user end (SU END) subfield, and another bit, different from the single-user end subfield, indicates a reserved subfield.As shown in Figure 7, in the 8 bits included in the control information field, the first bit may be used to indicate a single-user end (SU END) subfield, and the second through eighth bits may be used to indicate reserved subfields. When the value of the control identifier is the first value (for example, control identifier = 7), the first value indicates that the A control field contains the first instruction information. It may be understood that the control identifier in a new A control field may be set to a different identifier not used in the standard protocol. For example, the control identifier in a new A control field may be further set to 8 to indicate that the control field is a new type of A control field. This is specifically determined based on the actual application scenario and is not limited thereto. Optionally, when a new A control field is designed, the length of the control information field in the new A control field may be designed to be 0 bits. That is, the new A control field does not contain a control information field. This is not limited thereto.

[0247] If the new A control field indicates to the second device that it has stopped using the first time resource, then the first instruction information may be the control ID field within the A control field (i.e., if the control information field within the new A control field is designed to be 0 bits, this indicates that the new A control field does not contain a control information field. Thus, the mere presence of a control ID means that it contains the first instruction information). Alternatively, the first instruction information may be the control ID field and the control information field within the A control field (i.e., if the control information field within the new A control field is designed to contain non-zero bits, this indicates that the new A control field contains a control information field. Thus, the control ID field and the control information field congruently indicate the function of the new control field). Specifically, when the first device receives a first frame from the second device, and the first device parses the first frame and, through parsing, finds that the value of the control ID field in the A control field of the first frame is a first value, the second device may decide to stop using the first time resource based on the first value. Alternatively, when the first device receives a first frame from the second device, and the first device parses the first frame and, through parsing, finds that the value of the control ID field in the A control field of the first frame is a first value, and that the control information in the A control field contains information indicating that the first frame is a return frame (i.e., a single-user end subfield), the second device may decide to stop using the first time resource based on the first value and the value of the single-user end subfield in the control information.

[0248] Optionally, in some feasible implementations, first instruction information in the A control field of an existing type of frame (e.g., a QoS data frame or a QoS null data frame) is used to indicate that a second device has stopped using the first time resource. Furthermore, a dedicated control frame may be designed to indicate that the TXOP is recovered (i.e., the second device has stopped using the first time resource). In this application, the dedicated control frame may be referred to as a single-user-end (SU END) frame, a time resource return frame, etc., but is not limited to this application. That is, the first frame in this application may alternatively be a new type of frame, which indicates to the second device that it is returning permission to use the TXOP. Specifically, the frame type field in the first frame indicates that the first frame is a control frame, and the frame subtype field in the first frame indicates that the first frame is a time resource return frame. The time resource return frame indicates that the second device has stopped using the first time resource.

[0249] For example, Figure 8 is another schematic diagram of the structure of a first frame according to one embodiment of the present invention. As shown in Figure 8, the first frame (i.e., the SU END frame in Figure 8) may include a Frame Control field, a Duration field, a receiver address (RA) field, a transmitter address (TA) field, a frame check sequence (FCS) field, and so on. The Frame Control field includes a Protocol Version field, a Frame Type field, and a Frame Subtype field. A value of 01 in the Frame Type field indicates that the frame is a control frame, and the Frame Subtype field indicates that the first frame is a time resource return frame. As shown in Figure 8, the value of the Frame Subtype field may be set to 1111, indicating that the frame is either a SU END frame or a time resource return frame. It should be understood that the specific value of the Frame Subtype field is not limited in this application. For example, the value of the frame subtype field may alternatively be 0000, 0001, 0010, or 1111. This is not limited to the present application.

[0250] For clarity, Figure 9 shows a schematic diagram of another application scenario that restores permission to use TXOP in a UL scenario according to one embodiment of the present invention. As shown in Figure 9, in the UL scenario, for the process from when the first device (e.g., AP in Figure 9) transmits an mMU-RTS frame to when the second device (e.g., STA1 in Figure 9) transmits an SU PPDU to the SU PPDU receiver (e.g., AP in Figure 9) in the first time resource (e.g., SU SP in Figure 9), please refer to the process described in Figure 2b. Details will not be described again here. Let time t1 shown in Figure 9 be when STA1 has completed transmitting the last SU PPDU to be transmitted and has completed receiving the BA frame of the SU PPDU, time t2 shown in Figure 9 be the end of the SU SP, and the duration of STA transmitting the SU END frame be Tsu_end. Therefore, if STA1 determines that t1 + SIFS + Tsu_end ≤ t2, STA1 may send a SU END frame to the AP at time t1 + SIFS. After SIFS has elapsed since receiving the SU END frame, the AP regains permission to use TXOP. The specific value of Tsu_end can generally be determined based on the modulation and coding scheme, spatial stream, bandwidth, and the corresponding duration of sending the SU END frame in PPDU format, but is not limited to this.

[0251] For clarity, Figure 10 shows a schematic diagram of another application scenario in which permission to use TXOP in a P2P scenario is restored according to one embodiment of the present invention. As shown in Figure 10, in the P2P scenario, for the process from when the first device (e.g., AP in Figure 10) transmits an mMU-RTS frame to when the second device (e.g., STA1 in Figure 10) transmits an SU PPDU to the SU PPDU receiver (e.g., STA2 in Figure 10) in the first time resource (e.g., SU SP in Figure 10), please refer to the process described in Figure 2a. Details will not be explained again here. Suppose the end time of the SU PPDU used by STA1 is t1, the end time of the SU SP is t2, and the duration of STA transmitting an SU END frame is Tsu_end. Therefore, if STA1 determines that t1+SIFS+Tu_end≦t2, STA1 may transmit an SU END frame to AP at time t1+SIFS. After receiving a SU END frame and SIFS has elapsed, the AP regains permission to use TXOP. The specific value of Tsu_end can generally be determined based on the modulation and encoding scheme, spatial stream, bandwidth, and duration of transmitting the SU END frame in PPDU format, but is not limited to this.

[0252] Optionally, in some feasible implementations, the first frame may carry a second instruction information in addition to the first instruction information. The second instruction information indicates whether the second device requires additional time resources for data transmission. If the first frame is a QoS data frame or a QoS null data frame, and the A control field in the QoS data frame or QoS null data frame is a CAS control field, then the first instruction information may be the RDG subfield in the CAS control field, and the second instruction information may be at least one bit in bits 4 through 8 of the CAS control field. If the first frame is a QoS data frame or a QoS null data frame, and the A control field in the QoS data frame or QoS null data frame is a new A control field, then the first instruction information may be the control identifier of the new A control field, and the second instruction information may be at least one bit in bits 2 through 8 of the control information field in the new A control field. If the first frame is a SU END frame (i.e., the first frame is a control frame for ), the first instruction information may be a frame subtype field in the frame control field, and the second instruction information may be at least one reserved field selected from the reserved fields in the frame control field, etc. This is not limited to the above.

[0253] For clarity, the first and second instruction information will be described below using an example in which the first frame is a QoS data frame and the A control field within the QoS data frame is a CAS control field. Figure 11(a) is another schematic diagram of the structure of the first frame according to one embodiment of the present application. As shown in Figure 11(a), when the control identifier = 6, it indicates that the A control field is a CAS control field. Specifically, in the control information field within the CAS control field, the first bit indicates the Access Type Constraint (AC Constraint) subfield, the second bit indicates the Reverse Approval / More PPDU (RDG / More PPDU) subfield, the third bit indicates the Parameter-Based Spatial Reuse Transmission (PSRT PPDU) subfield, and the fourth through eighth bits indicate the Reserved field. Thus, in this embodiment of the present application, at least one bit in the fourth through eighth bits indicates whether the second device requires further time resources to be used for data transmission. In other words, in this application, at least one bit of the reserved field may be used as a request field for requesting time resources again. For example, one bit of the reserved field (e.g., the fourth bit in Figure 11(a)) may be used as the request field. If the request field is set to 1, it may indicate that the second device needs further SU SP, and therefore requests the AP to continue allocating time resources to the second device thereafter. If the request field is set to 0, it indicates that the second device no longer needs SU SP. Optionally, it may be further specified that if the request field is set to 0, it indicates that the second device needs further SU SP, and therefore requests the AP to continue allocating said time resources to the second device thereafter. If the request field is set to 1, it indicates that the second device no longer needs SU SP. This will be specifically determined on the actual application scenario, and is not limited herein.Furthermore, when the aforementioned 1-bit reserved field is used as the request field, it should be understood that the request field may alternatively be any single bit between the 4th and 8th bits in the CAS control field. This will be determined specifically based on the actual application scenario and is not limited thereto.

[0254] As another example, Figure 11(b) is another schematic diagram of the structure of a first frame according to one embodiment of the present application. As shown in Figure 11(b), when the A control field is a CAS control field, in the control information field within the CAS control field, the first bit indicates the Access Type Constraint (AC Constraint) subfield, the second bit indicates the Reverse Approval / More PPDU (RDG / More PPDU) subfield, the third bit indicates the Parameter-Based Spatial Reuse Transmission (PSRT PPDU) subfield, and the fourth through eighth bits indicate the Reserved field. If two reserved bits (for example, the fourth and fifth bits in Figure 11(b)) are used as the request field, then if the value of the request field is 00 (i.e., the value of the fourth bit is 0 and the value of the fifth bit is 0), it may indicate that the STA does not require an SU SP (i.e., the STA does not require an SU SP for UL transmission and does not require an SU SP for P2P transmission). If the value of the request field is 01 (i.e., the value of the 4th bit is 0 and the value of the 5th bit is 1), the request field may indicate that the STA requires an SU SP for UL transmission (i.e., the STA requires an SU SP for UL transmission but not for P2P transmission). If the value of the request field is 10 (i.e., the value of the 4th bit is 1 and the value of the 5th bit is 0), the request field may indicate that the STA requires an SU SP for P2P transmission (i.e., the STA requires an SU SP for P2P transmission but not for UL transmission). If the value of the request field is 11 (i.e., the value of the 4th bit is 1 and the value of the 5th bit is 1), the request field may indicate that the STA requires an SU SP for both UL and P2P transmission (i.e., the STA requires an SU SP for both UL and P2P transmission). It should be understood that the specific meaning indicated by the different values ​​may be determined based on the actual application scenario. This is not limited to this.

[0255] Optionally, if a 2-bit reserved field is used as the request field, the request field may alternatively be any two consecutive bits in bits 4 through 8 of the CAS control field (for example, bits 4 and 5, bits 5 and 6, bits 6 and 7, or bits 7 and 8). Optionally, if a 2-bit reserved field is used as the request field, the request field may alternatively be any two non-consecutive bits in bits 4 through 8 of the CAS control field. Any two non-consecutive bits may be two bits separated by one bit, for example, bits 4 and 6, or bits 5 and 7, or bits 6 and 8. Optionally, any two non-consecutive bits may alternatively be two bits separated by two bits, for example, bits 4 and 7, or bits 5 and 8. Optionally, any two non-consecutive bits may be two bits separated by three bits, for example, the fourth and eighth bits. This is not limited to the present.

[0256] Optionally, in some feasible implementations, regardless of whether it is a P2P or UL scenario, the 802.11 protocol specifies that a second device may transmit a SU PPDU carrying service data only within the duration of a first time resource. Transmitting a SU PPDU carrying service data only within the duration of a first time resource means: completing the transmission of the SU PPDU before the end of the first time resource and transmitting a BA frame that requires a response. Thus, for a UL scenario, if the first frame is a QoS data frame (a QoS data frame is a QoS data frame carrying an enhanced CAS control field, or a QoS data frame carrying a new A control field), the QoS data frame still needs to be completed before the end of the first time resource. If the first frame is a frame that does not carry service data (i.e., the first frame is not a QoS data frame), it may be stipulated that the first frame may be allowed to extend beyond the end of the first time resource, i.e., cross-boundary transmission is permitted. For example, in a P2P or UL scenario, if the first frame is a SU END frame, the transmission of the SU END frame may be permitted to extend beyond the end of the first time resource. That is, the end of the SU END frame may be later than the end of the first time resource, and the start of the SU END frame may be earlier than the end of the first time resource. As another example, in a P2P scenario, if the first frame is a QoS null data frame, the transmission of the QoS null data frame may also be permitted to extend beyond the end of the first time resource. That is, the end of the QoS null data frame may be later than the end of the first time resource, and the start of the QoS null data frame may be earlier than the end of the first time resource.

[0257] For clarity, Figure 13 shows a schematic diagram of a UL scenario in which cross-boundary transmission of SU END frames is permitted in one embodiment of the present invention. As shown in Figure 13, for the process in the UL scenario from when the first device (e.g., AP in Figure 13) transmits an mMU-RTS frame to when the second device (e.g., STA1 in Figure 13) transmits a SU PPDU in the first time resource (e.g., SU SP in Figure 13) to the SU PPDU receiver (e.g., AP in Figure 13), please refer to the process described in Figure 2b. Details will not be explained again here. After STA1 has completed the transmission of the last SU PPDU in the first time resource and has successfully received the BA frame transmitted by AP, if the SIFS has elapsed after STA1 has received the BA frame and the end of the first time resource has not been exceeded, STA1 immediately transmits one SU END frame to AP, indicating to AP that STA1 has stopped using the first time resource. The first device (for example, the AP in Figure 13) immediately regains permission to use TXOP after SIFS has elapsed following the receipt of the SU END frame.

[0258] Optionally, Figure 14 is a schematic diagram of a P2P scenario according to one embodiment of the present invention in which cross-boundary transmission of SU END frames is permitted. As shown in Figure 14, for the process in the P2P scenario from when the first device (e.g., AP in Figure 14) transmits an mMU-RTS frame to when the second device (e.g., STA1 in Figure 14) transmits a SU PPDU on the first resource (e.g., SU SP in Figure 14) to the SU PPDU receiver (e.g., STA2 in Figure 14), please refer to the process described in Figure 2a. Further details will not be described again here. After STA1 has completed the transmission of the last SU PPDU on the first time resource and has successfully received the BA frame transmitted by STA2, if the end of the first time resource has not been reached when SIFS has elapsed after STA1 has received the BA frame, STA1 immediately transmits one SU END frame to AP, indicating to AP that STA1 has stopped using the first time resource. After receiving a SU END frame and SIFS has elapsed, the AP immediately regains permission to use TXOP.

[0259] Optionally, Figure 15 shows a schematic diagram of another application scenario in which permission to use TXOP in a P2P scenario is restored according to one embodiment of the present invention. As shown in Figure 15, in the P2P scenario, for the process from when the first device (e.g., AP in Figure 15) transmits an mMU-RTS frame to when the second device (e.g., STA1 in Figure 15) transmits an SU PPDU in the first time resource (e.g., SU SP in Figure 15) to the SU PPDU receiver (e.g., STA2 in Figure 15), please refer to the process described in Figure 2a. Further details will not be described again here. After STA1 has completed transmitting the last SU PPDU in SU SP and successfully received the BA frame transmitted by STA2, if the SIFS has elapsed after STA1 has received the BA frame and the SU SP has not ended, STA1 immediately sends one QoS null data frame to AP to indicate to AP that the SU SP is no longer in use. After receiving a QoS null data frame, the AP immediately regains permission to use TXOP once SIFS has elapsed.

[0260] In this embodiment of the present application, the first frame may be a frame carrying a frame control field, and the second device indicates whether to stop using the first time resource by using an additional data subfield in the frame control. If the additional data subfield is set to 1, it indicates to stop using the first time resource, and if the additional data subfield is set to 0, it indicates not to stop using the first time resource. In another example, if the additional data subfield is set to 0, it indicates to stop using the first time resource, and if the additional data subfield is set to 1, it indicates not to stop using the first time resource.

[0261] The structure of the frame control field is shown in Figure 12. The frame transmitted by the AP to a station supporting power saving now has the additional data subfield, which indicates whether the AP buffers additional data for the target STA. If the additional data subfield is set to 1, it indicates that the additional buffered data exists. If the additional data subfield is set to 0, it indicates that no further buffered data exists. Similarly, a TDLS station may use the additional data subfield to indicate whether the TDLS station has additional buffered data for a TDLS receiving station in power saving mode. In the prior art, the additional data subfield is not used in scenarios where a non-AP STA transmits to an associated AP, and the additional data subfield is set to 0.

[0262] Specifically, in one possible implementation, the first device is an AP, and the second device can be one of two things: one is a non-AP STA associated with the first device, and the other is an Overlapping Basic Service Set (OBSS) AP.

[0263] If the second device is a non-AP STA associated with the first device, the technical solution in this embodiment of the Application uses the additional data subfield in a frame transmitted by the non-AP STA to the associated AP to indicate whether to stop using the first time resource. In this case, if the additional data subfield is set to 0, it indicates that the non-AP STA will not stop using the first time resource, rather than indicating that the non-AP STA will not use the additional data subfield. If the non-AP STA transmits to a station different from the associated AP, the value of the additional data subfield does not indicate whether to stop using the first time resource. In this scenario, the specific meaning of the value of the additional data subfield may conform to, or be redefined, a function in an existing protocol that indicates whether there is buffered data. This is not limited herein. The station different from the associated AP may be a non-AP STA or the AP. This is not limited herein.

[0264] If the second device is an OBSS AP, the technical solution in this embodiment of the Application uses the additional data subfield in the frame transmitted by the OBSS AP to the first device to indicate whether to stop using the first time resource. For example, if the additional data subfield is set to 0, it indicates that to stop using the first time resource. If the OBSS AP transmits to a station different from the first device, the value of the additional data subfield does not indicate whether to stop using the first time resource. In this scenario, the specific meaning of the value of the additional data subfield may conform to or be redefined a function in an existing protocol that indicates whether there is buffered data. This is not limited to the Application. The station different from the first device may be a non-AP STA or an AP. This is not limited to the Application.

[0265] Furthermore, an additional data subfield may indicate whether to stop using the first time resource, and since such a function is different from the original function of the additional data subfield, the additional data subfield may have a different name, for example, More Data / TXOP Sharing Termination. It should be noted that whether or not the name is modified does not affect the use of the function of the additional data subfield.

[0266] This technical solution indicates whether existing additional data subfields should stop using the first time resource, thereby maximizing the use of existing fields within the additional data subfields and preventing the addition of new fields. This can reduce instructional overhead and aid in product implementation.

[0267] S102: The first device regains permission to use TXOP based on the first frame.

[0268] In some possible implementations, when the first device receives the first frame from the second device, the first device can obtain the first instruction information carried in the first frame by parsing the first frame, and further restore the permission to use the TXOP based on the first instruction information. Optionally, when the first device receives the first frame from the second device, if the first device obtains the first instruction information and the second instruction information carried in the first frame by parsing the first frame, the first device may restore the permission to use the TXOP based on the first instruction information, and continue to allocate new time resources to the second device from the remaining duration of the TXOP based on the second instruction information.

[0269] In this embodiment of the present application, the first frame indicates that the second device has stopped using the allocated time resource (the first time resource). Therefore, the first device withdraws or restores the permission to use the TXOP in advance based on the instruction of the first frame. This can improve the utilization rate of channel resources and the reliability of restoring the permission to use the TXOP.

[0270] Furthermore, an embodiment of the present application further provides a method for restoring the permission to use the transmission opportunity. In this embodiment of the present application, mainly in the standard protocol, when the transmission and reception of any frame are not allowed to exceed the end point of the first time resource, the first device can restore or withdraw the permission to use the TXOP by setting a preset duration T (that is, the time threshold T).

[0271] Specifically, FIG. 16 is another schematic flowchart of a method for restoring the permission to use the transmission opportunity according to an embodiment of the present application. As shown in FIG. 16, the method for restoring the permission to use the transmission opportunity includes the following steps.

[0272] S201: The first device receives the second frame.

[0273] In some feasible implementations, when the first device receives the second frame at any point in the first time resource, it may further decide whether to pre-recover permission to use TXOP based on a value relationship between a pre-configured duration T and the duration between the end of the second frame and the end of the first time resource. In other words, the first device needs to determine in real time whether the received second frame satisfies the conditions for recovering permission to use TXOP. The second frame may be a frame whose destination address (also called the receiver address) is the address of the second device, or it may be a frame whose sender address is the address of the second device and does not request an acknowledgment frame.

[0274] For example, in a P2P scenario, a second frame received by the first device, whose destination address is the address of the second device, may be a BA frame sent to the second device by an SU PPDU receiver (i.e., another station STA). As shown in Figure 17, STA1 sends an SU PPDU to STA2, and STA2 responds to STA1 with a BA frame. That is, the destination address of the BA frame is STA1 (which in this embodiment of the application is understood to be the second device), and the BA frame may also in this embodiment of the application be understood to be the second frame. In a WLAN system, since the mode of communication between devices is broadcast, the first device (e.g., the AP in Figure 17) may receive a BA frame sent to the second device by an SU PPDU receiver (e.g., STA2 in Figure 17). Optionally, in a P2P scenario, a second frame received by the first device, whose sender address is the address of the second device, may be an SU PPDU sent by the second device to an SU PPDU receiver, which does not request a BA frame. Alternatively, the second frame may be a management frame sent by a second device, etc. This will be specifically determined based on the actual application scenario and is not limited thereto.

[0275] For example, in a UL scenario, the first device receives a second frame whose sender address is the address of the second device, and the second frame does not request a response frame. For example, the second frame may be a SU PPDU sent by the second device to the first device that does not request a BA frame. Alternatively, the second frame may be a management frame sent by the second device, etc. This is not limited to these examples. Optionally, in a UL scenario, since the first device is the recipient of the SU PPDU, the first device may further decide whether to revoke permission to use TXOP by using the duration between the end of the BA frame sending the SU PPDU and the end of the first time resource.

[0276] S202: The first device regains permission to use TXOP if the duration between the end of the second frame and the end of the first time resource is shorter than a pre-configured duration T.

[0277] In some feasible implementations, if the first device receives a second frame and determines that the duration between the end of the second frame and the end of the first time resource is shorter than a pre-configured duration T, the first device regains permission to use TXOP. Conversely, if the first device determines that the duration between the end of the second frame and the end of the first time resource is longer than a pre-configured duration T, the first device does not regain permission to use TXOP.

[0278] Specifically, in a P2P scenario, when the first device receives an acknowledgment frame at any point in the first time resource, and the first device determines that the destination address of the acknowledgment frame is the address of the designated STA in the first time resource (i.e., the address of the second device), the first device may determine whether the duration between the end of the acknowledgment frame and the end of the first time resource is less than T. If the duration is less than T, the first device regains permission to use TXOP immediately after SIFS. Conversely, if the duration is greater than T, the first device does not regain permission to use TXOP. Alternatively, when the first device receives a frame at any point in the first time resource that does not request a response frame, and the sender address of the frame that does not request a response frame is the address of the designated STA in the first time resource (i.e., the address of the second device), the first device may determine whether the duration between the end of the frame and the end of the first time resource is less than T. If the duration is less than T, the first device can immediately regain permission to use TXOP after SIFS. Conversely, if the duration is longer than T, the first device will not regain permission to use TXOP.

[0279] Specifically, in the UL scenario, when the first device receives a frame that does not request a response frame at any point in the first time resource, and the sender address of the frame that does not request a response frame is the address of the designated STA in the first time resource (i.e., the address of the second device), the first device determines whether the duration between the end of the frame and the end of the first time resource is less than T. If the duration is less than T, the first device can immediately regain permission to use TXOP after SIFS. Conversely, if the duration is greater than T, the first device does not regain permission to use TXOP.

[0280] For clarity, Figure 17 shows a schematic diagram of the scenario according to the present invention in which permission to use TXOP is restored based on a pre-configured duration T in a P2P scenario. As shown in Figure 17, in the P2P scenario, for the process from when the first device (e.g., AP in Figure 17) transmits an mMU-RTS frame to when the second device (e.g., STA1 in Figure 17) transmits an SU PPDU to an SU PPDU receiver (e.g., STA2 in Figure 17) in the first time resource (e.g., SU SP in Figure 17), please refer to the process described in Figure 2a. Further details will not be explained again here. If AP receives a BA frame at any point in the first time resource and the destination address of the BA frame is the address of STA1, AP can immediately restore permission to use TXOP after SIFS if it determines that the duration between the end of the BA frame and the end of the SU SP (e.g., T' in Figure 17) is shorter than the pre-configured duration T. Conversely, if T' is greater than T, the AP does not regain permission to use TXOP. Correspondingly, if STA1 receives a BA frame at any point in the first time resource and determines that the duration T' between the end of the BA frame and the end of the SU SP is less than T, STA1 defaults to restoring permission for the AP to use TXOP; that is, STA considers it no longer permitted to send SU PPDUs for the remainder of the SU SP duration. Conversely, if STA1 determines that the duration T' is greater than T, STA can continue to use SU SP.

[0281] Optionally, in some feasible implementations, after the first device determines that the duration between the end of the second frame and the end of the first time resource is equal to a pre-configured duration T, the first device may choose to reclaim permission to use TXOP. Alternatively, the first device may choose not to reclaim permission to use TXOP. This will be determined specifically based on the actual application scenario, and is not limited herein.

[0282] Correspondingly, if the duration from the end of receiving the second frame on the second device to the end of the first time resource is shorter than the pre-configured duration T, or if the duration from the end of transmitting the second frame on the second device to the end of the first time resource is shorter than the pre-configured duration T, the second device will no longer transmit a PPDU. Conversely, if the duration from the end of receiving the second frame on the second device to the end of the first time resource is longer than the pre-configured duration T, or if the duration from the end of transmitting the second frame on the second device to the end of the first time resource is longer than the pre-configured duration T, the second device may continue to use the first time resource.

[0283] Specifically, in a UL or P2P scenario, when a second device receives an acknowledgment frame at any point in the first time resource, the second device can determine if the duration between the end of the acknowledgment frame and the end of the first time resource is less than T. If the duration is less than T, the second device defaults to restoring permission for the first device to use TXOP, meaning the second device is no longer permitted to send SU PPDUs for the remainder of the first time resource. Conversely, if the duration is longer than T, the STA may continue to use SU SPs. Alternatively, when a second device sends a frame at any point in the first time resource that does not request a response frame, the second device determines if the duration between the end of the response frame and the end of the first time resource is less than T. If the duration is less than T, the second device defaults to restoring permission for the first device to use TXOP, meaning the second device will no longer send SU PPDUs for the remainder of the first time resource. Conversely, if the duration is greater than T, the second device may continue to use the first time resource.

[0284] It can be understood that if the duration between the end of the second device receiving the second frame and the end of the first time resource is equal to a pre-configured duration T, or if the duration between the end of the second device transmitting the second frame and the end of the first time resource is equal to a pre-configured duration T, then whether the second device chooses to continue using the first time resource should be consistent with whether the first device chooses to reclaim its TXOP usage authorization. For example, if the first device is specified to choose to reclaim its TXOP usage authorization when it determines that the duration between the end of the second frame and the end of the first time resource is equal to a pre-configured duration T, then the second device must choose not to transmit a PPDU frame if the duration between the end of the second frame and the end of the first time resource is equal to a pre-configured duration T. Correspondingly, if the first device is specified to choose not to reclaim permission to use TXOP when it determines that the duration between the end of the second frame and the end of the first time resource is equal to a pre-configured duration T, the second device may be specified to choose to continue using the first time resource if the duration between the end of the second frame and the end of the first time resource is equal to a pre-configured duration T.

[0285] Optionally, in some feasible implementations, if the second frame is the last SU PPDU sent by the second device when the second device uses the first time resource, or if the second frame is the BA frame of the last SU PPDU sent by the second device when the second device uses the first time resource, the second device may, to prevent wasting channel resources, send a first frame to the first device to indicate that the second device has stopped using the first time resource. Correspondingly, the first device receives the first frame from the second device, parses information about the first frame, and thereby can regain permission to use TXOP based on the first frame. For a solution in this embodiment of the present application in which the second device sends a first frame to indicate that the second device has stopped using the first time resource, see the process described in Embodiment 1. I won't go into further detail here.

[0286] In this embodiment of the present application, in P2P and UL scenarios, the first device can determine whether to restore or revoke permission for the first device to use TXOP by determining the value relationship between a time threshold (i.e., a pre-configured duration T in the present application) and the duration T' between the end time at which a second frame is received at any given time and the end time of the first time resource. According to the solution in this embodiment of the present application, permission to use TXOP is restored if T' is less than T, and permission to use TXOP may also be restored in advance. This can improve the utilization of channel resources and the reliability of restoring permission to use TXOP.

[0287] Furthermore, in a UL scenario, the first device may alternatively transmit a second frame and determine whether to restore or revoke the permission to use the first device's TXOP based on a time threshold (i.e., a pre-configured duration T in this application) and a value relationship between the end of the second frame and the duration T' between the end of the first time resource.

[0288] Specifically, Figure 18 is another schematic flowchart of a method for restoring permission to use a transmission opportunity according to one embodiment of the present invention. As shown in Figure 18, the method for restoring permission to use a transmission opportunity includes the following steps:

[0289] S301: The first device sends the second frame.

[0290] In some feasible implementations, in a UL scenario, the first device may alternatively send a second frame to the second device and decide whether to restore permission to use TXOP based on a pre-configured duration T and a value relationship between the duration between the end of the second frame and the end of the first time resource. Generally, the second frame sent by the first device in a UL scenario is a BA frame returned by the first device to the second device based on the SU PPDU received from the second device. Furthermore, in a UL scenario, the second device receives the BA frame sent by the first device and decides whether to continue using the first time resource based on a pre-configured duration T and a value relationship between the duration between the end of the second frame and the end of the first time resource.

[0291] S302: The first device restores permission to use the transmit opportunity TXOP if the duration between the end of the second frame and the end of the first time resource is shorter than the pre-configured duration T.

[0292] In some possible implementations, when the duration between the end of the second frame and the end of the first time resource is shorter than a preset duration T, the first device resumes the permission to use the transmission opportunity TXOP. The first time resource is allocated by the first device from the obtained TXOP to the second device. Conversely, if the second device determines that the duration between the end of the second frame and the end of the first time resource is shorter than the preset duration T, by default, the second device considers that the first device resumes the use of the TXOP. That is, the second device is no longer allowed to transmit the SU PPDU even in the remaining duration of the SU SP.

[0293] Optionally, in some possible implementations, when the second device determines that the duration between the end of the second frame and the end of the first time resource is greater than T, to prevent waste, the second device can send the first frame to the first device and indicate that the second device has stopped using the first time resource. Correspondingly, the first device receives the first frame from the second device, parses the first frame, and thereby the first device can resume the permission to use the TXOP based on the first frame. For the solution in this embodiment of the present application where the second device sends the first frame to indicate that the second device has stopped using the first time resource, refer to the process described in Embodiment 1. Details are not described here.

[0294] For clarity, Figure 19 shows a schematic diagram of a scenario in which permission to use TXOP is restored based on a pre-configured duration T in a UL scenario according to the present invention. As shown in Figure 19, for the process in a UL scenario from the time when the first device (e.g., AP in Figure 19) transmits an mMU-RTS frame to the time when the second device (e.g., STA1 in Figure 19) transmits an SU PPDU to the SU PPDU receiver (e.g., AP in Figure 19) in the first resource (e.g., SU SP in Figure 19), please refer to the process described in Figure 2a. Details will not be explained again here. When AP transmits a BA frame to STA1 at any point in the first time resource, if AP determines that the duration between the end of the BA frame and the end of the SU SP (e.g., T' in Figure 19) is shorter than the pre-configured duration T, AP can immediately restore permission to use TXOP after SIFS. Conversely, if T' is greater than T, AP does not restore permission to use TXOP. Correspondingly, if STA1 receives a BA frame at any point in the first time resource and determines that the duration T' between the end of the BA frame and the end of the SU SP is less than T, STA1 defaults to considering the AP to have regained permission to use TXOP. In other words, STA1 is no longer permitted to send SU PPDUs for the remainder of the SU SP duration. Conversely, if STA1 determines that the duration T' is greater than T, STA1 may continue to use SU SPs.

[0295] In this embodiment of the present application, in a UL scenario, the first device transmits a second frame, and a decision can be made whether to restore / revoke the permission to use the TXOP for the first device based on a time threshold (i.e., a pre-configured duration T in the present application) and a value relationship between the end of the second frame and the duration T' between the end of the first time resource. According to the solution in this embodiment of the present application, if T' is less than T, the permission to use the TXOP is restored, and the permission to use the TXOP may also be restored in advance. This can improve the utilization of channel resources and the reliability of restoring permission to use the TXOP.

[0296] Furthermore, in another embodiment of the present application, if an AP needs to revoke its authorization to use TXOP for a reason (e.g., an urgent service that should be sent immediately is arriving), the AP can actively reclaim / revoke its authorization to use TXOP by sending an active reclaim frame (i.e., the third frame in the present application). For the purposes of this description, an example in which this embodiment applies to a UL scenario is used below. It can be understood that this embodiment may also apply to other scenarios, and is not limited to the present application.

[0297] Specifically, Figure 20 is another schematic flowchart of a method for restoring permission to use a transmission opportunity according to one embodiment of the present invention. As shown in Figure 20, the method for restoring permission to use a transmission opportunity includes the following steps:

[0298] S401: The first device determines the third frame.

[0299] In some feasible implementations, if an AP needs to revoke its authorization to use TXOP for some reason (for example, if an urgent service that should be sent immediately is arriving), the AP can send a third frame to indicate to a second device that the first device is immediately revoking or plans to revoke its authorization to use TXOP. Therefore, after receiving the third frame, the second device will no longer send SU PPDUs for the remaining duration of the first device's time resource.

[0300] The third frame may be an improved BA frame. That is, the frame structure of the BA frame that is fed back to the second device by the first device may be modified. The improved BA frame may indicate that the BA frame is a response frame from the first device based on the SU PPDU received from the second device, and may also indicate that the first device is actively recovering permission to use TXOP. The BA Control field may be modified, so that the BA Control field may indicate that the first device is actively recovering permission to use TXOP. Specifically, at least one bit in the reserved field of the BA Control field may be set as a TXOP Recovery Indication field. For example, if the 1 bit contained in the reserved field in the BA control field is set as the TXOP recovery instruction field, then it may be defined that when the TXOP recovery instruction field is set to 1, it indicates that the first device will immediately recover permission to use the TXOP; and when the field is set to 0, it indicates that the first device will not recover permission to use the TXOP. Alternatively, when the TXOP recovery instruction field is set to 0, it indicates that the first device will immediately recover permission to use the TXOP; and when the field is set to 1, it indicates that the first device will not recover permission to use the TXOP. This is not limited to the above.

[0301] For clarity, Figure 21 shows a schematic diagram of the structure of an improved BA frame according to one embodiment of the present invention. As shown in Figure 21, a BA frame may include a Frame Control field, a Duration field, a Receiver Address (RA) field, a Sender Address (TA) field, a BA Control field, a BA Information field, a Frame Check Sequence (FCS) field, and so on. Existing standard protocols (i.e., 802.11ax) specify that the BA Control field may contain 16 bits. The first bit indicates the Block Ack Policy field, the second through fifth bits indicate the Block Type field, the sixth through twelfth bits indicate the Reserved field, and the thirteenth through sixteenth bits indicate the Service Identifier Information (TID_INFO) field. To improve the BA Control field, at least one bit in the sixth through twelfth bits of the BA Control field may indicate a TXOP recovery instruction field. For example, if the 1 bit included in the reserved field in the BA control field indicates the TXOP recovery instruction field, then any 1 bit from the 6th to the 12th bit can be set as the TXOP recovery instruction field. For example, the 6th bit in the BA control field in Figure 21 is set as the TXOP recovery instruction field.

[0302] Furthermore, Figure 22 shows a schematic diagram of an application scenario in which the first device actively recovers permission to use TXOP according to the present invention. As shown in Figure 22, in the UL scenario, for the process from the time the first device (e.g., AP in Figure 22) transmits an mMU-RTS frame to the time the second device (e.g., STA1 in Figure 22) transmits an SU PPDU to the SU PPDU receiver (e.g., AP in Figure 22) on the first time resource (e.g., SU SP in Figure 22), please refer to the process described in Figure 2a. Details will not be described again here. If the AP needs to actively recover / revoke permission to use TXOP, the AP can use any BA frame to indicate to STA1 that the AP is intending to revoke permission to use TXOP. As shown in Figure 22, the AP sends one improved BA frame (i.e., the third frame in this application) to STA1, and when the SIFS has elapsed after the improved BA frame has been sent, it regains permission to use TXOP (for example, the AP sends the PPDU in Figure 22).

[0303] Optionally, the frame structure of the BA frame does not need to be modified / improved, and another frame (i.e., a fourth frame in this application) is aggregated with the BA frame. This other frame indicates that the first device is actively recovering permission to use TXOP. In other words, the third frame is an aggregate frame, which is obtained by aggregating the BA frame with another frame (i.e., a fourth frame). It should be understood that in this application, it is permissible for any fourth frame having such a function to be aggregated. For example, the A control field in the fourth frame contains third instruction information. The third instruction information indicates that the first device is actively recovering permission to use transmit opportunity TXOP. Specifically, the fourth frame may be a QoS data frame or a QoS null data frame, and the A control field of the fourth frame carries a new type of A control field (e.g., the value of the control identifier is 7). See Figure 7 for the frame structure of the fourth frame. Further details will not be described again here. Optionally, the frame type field in the third frame indicates that the third frame is a control frame, and the frame subtype field in the third frame indicates that the third frame is an active recovery frame. An active recovery frame indicates that the first device actively recovers permission to use the transmit opportunity TXOP. In other words, another new control frame (for example, with a frame type field of binary 01 and a frame subtype field of binary 1111) may be further designed to indicate that the first device actively recovers permission to use the transmit opportunity TXOP. For simplicity of explanation, the new control frame is sometimes called an active recovery frame. See Figure 8 for the frame structure of the active recovery frame. Further details will not be explained again here.

[0304] For clarity, Figure 23 shows another schematic diagram of an application scenario in which the first device actively recovers permission to use TXOP. As shown in Figure 23, in the UL scenario, for the process from when the first device (e.g., AP in Figure 23) transmits an mMU-RTS frame to when the second device (e.g., STA1 in Figure 23) transmits an SU PPDU to the SU PPDU receiver (e.g., AP in Figure 23) on the first time resource (e.g., SU SP in Figure 23), please refer to the process described in Figure 2a. Further details will not be described again here. If the AP needs to actively recover / revoke permission to use TXOP, the AP may aggregate any BA frame with another frame (i.e., a fourth frame in this application). The aggregated frame indicates to STA1 that the AP is recovering permission to use TXOP. As shown in Figure 23, after aggregating the BA frame and another frame into a third frame, the AP sends the third frame to STA1, indicating to STA1 that the AP is restoring permission to use TXOP. The AP may revoke permission to use TXOP after SIFS has elapsed following the transmission of the third frame (for example, the AP sends the PPDU in Figure 23).

[0305] S402: The first device sends the third frame to the second device.

[0306] In some feasible implementations, after determining the third frame, the first device may send the third frame to the second device. It may be understood that, after sending the third frame, the first device may revoke permission to use TXOP when SIFS has elapsed. Alternatively, after sending the third frame, the first device may wait for the second device to retransmit the data frame k times, and then revoke permission to use TXOP. In other words, after sending the third frame, the first device may revoke permission to use TXOP when a predetermined duration T0 has elapsed. This is a buffer time provided by the first device to the second device, or sufficient time is reserved for other preparations. To simplify the explanation, the statement "The first device may revoke permission to use TXOP after SIFS has elapsed following the transmission of the third frame" may be briefly written as "The first device immediately revokes permission to use TXOP," and the statement "After transmitting the third frame, the first device may wait for the second device to retransmit the data frame k times, and then revoke permission to use TXOP" may be briefly written as "The first device delays revoking permission to use TXOP," where k is an integer greater than 0 (for example, k=1).

[0307] It may be understood that when the second device receives the third frame from the first device, the second device no longer transmits data frames (i.e., if the first device immediately revokes its TXOP authorization, the second device is not permitted to retransmit data frames at all). Alternatively, the second device may be permitted to retransmit data frames k times (i.e., the first device may delay revoking its TXOP authorization, and the second device may be permitted to retransmit data frames k more times). The third frame may be an improved BA frame or an aggregated frame.

[0308] For clarity, please refer to Figure 22 or Figure 23. If the AP needs to immediately and actively revoke its authorization to use TXOP, the AP may use an arbitrary BA frame to indicate to STA1 that the AP is immediately revoking its authorization to use TXOP. That is, the AP sends one improved BA frame to STA1, and when SIFS has elapsed after the BA frame has been sent, it revoks its authorization to use TXOP (for example, the AP sends a PPDU in Figure 22).

[0309] For clarity, Figure 24 shows another schematic diagram of an application scenario in which the first device actively reclaims permission to use TXOP according to the present invention. As shown in Figure 24, in the UL scenario, for the process from when the first device (e.g., AP in Figure 24) transmits an mMU-RTS frame to when the second device (e.g., STA1 in Figure 24) transmits an SU PPDU to the SU PPDU receiver (e.g., AP in Figure 24) on the first time resource (e.g., SU SP in Figure 24), please refer to the process described in Figure 2a. Further details will not be described again here. If AP needs to actively revoke permission to use TXOP, AP may transmit an improved BA frame to STA1 to indicate that AP is revoking permission to use TXOP. In the scenario shown in Figure 24, AP may allow STA1 to retransmit the SU PPDU once after STA1 has received the improved BA frame (i.e., k=1). Therefore, after the AP sends an improved BA frame to STA1, the AP may formally revoke / recover permission to use TXOP after a duration T0 has elapsed, once it has finished sending the BA frame (for example, the AP sends a PPDU as shown in Figure 24). T0 = 3SIFS + SU PPDU + BA.

[0310] In this embodiment of the present application, if an AP needs to revoke its authorization to use TXOP for a reason (e.g., an urgent service that should be transmitted immediately is arriving), the AP can actively reinstate / revoke its authorization to use TXOP by transmitting an active reinstatement frame (i.e., the third frame in the present application). Such an active revocation mode allows the AP to reinstate its authorization to use TXOP as needed.

[0311] The relevant features of the aforementioned method embodiments may be combined. This is not limited to the present invention.

[0312] The above description details the method provided in this application. To implement the aforementioned solution in the embodiments of this application, embodiments of this application further provide a corresponding apparatus or device.

[0313] In embodiments of the present application, the first and second devices may be divided into functional modules based on the method examples described above. For example, functional modules may be obtained through division based on corresponding functions, or two or more functions may be integrated into a single processing module. The integrated module may be implemented in hardware form or in the form of a software functional module. In this embodiment of the present application, the module division is illustrative and merely a logical functional division. In actual implementations, other division patterns may be used. Below, a device for restoring permission to use a transmission opportunity according to one embodiment of the present application will be described in detail with reference to Figures 25 and 26.

[0314] When an integrated unit is used, Figure 25 is a schematic diagram of the structure of a device 1 for restoring permission to use a transmission opportunity according to one embodiment of the present invention. The device for restoring permission to use a transmission opportunity may be a first device or a chip within the first device, such as a Wi-Fi chip. As shown in Figure 25, the device for restoring permission to use a transmission opportunity includes a processing unit 11 and a transceiver unit 12.

[0315] In one design, the transceiver unit 12 is configured to receive a first frame from a second device. The first frame indicates that the second device has stopped using the first time resource. The first time resource is allocated to the second device by the first device from an acquired transmit opportunity TXOP. The first time resource is allocated to the second device by the first device using a single-user trigger frame. The processing unit 11 is configured to restore permission to use the TXOP based on the first frame.

[0316] Optionally, the first time resource is used for the transmission of Single User Physical Layer Protocol Data Units (PPDUs) on the uplink or for point-to-point P2P communication. A single-user trigger frame includes a first field and a second field. The first field indicates the remaining time resource of the TXOP, and the second field indicates the first time resource.

[0317] Optionally, the first frame carries first instruction information. The first instruction information indicates that the second device has stopped using the first time resource.

[0318] Optionally, the first frame may also carry second instruction information, which indicates whether the second device requires additional time resources for data transmission.

[0319] Optionally, the A control field in the first frame includes first instruction information. Alternatively, the A control field in the first frame includes both first and second instruction information.

[0320] Optionally, the control identifier of the A control field is a first value. The first value indicates that the A control field contains first instruction information.

[0321] Optionally, the control identifier of the A control field is a second value. The second value indicates that the A control field is a command and status CAS control field. The first instruction information is carried in the reverse approval RDG subfield within the CAS control field. Alternatively, the first instruction information is carried in the RDG subfield within the CAS control field, and the second instruction information is carried in at least one bit between bits 4 and 8 within the CAS control field.

[0322] Optionally, the frame type field within the first frame indicates that the first frame is a control frame, and the frame subtype field within the first frame indicates that the first frame is a time resource return frame. A time resource return frame indicates that the second device has stopped using the first time resource.

[0323] In an alternative design, the transceiver unit 12 is configured to receive a second frame. The processing unit 12 is configured to: restore permission to use the transmit opportunity TXOP if the duration between the end of the second frame and the end of the first time resource is shorter than a preset duration T. The destination address of the second frame is the address of the second device. Alternatively, the sender address of the second frame is the address of the second device, and the second frame is a frame that does not request a response frame. The first time resource is allocated by the first device to the second device from the acquired TXOP.

[0324] Optionally, the transceiver unit 12 is further configured to receive a first frame from the second device if the duration between the end of the second frame and the end of the first time resource is greater than T. The first frame indicates that the second device has stopped using the first time resource.

[0325] Optionally, the first time resource is used for the transmission of Single User Physical Layer Protocol Data Units (PPDUs) on the uplink or for point-to-point P2P communication. A single-user trigger frame includes a first field and a second field. The first field indicates the remaining time resource of the TXOP, and the second field indicates the first time resource.

[0326] Optionally, the first frame carries first instruction information. The first instruction information indicates that the second device has stopped using the first time resource.

[0327] Optionally, the first frame may also carry second instruction information. The second instruction information indicates whether the second device requires additional time resources for data transmission.

[0328] Optionally, the A control field in the first frame includes first instruction information. Alternatively, the A control field in the first frame includes both first and second instruction information.

[0329] Optionally, the control identifier of the A control field is a first value. The first value indicates that the A control field contains first instruction information.

[0330] Optionally, the control identifier of the A control field is a second value. The second value indicates that the A control field is a command and status CAS control field. The first instruction information is carried in the reverse approval RDG subfield within the CAS control field. Alternatively, the first instruction information is carried in the RDG subfield within the CAS control field, and the second instruction information is carried in at least one bit in bits 4 through 8 within the CAS control field.

[0331] Optionally, the frame type field within the first frame indicates that the first frame is a control frame, and the frame subtype field within the first frame indicates that the first frame is a time resource return frame. A time resource return frame indicates that the second device has stopped using the first time resource.

[0332] In an alternative design, the transceiver / unit 12 is configured to transmit a second frame, where the destination address of the second frame is the address of a second device. The processing unit 11 is configured to decide to restore permission to use the transmit opportunity TXOP if the duration between the end of the second frame and the end of the first time resource is shorter than a pre-configured duration T. The first time resource is allocated by the first device to the second device from the obtained TXOP.

[0333] Optionally, the processing unit 11 is further configured to receive the first frame from the second device if the duration between the end of the second frame and the end of the first time resource is greater than T. The first frame indicates that the second device has stopped using the first time resource.

[0334] Optionally, the first time resource is used for the transmission of Single User Physical Layer Protocol Data Units (PPDUs) on the uplink or for point-to-point P2P communication. A single-user trigger frame includes a first field and a second field. The first field indicates the remaining time resource of the TXOP, and the second field indicates the first time resource.

[0335] Optionally, the first frame carries first instruction information. The first instruction information indicates that the second device has stopped using the first time resource.

[0336] Optionally, the first frame further carries second instruction information, which indicates whether the second device requires additional time resources for data transmission.

[0337] Optionally, the A control field in the first frame includes first instruction information. Alternatively, the A control field in the first frame includes both first and second instruction information.

[0338] Optionally, the control identifier of the A control field is a first value. The first value indicates that the A control field contains first instruction information.

[0339] Optionally, the control identifier of the A control field is a second value. The second value indicates that the A control field is a command and status CAS control field.

[0340] The first instruction information is carried in the reverse approval RDG subfield within the CAS control field.

[0341] Alternatively, the first instruction information may be carried in the RDG subfield within the CAS control field, and the second instruction information may be carried in at least one bit in bits 4 through 8 within the CAS control field.

[0342] Optionally, the frame type field within the first frame indicates that the first frame is a control frame, and the frame subtype field within the first frame indicates that the first frame is a time resource return frame. A time resource return frame indicates that the second device has stopped using the first time resource.

[0343] In an alternative design, processing unit 11 is configured to determine a third frame. The transceiver unit is configured to send the third frame to the second device. The third frame indicates that the first device has actively regained permission to use the transmit opportunity TXOP.

[0344] Optionally, the third frame is a block acknowledgment BA frame returned by the first device based on the data frame received from the second device. The BA control field within the BA frame indicates that the first device is actively restoring permission to use TXOP.

[0345] Optionally, the third frame is an aggregated frame, which is obtained by aggregating the fourth frame with the BA frame. The fourth frame indicates that the first device is actively regaining permission to use TXOP. The BA frame is generated by the first device based on the data frame received from the second device.

[0346] Optionally, the A control field in the fourth frame contains third instruction information. The third instruction information indicates that the first device actively regains permission to use TXOP.

[0347] Optionally, the control identifier of the A control field is a third value. The third value indicates that the A control field contains third instruction information.

[0348] Optionally, the frame type field in the third frame indicates that the third frame is a control frame, and the frame subtype field in the third frame indicates that the third frame is an active recovery frame. An active recovery frame indicates that the first device actively recovers permission to use the transmit opportunity TXOP.

[0349] Device 1 for restoring permission to use the transmission opportunity may, in correspondence, perform the steps in the above method embodiment, and it should be understood that the above operation or function of the unit in Device 1 for restoring permission to use the transmission opportunity is used separately to implement the corresponding operation performed by the first device in the above method embodiment. For the corresponding beneficial effects, please refer to the method embodiment. For brevity, further details will not be described again here.

[0350] Refer to Figure 25. The device that restores permission to use the transmission opportunity may alternatively be a second device or a chip within the second device, such as a Wi-Fi chip. As shown in Figure 25, the device that restores permission to use the transmission opportunity includes a processing unit 11 and a transceiver unit 12.

[0351] In one design, processing unit 11 is configured to determine a first frame. The first frame indicates that the second device has stopped using the first time resource. The first time resource is allocated to the second device by the first device from an acquired transmit opportunity TXOP. The first time resource is allocated to the second device by the first device using a single-user trigger frame.

[0352] Optionally, the first time resource is used for the transmission of Single User Physical Layer Protocol Data Units (PPDUs) on the uplink or for point-to-point P2P communication. A single-user trigger frame includes a first field and a second field. The first field indicates the remaining time resource of the TXOP, and the second field indicates the first time resource.

[0353] Optionally, the first frame carries first instruction information. The first instruction information indicates that the second device has stopped using the first time resource.

[0354] Optionally, the first frame may also carry second instruction information, which indicates whether the second device requires additional time resources for data transmission.

[0355] Optionally, the A control field in the first frame includes first instruction information. Alternatively, the A control field in the first frame includes both first and second instruction information.

[0356] Optionally, the control identifier of the A control field is a first value. The first value indicates that the A control field contains first instruction information.

[0357] Optionally, the control identifier of the A control field is a second value. The second value indicates that the A control field is a command and status CAS control field. The first instruction information is carried in the reverse approval RDG subfield within the CAS control field. Alternatively, the first instruction information is carried in the RDG subfield within the CAS control field, and the second instruction information is carried in at least one bit between bits 4 and 8 within the CAS control field.

[0358] Optionally, the frame type field within the first frame indicates that the first frame is a control frame, and the frame subtype field within the first frame indicates that the first frame is a time resource return frame. A time resource return frame indicates that the second device has stopped using the first time resource.

[0359] Optionally, if the first frame is a Quality of Service (QoS) null data frame, or if the first frame is a time resource return frame, and the end of the first frame is later than the end of the first time resource, and the start of the first frame is earlier than the end of the first time resource, the second device sends the first frame to the first device.

[0360] In an alternative design, the transceiver unit 12 is configured to receive or transmit a second frame. The second frame is a frame that does not request a response frame. If the duration between the end of the second frame and the end of the first time resource is shorter than a preset duration T, the second device does not transmit any further PPDUs.

[0361] Optionally, the second device further includes a processing unit 11. The processing unit 11 is configured to use a transceiver unit 12 to send a first frame to the first device if the duration between the end of the second frame and the end of the first time resource is greater than a preset duration T. The first frame indicates that the second device has stopped using the first time resource. The first time resource is allocated to the second device by the first device from the acquired TXOP.

[0362] Optionally, the first time resource is used for the transmission of Single User Physical Layer Protocol Data Units (PPDUs) on the uplink or for point-to-point P2P communication. A single-user trigger frame includes a first field and a second field. The first field indicates the remaining time resource of the TXOP, and the second field indicates the first time resource.

[0363] Optionally, the first frame carries first instruction information. The first instruction information indicates that the second device has stopped using the first time resource.

[0364] Optionally, the first frame further carries second instruction information, which indicates whether the second device requires additional time resources for data transmission.

[0365] Optionally, the A control field in the first frame includes first instruction information. Alternatively, the A control field in the first frame includes both first and second instruction information.

[0366] Optionally, the control identifier of the A control field is a first value. The first value indicates that the A control field contains first instruction information.

[0367] Optionally, the control identifier of the A control field is a second value. The second value indicates that the A control field is a command and status CAS control field.

[0368] The first instruction information is carried in the reverse approval RDG subfield within the CAS control field.

[0369] Alternatively, the first instruction information may be carried in the RDG subfield within the CAS control field, and the second instruction information may be carried in at least one bit in bits 4 through 8 within the CAS control field.

[0370] Optionally, the frame type field within the first frame indicates that the first frame is a control frame, and the frame subtype field within the first frame indicates that the first frame is a time resource return frame. A time resource return frame indicates that the second device has stopped using the first time resource.

[0371] Optionally, if the first frame is a Quality of Service (QoS) null data frame, or if the first frame is a time resource return frame, the second device is permitted to send the first frame to the first device if the end of the first frame is after the end of the first time resource and the start of the first frame is earlier than the end of the first time resource.

[0372] In an alternative design, the transceiver unit 12 is configured to receive a second frame from a first device. The processing unit 11 is configured to determine that the second device will not transmit any further PPDUs if the duration between the end of the second frame and the end of the first time resource is shorter than a preset duration T.

[0373] Optionally, the processing unit 11 is configured to decide to send the first frame to the first device using the transceiver unit 12 if the duration between the end of the second frame and the end of the first time resource is longer than a preset duration T. The first frame indicates that the second device has stopped using the first time resource. The first time resource is then allocated to the second device by the first device from the acquired TXOP.

[0374] Optionally, the first time resource is used for the transmission of Single User Physical Layer Protocol Data Units (PPDUs) on the uplink or for point-to-point P2P communication. A single-user trigger frame includes a first field and a second field. The first field indicates the remaining time resource of the TXOP, and the second field indicates the first time resource.

[0375] Optionally, the first frame carries first instruction information. The first instruction information indicates that the second device has stopped using the first time resource.

[0376] Optionally, the first frame may also carry second instruction information, which indicates whether the second device requires additional time resources for data transmission.

[0377] Optionally, the A control field in the first frame includes first instruction information. Alternatively, the A control field in the first frame includes both first and second instruction information.

[0378] Optionally, the control identifier of the A control field is a first value. The first value indicates that the A control field contains first instruction information.

[0379] Optionally, the control identifier of the A control field is a second value. The second value indicates that the A control field is a command and status CAS control field.

[0380] The first instruction information is carried in the reverse approval RDG subfield within the CAS control field.

[0381] Alternatively, the first instruction information may be carried in the RDG subfield within the CAS control field, and the second instruction information may be carried in at least one bit in bits 4 through 8 of the CAS control field.

[0382] Optionally, the frame type field within the first frame indicates that the first frame is a control frame, and the frame subtype field within the first frame indicates that the first frame is a time resource return frame. A time resource return frame indicates that the second device has stopped using the first time resource.

[0383] Optionally, if the first frame is a Quality of Service (QoS) null data frame, or if the first frame is a time resource return frame, the second device is permitted to send the first frame to the first device if the end of the first frame is after the end of the first time resource and the start of the first frame is earlier than the end of the first time resource.

[0384] In an alternative design, the processing unit 11 is configured such that when the second device receives a third frame from the first device, the second device decides not to use the transceiver unit 12 to transmit the data frame, or to retransmit the data frame k times using the transceiver unit 12. The third frame indicates that the first device has actively regained permission to use the transmit opportunity TXOP. k is an integer greater than 0.

[0385] Optionally, the third frame is a block acknowledgment BA frame returned by the first device based on the data frame received from the second device. The BA control field within the BA frame indicates that the first device is actively restoring permission to use TXOP.

[0386] Optionally, the third frame is an aggregate frame, which is obtained by aggregating the fourth frame with the BA frame. The fourth frame indicates that the first device is actively regaining permission to use TXOP. The BA frame is generated by the first device based on the data frame received from the second device.

[0387] Optionally, the A control field in the fourth frame contains third instruction information. The third instruction information indicates that the first device actively regains permission to use TXOP.

[0388] Optionally, the control identifier of the A control field is a third value. The third value indicates that the A control field contains third instruction information.

[0389] Optionally, the frame type field in the third frame indicates that the third frame is a control frame, and the frame subtype field in the third frame indicates that the third frame is an active recovery frame. An active recovery frame indicates that the first device actively recovers permission to use the transmit opportunity TXOP.

[0390] Device 1 for restoring permission to use the transmission opportunity may further perform the steps in the above method embodiment, and it should be understood that the above operation or function of the unit in Device 1 for restoring permission to use the transmission opportunity is separately used to implement the corresponding operation performed by the second device in the above method embodiment. For the corresponding beneficial effects, please refer to the method embodiment. For brevity, further details will not be described again here.

[0391] The above describes the first and second devices in the embodiments of the present application. The following describes possible product forms of the first and second devices. It should be understood that any form of product having the functionality of the first device in Figure 25, or any form of product having the functionality of the second device in Figure 25, or both, falls within the scope of protection of the embodiments of the present application. Furthermore, it should be understood that the following description is merely an example, and the product forms of the first and second devices in the embodiments of the present application are not limited thereto.

[0392] In a possible product configuration, the first and second devices in the embodiments of this application may be implemented using a common bus architecture.

[0393] For ease of explanation, Figure 26 shows a schematic diagram of the structure of a communication device 1000 according to one embodiment of the present invention. The communication device 1000 may be a first device, a second device, or a chip within the first device or the second device. Figure 26 shows only the main components of the communication device 1000. In addition to the processor 1001 and transceiver 1002, the communication device may further include a memory 1003 and an input / output device (not shown).

[0394] The processor 1001 is configured primarily to process communication protocols and communication data, control communication equipment, execute software programs, and process data within said software programs. The memory 1003 is configured primarily to store software programs and data. The transceiver 1002 may include a control circuit and an antenna. The control circuit is configured primarily to convert between baseband signals and radio frequency signals and to process radio frequency signals. The antenna is configured primarily to transmit and receive radio frequency signals in the form of electromagnetic waves. Input / output devices such as touchscreens, displays, and keyboards are configured primarily to receive data entered by the user and output data to the user.

[0395] 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 it is necessary to transmit data wirelessly, the processor 1001 performs baseband processing on the data to be transmitted and then outputs the baseband signal to the radio frequency circuit. After performing radio frequency processing on the baseband signal, the radio frequency circuit transmits the radio frequency signal in the form of electromagnetic waves through the 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.

[0396] In another implementation, the radio frequency circuitry and antenna may be located independently of the processor performing baseband processing. For example, in a distributed scenario, the radio frequency circuitry and antenna may be located separately and independently of the communication equipment.

[0397] The processor 1001, transceiver 1002, and memory 1003 may be connected via a communication bus.

[0398] In one design, the communication device 1000 may be configured to perform the functions of the first device in the method embodiment described above. The processor 1001 may be configured to perform step S102 in Figure 3, and / or step S202 in Figure 16, and / or step S302 in Figure 18, and / or step S401 in Figure 20, and / or another process of the technology described in this specification. The transceiver 1002 may be configured to perform step S101 in Figure 3, and / or step S201 in Figure 16, and / or step S301 in Figure 18, and / or step S402 in Figure 20, and / or another process of the technology described in this specification.

[0399] In an alternative design, the communication device 1000 may be configured to perform the function of the second device in the embodiment of the method described above. The processor 1001 may be configured to determine the first frame in step S101 of Figure 3, and / or step S202 of Figure 16, and / or step S302 of Figure 18, and / or step S402 of Figure 20, and / or another process of the technology described herein. The transceiver 1002 may be configured to transmit the first frame in step S101 of Figure 3, and / or step S201 of Figure 16, and / or step S301 of Figure 18, and / or step S401 of Figure 20, and / or another process of the technology described herein.

[0400] In any of the above designs, the processor 1001 may include a transceiver configured to implement receiving and transmitting functions. For example, the transceiver may be a transceiver circuit, interface, or interface circuit. The transceiver circuit, interface, or interface circuit configured to implement transmitting and receiving functions may be separate or integrated together. The transceiver circuit, interface, or interface circuit may be configured to read and write code / data. Alternatively, the transceiver circuit, interface, or interface circuit may be configured to transmit or transfer signals.

[0401] In any of the designs described above, the processor 1001 may store instructions. These instructions may be computer programs. The computer programs are executed on the processor 1001, thereby enabling the communication device 1000 to perform the methods described in any of the above embodiments of the method. The computer programs may be fixed on the processor 1001, in which case the processor 1001 may be implemented by hardware.

[0402] In some implementations, the communication device 1000 may include a circuit that implements the transmit, receive, or communicate functions described in the method embodiments described above. The processors and transceivers described herein may be mounted on 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 be alternatively manufactured using various IC technologies, such as complementary metal oxide semiconductors (CMOS), n-metal oxide semiconductors (NMOS), positive-channel metal oxide semiconductors (PMOS), bipolar junction transistors (BJTs), bipolar CMOS (BiCMOS), silicon germanium (SiGe), and gallium arsenide (GaAs).

[0403] The scope of communication devices described herein is not limited thereto, and the structure of communication devices is not limited by Figure 26. A communication device may be a standalone device or part of a larger device. For example, a communication device may be: (1) Independent integrated circuits (ICs), chips, or chip systems or subsystems; (2) A set comprising one or more ICs (optionally, the IC set may further include a storage component configured to store data and computer programs); (3) ASIC, for example, a modem; (4) Modules that can be incorporated into other devices; (5) Receivers, terminals, intelligent terminals, mobile phones, wireless devices, handheld devices, mobile units, in-vehicle devices, network devices, cloud devices, artificial intelligence devices, etc.; or (6) Another device, etc.

[0404] In one possible product configuration, the first and second devices in the embodiments of the present application may be implemented by a general-purpose processor.

[0405] A general-purpose processor implementing the first device includes a processing circuit and an input / output interface that is internally connected to the processing circuit and communicates with the processing circuit.

[0406] In a particular design, a general-purpose processor may be configured to perform the functions of the first device in the method embodiment described above. Specifically, the processing circuit is configured to perform step S102 in Figure 3, and / or step S202 in Figure 16, and / or step S302 in Figure 18, and / or step S401 in Figure 20, and / or another process of the technology described in this specification. The input / output interface is configured to perform step S101 in Figure 3, and / or step S201 in Figure 16, and / or step S301 in Figure 18, and / or step S402 in Figure 20, and / or another process of the technology described in this specification.

[0407] A general-purpose processor for implementing the second device includes a processing circuit and an input / output interface that is internally connected to the processing circuit and communicates with the processing circuit.

[0408] In one design, a general-purpose processor may be configured to perform the function of the second device in the embodiment of the method described above. Specifically, the processing circuit is configured to determine a first frame in step S101 in Figure 3, and / or step S202 in Figure 16, and / or step S302 in Figure 18, and / or step S40 in Figure 20, and / or another process of the technology described in this specification. The input / output interface is configured to transmit a first frame in step S101 in Figure 3, and / or step S201 in Figure 16, and / or step S301 in Figure 18, and / or step S402 in Figure 20, and / or another process of the technology described in this specification.

[0409] It should be understood that the communication devices in the various product forms described above have the function of either the first or second device in the above method embodiment, and can accordingly perform the steps in the above method embodiment and achieve the corresponding technical effects. For brevity, further details will not be explained here.

[0410] One embodiment of the present invention further provides a computer-readable storage medium for storing computer program code. When a processor executes the computer program code, the electronic device performs one of the methods of the above embodiments.

[0411] One embodiment of the present invention further provides a computer program product. When the computer program product is executed on a computer, the computer is enabled to perform any of the methods of the above embodiments.

[0412] One embodiment of the present invention further provides a communication device, which may exist in the form of a chip. The device's structure includes a processor and an interface circuit. The processor is configured to communicate with other devices through the interface circuit, enabling the device to perform any of the methods described in the above-described embodiments.

[0413] One embodiment of the present invention further provides a wireless communication system including a first device and a second device. The first and second devices can perform any method of the above embodiment.

[0414] Methods or algorithmic steps described in combination with the information disclosed herein may be implemented using hardware or using a processor by executing software instructions. Software instructions may include corresponding software modules. Software modules may be stored in random access memory (RAM), flash memory, erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), registers, hard disks, removable hard disks, compact disk read-only memory (CD-ROM), or other forms of storage media well known in the art. For example, the storage medium may be coupled to a processor, which can read information from or write information to the storage medium. Of course, the storage medium may be a component of the processor. The processor and storage medium may be located within an ASIC. Furthermore, the ASIC may be located within a core network interface device. Of course, the processor and storage medium may exist as discrete components within a core network interface device.

[0415] A person skilled in the art will recognize that, in one or more of the above examples, the functions described in this application may be implemented using hardware, software, firmware, or any combination thereof. If the functions are implemented by software, they may be stored in a computer-readable medium or transmitted as one or more instructions or codes within a computer-readable medium. Computer-readable mediums include computer-readable storage media and communication media. Communication media include media that facilitate the transmission of computer programs from one location to another. Storage media may be any available medium accessible to a general-purpose or special-purpose computer.

[0416] The individual implementations described above provide further details on the objectives, technical solutions, and beneficial effects of this application. It should be understood that these descriptions represent only specific implementations of this application and are not intended to limit the scope of protection. Any modifications, equivalent substitutions, improvements, etc., made based on the technical solutions of this application should fall within the scope of protection.

Claims

1. A way to restore permission to use the transmission opportunity: The steps include: a step in which the access point transmits a modified Multi-User Transmit Request (MU-RTS) frame to the station, the modified MU-RTS frame indicating that time resources are allocated to the station by the access point from acquired Transmit Opportunities (TXOP); A step in which the access point receives a Quality of Service (QoS) data frame or a QoS null data frame from the station, wherein the QoS data frame or the QoS null data frame includes an A control field, the A control field including a control identifier indicating that the A control field is a command and status (CAS) control field, and a reverse authorization (RDG) / further PPDU subfield indicating that the second device has stopped using the time resource; The access point recovers permission to use the TXOP based on the QoS data frame or the QoS null data frame, method.

2. The method according to claim 1, wherein the allocated time resources are used for the transmission of single-user physical layer protocol data units (PPDUs) on the uplink or for point-to-point (P2P) communication.

3. The method according to claim 1, wherein the modified MU-RTS frame includes a first field and a second field, the first field indicating the remaining time resources of the TXOP and the second field indicating the time resources allocated to the second device.

4. A way to restore permission to use the transmission opportunity: The station receives a modified Multi-User Transmit Request (MU-RTS) frame from the access point, the modified MU-RTS frame indicating that time resources are allocated to the station by the access point from acquired Transmit Opportunities (TXOP); A step in which the station determines a Quality of Service (QoS) data frame or a QoS null data frame, wherein the QoS data frame or the QoS null data frame includes an A control field, the A control field including a control identifier indicating that the A control field is a command and status (CAS) control field, and a reverse authorization (RDG) / further PPDU subfield indicating that the second device has stopped using the time resource; The process includes the step of the station transmitting the QoS data frame or the QoS null data frame to the access point. method.

5. The method according to claim 4, wherein the allocated time resources are used for the transmission of single-user physical layer protocol data units (PPDUs) on the uplink or for point-to-point (P2P) communication.

6. The method according to claim 4, wherein the modified MU-RTS frame includes a first field and a second field, the first field indicating the remaining time resources of the TXOP and the second field indicating the time resources allocated to the second device.

7. A communication device having a processor and memory, The memory is configured to store computer instructions; The processor executes the computer instructions stored in the memory so that the device can perform the method according to any one of claims 1 to 6. Communication device.

8. A computer-readable storage medium, wherein the computer-readable storage medium stores program instructions, and when the program instructions are executed on a computer, the computer is able to perform the method according to any one of claims 1 to 6.

9. A computer program product comprising program instructions, wherein when the program instructions are executed on a computer, the computer is enabled to perform the method according to any one of claims 1 to 6.

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