CN117424679A

CN117424679A - Communication method and communication device

Info

Publication number: CN117424679A
Application number: CN202210802022.4A
Authority: CN
Inventors: 于健; 阮卫; 郭宇宸; 淦明
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2022-07-08
Filing date: 2022-07-08
Publication date: 2024-01-19
Also published as: WO2024008025A1

Abstract

The application provides a communication method and a communication device, wherein the method comprises the following steps: the second communication device receives a first physical layer protocol data unit, PPDU, from a first communication device, the first PPDU comprising a data field comprising multicast data for a plurality of communication devices. The second communication device transmits a second PPDU at a first time and in a first frequency band, the second PPDU carrying a first MPDU, the first MPDU including first information for indicating that the data field is not correctly received, the first time being a time when a second communication device of the plurality of communication devices synchronously transmits the second PPDU, the second communication device being the communication device that does not correctly receive the data field, the first frequency band being a frequency band in which the second communication device synchronously transmits the second PPDU. The scheme can realize the resource utilization rate and the multicast data transmission efficiency.

Description

Communication method and communication device

Technical Field

The present application relates to the field of communications, and more particularly, to a communication method and a communication apparatus.

Background

Currently, in order to improve the reliability of multicast data transmission in a wireless local area network, an acknowledgement mechanism based on multicast data transmission is proposed. An Access Point (AP) transmits one or more multicast data To Stations (STAs) within a multicast group. After transmitting the multicast data, the AP may transmit a block acknowledgement request frame to STAs within the group one by one to acquire a block acknowledgement frame of each STA.

However, as wireless networks are popularized in production and life, the number of multicast members receiving multicast data also increases dramatically, and when the number of multicast members is large, the above-mentioned acknowledgement mechanism has a problem of large resource overhead and low transmission efficiency.

Disclosure of Invention

The embodiment of the application provides a communication method and a communication device, which are used for improving the resource utilization rate and the multicast data transmission efficiency.

In a first aspect, a communication method is provided, which may be performed by a STA or a module (e.g., a chip) configured with the STA.

The method comprises the following steps: receiving a first physical layer protocol data unit, PPDU, from a first communication device, the first PPDU comprising a data field, the data field comprising multicast data for a plurality of communication devices; a second PPDU is transmitted at a first time and in a first frequency band, the second PPDU carrying a first MPDU, the first MPDU including first information for indicating that the data field is not correctly received, the first time being a time when a second communication device of the plurality of communication devices synchronously transmits the second PPDU, the second communication device being the communication device that does not correctly receive the data field, the first frequency band being a frequency band in which the second communication device synchronously transmits the second PPDU.

According to this scheme, STAs in the STA group transmit the unacknowledged frame to the AP only if the data field is not correctly received, and the STA feeds back only the unacknowledged frame (i.e., the first MPDU) because the probability of not receiving the data field is small relative to the probability of receiving the data field, can reduce the STA power overhead and the radio resource overhead of correctly receiving the data field. And a plurality of STAs which do not correctly receive the data field send the non-acknowledgement frame at the same time and the same frequency, compared with a mode that different STAs send the non-acknowledgement frame at different radio resources (such as different time and/or different frequency), the cost of the radio resources can be further reduced, and the radio resource utilization rate is improved. The scheme provided by the application optimizes the retransmission mechanism of the multicast data and improves the efficiency of multicast data transmission.

With reference to the first aspect, in certain implementations of the first aspect, the first PPDU further includes second information, where the second information is used to indicate that the second communication device is required to transmit the first MPDU.

According to the scheme, the AP can inform the STA whether the multicast group needs to feed back the non-acknowledgement frame through the second information borne by the first PPDU, so that the AP and the STA can achieve consensus.

With reference to the first aspect, in certain implementations of the first aspect, the first time and the first PPDU are separated by a first duration, the first duration is predefined, or the first duration is preconfigured for the first communication device, or the first PPDU further includes information for indicating the first duration.

As an example and not by way of limitation, the first duration may be a short interframe space (SIFS) of 16 microseconds. Alternatively, the first duration may be a Priority IFS (PIFS) of 25 microseconds. Still alternatively, the first duration may be a distributed coordination function interframe space (distributed coordination function IFS, DIFS) of 34 microseconds. Or the first time period may be a value other than the IFS described above.

With reference to the first aspect, in certain implementations of the first aspect, the first frequency band is a transmission frequency band of the first PPDU, or the first PPDU further includes information for indicating the first frequency band.

According to the scheme, the STA can feed back the non-acknowledgement frame to the AP at the first moment of the first duration of the first PPDU interval and in the designated transmission frequency band, so that the STA can send the non-acknowledgement frame to the AP in the transmission frequency band of the first PPDU without carrying out channel idle detection, and the communication time delay is reduced.

With reference to the first aspect, in certain implementations of the first aspect, the method further includes: and receiving a third PPDU from the first communication device, the third PPDU carrying a second MPDU, the second MPDU including third information for triggering the second communication device to synchronously transmit the first MPDU.

According to the above scheme, the STA may be triggered to transmit the non-acknowledgement frame by the non-acknowledgement trigger frame (i.e., the second MPDU) transmitted by the AP, so that the STA may have enough data processing time to determine whether the data is successfully received. And the AP can send the unacknowledged trigger frame under the condition that the unacknowledged frame is needed, so that the flexibility of a feedback mechanism is improved.

With reference to the first aspect, in certain implementations of the first aspect, the first time and the third PPDU are separated by a second time period, the second time period being predefined, or the first time period being preconfigured for the first communication device; alternatively, the first PPDU or the second MPDU further includes information indicating the first duration.

With reference to the first aspect, in certain implementations of the first aspect, the first frequency band is a transmission frequency band of the third PPDU; alternatively, the first PPDU or the second MPDU further includes information indicating the first frequency band.

According to the scheme, the STA can feed back the non-acknowledgement frame to the AP at the first moment of the first duration of the third PPDU interval and in the appointed transmission frequency band, so that the STA can send the non-acknowledgement frame to the AP in the transmission frequency band of the third PPDU without carrying out channel idle detection, and the communication time delay is reduced.

With reference to the first aspect, in certain implementations of the first aspect, a frame format of the second MPDU is the same as a frame format of a trigger frame or a block acknowledgement request frame.

According to the scheme, the second MPDU can multiplex the frame format of the trigger frame or the block acknowledgement request frame, so that the standardization progress is improved.

With reference to the first aspect, in certain implementation manners of the first aspect, the trigger frame includes a user information field, where the user information field includes association identifiers corresponding to multicast addresses of the plurality of communication devices, or the association identifier in the user information field is a predetermined value.

With reference to the first aspect, in certain implementations of the first aspect, a frame format of the first MPDU is the same as a frame format of a quality of service null frame, a frame format of an acknowledgement frame, or a frame format of a block acknowledgement frame.

With reference to the first aspect, in certain implementations of the first aspect, the physical layer parameters of the second PPDU are indicated by one or more of:

The physical layer parameters of the protocol predefined manner, indicated by the first communication device, or the second PPDU are the same as the physical layer processing parameters of the first PPDU;

the physical layer parameters include one or more parameters of a scrambling code initialization state, a coding mode or a modulation mode.

According to the scheme, the STA can achieve consensus on the physical layer parameters of the second PPDU, so that a plurality of STAs synchronously send the same second PPDU.

In a second aspect, a communication method is provided, which may be performed by an AP or a module (e.g., a chip) configured (or for) the AP.

The method comprises the following steps: transmitting a first physical layer protocol data unit, PPDU, the first PPDU comprising a data field comprising multicast data for a plurality of communication devices; a second PPDU is received at a first time and at a first frequency band, the second PPDU including a first MPDU, the first MPDU including first information indicating that the data field is not correctly received, the first time being a time at which a second communication device of the plurality of communication devices synchronously transmits the first MPDU, the second communication device being the communication device that did not correctly receive the data field, the first frequency band being a frequency band at which the second communication device synchronously transmits the second PPDU.

With reference to the second aspect, in some implementations of the second aspect, the first PPDU further includes second information, where the second information is used to indicate that the second communication device is required to transmit the first MPDU.

With reference to the second aspect, in some implementations of the second aspect, the first time and the first PPDU are separated by a first duration, the first duration is predefined, or the first duration is preconfigured for the first communication device, or the first PPDU further includes information for indicating the first duration.

With reference to the second aspect, in some implementations of the second aspect, the first frequency band is a transmission frequency band of the first PPDU, or the first PPDU further includes information for indicating the first frequency band.

With reference to the second aspect, in certain implementations of the second aspect, the method further includes:

and transmitting a third PPDU, wherein the third PPDU carries a second MPDU, and the second MPDU comprises third information which is used for triggering the second communication device to synchronously transmit the first MPDU.

With reference to the second aspect, in certain implementations of the second aspect, the first time and the third PPDU are separated by a second time period, the second time period being predefined, or the first time period being preconfigured for the first communication device; alternatively, the first PPDU or the second MPDU further includes information indicating the first duration.

With reference to the second aspect, in certain implementations of the second aspect, the first frequency band is a transmission frequency band of the third PPDU; alternatively, the first PPDU or the second MPDU further includes information indicating the first frequency band.

With reference to the second aspect, in some implementations of the second aspect, a frame format of the second MPDU is the same as a frame format of a trigger frame or a frame format of a block acknowledgement request frame.

With reference to the second aspect, in certain implementations of the second aspect, the trigger frame includes a user information field, where the user information field includes an association identifier corresponding to a multicast address of the plurality of communication devices, or the association identifier in the user information field is a predetermined value.

With reference to the second aspect, in some implementations of the second aspect, a frame format of the first MPDU is the same as a frame format of a quality of service null frame, a frame format of an acknowledgement frame, or a frame format of a block acknowledgement frame.

With reference to the second aspect, in certain implementations of the second aspect, the physical layer parameters of the second PPDU are indicated by one or more of:

the physical layer parameters of the protocol predefined manner, indicated by the first communication device, or the second MPDU are the same as the physical layer processing parameters of the first PPDU;

In a third aspect, a communications apparatus is provided, where the apparatus can include modules, either hardware circuitry or software, or a combination of hardware circuitry and software implementation, that perform the methods/operations/steps/actions described in the first aspect. In one design, the apparatus includes: a transceiver unit for receiving a first physical layer protocol data unit, PPDU, from a first communication device, the first PPDU comprising a data field, the data field comprising multicast data for a plurality of communication devices; a processing unit for determining that the data field was not received correctly; the transceiver unit is further configured to transmit a second PPDU at a first time and in a first frequency band, where the second PPDU carries a first MPDU, the first MPDU including first information, where the first information is used to indicate that the data field is not correctly received, the first time is a time when a second communication device of the plurality of communication devices synchronously transmits the second PPDU, the second communication device is the communication device that does not correctly receive the data field, and the first frequency band is a frequency band in which the second communication device synchronously transmits the second PPDU.

With reference to the third aspect, in some implementations of the third aspect, the first PPDU further includes second information, where the second information is used to indicate that the second communication device is required to transmit the first MPDU.

With reference to the third aspect, in some implementations of the third aspect, the first time and the first PPDU are separated by a first duration, the first duration is predefined, or the first duration is preconfigured for the first communication device, or the first PPDU further includes information for indicating the first duration.

With reference to the third aspect, in some implementations of the third aspect, the first frequency band is a transmission frequency band of the first PPDU, or the first PPDU further includes information for indicating the first frequency band.

With reference to the third aspect, in some implementations of the third aspect, the transceiver is further configured to receive a third PPDU from the first communication device, where the third PPDU carries a second MPDU, and the second MPDU includes third information, where the third information is configured to trigger the second communication device to synchronously send the first MPDU.

With reference to the third aspect, in certain implementations of the third aspect, the first time and the third PPDU are separated by a second time period, the second time period being predefined, or the first time period being preconfigured for the first communication device; alternatively, the first PPDU or the second MPDU further includes information indicating the first duration.

With reference to the third aspect, in certain implementations of the third aspect, the first frequency band is a transmission frequency band of the third PPDU; alternatively, the first PPDU or the second MPDU further includes information indicating the first frequency band.

With reference to the third aspect, in some implementations of the third aspect, a frame format of the second MPDU is the same as a frame format of a trigger frame or a block acknowledgement request frame.

With reference to the third aspect, in some implementations of the third aspect, the trigger frame includes a user information field, where the user information field includes association identifiers corresponding to multicast addresses of the plurality of communication devices, or the association identifiers in the user information field are predetermined values.

With reference to the third aspect, in some implementations of the third aspect, a frame format of the first MPDU is the same as a frame format of a quality of service null frame, a frame format of an acknowledgement frame, or a frame format of a block acknowledgement frame.

With reference to the third aspect, in certain implementations of the third aspect, the physical layer parameters of the second PPDU are indicated by one or more of:

In a fourth aspect, a communications apparatus is provided, where the apparatus can include means for performing the method/operation/step/action described in the fourth aspect, where the means can be implemented by hardware circuitry, software, or a combination of hardware circuitry and software. In one design, the apparatus includes: a transceiver unit configured to transmit a first physical layer protocol data unit PPDU, the first PPDU including a data field including multicast data of a plurality of communication devices; the transceiver unit is further configured to receive a second PPDU at a first time and at a first frequency band, the second PPDU including a first MPDU, the first MPDU including first information indicating that the data field is not correctly received, the first time being a time when a second communication device of the plurality of communication devices synchronously transmits the first MPDU, the second communication device being the communication device that did not correctly receive the data field, the first frequency band being a frequency band in which the second communication device synchronously transmits the second PPDU. Optionally, the communication device further comprises a processing unit, and the processing unit is configured to determine that the multicast data transmission fails.

With reference to the fourth aspect, in some implementations of the fourth aspect, the first PPDU further includes second information, where the second information is used to indicate that the second communication device is required to transmit the first MPDU.

With reference to the fourth aspect, in some implementations of the fourth aspect, the first time and the first PPDU are separated by a first duration, the first duration is predefined, or the first duration is preconfigured for the first communication device, or the first PPDU further includes information for indicating the first duration.

With reference to the fourth aspect, in some implementations of the fourth aspect, the first frequency band is a transmission frequency band of the first PPDU, or the first PPDU further includes information for indicating the first frequency band.

With reference to the fourth aspect, in some implementations of the fourth aspect, the transceiver unit is further configured to send a third PPDU, where the third PPDU carries a second MPDU, and the second MPDU includes third information, where the third information is used to trigger the second communication device to send the first MPDU synchronously.

With reference to the fourth aspect, in certain implementations of the fourth aspect, the first time and the third PPDU are separated by a second time period, the second time period being predefined, or the first time period being preconfigured for the first communication device; alternatively, the first PPDU or the second MPDU further includes information indicating the first duration.

With reference to the fourth aspect, in some implementations of the fourth aspect, the first frequency band is a transmission frequency band of the third PPDU; alternatively, the first PPDU or the second MPDU further includes information indicating the first frequency band.

With reference to the fourth aspect, in some implementations of the fourth aspect, a frame format of the second MPDU is the same as a frame format of a trigger frame or a frame format of a block acknowledgement request frame.

With reference to the fourth aspect, in some implementations of the fourth aspect, the trigger frame includes a user information field, where the user information field includes an association identifier corresponding to a multicast address of the plurality of communication devices, or the association identifier in the user information field is a predetermined value.

With reference to the fourth aspect, in some implementations of the fourth aspect, a frame format of the first MPDU is the same as a frame format of a quality of service null frame, a frame format of an acknowledgement frame, or a frame format of a block acknowledgement frame.

With reference to the fourth aspect, in some implementations of the fourth aspect, the physical layer parameters of the second PPDU are indicated by one or more of:

In a fifth aspect, a communication device is provided that includes a processor. The processor may implement the method of the first aspect and any one of the possible implementations of the first aspect. Optionally, the communications apparatus further comprises a memory, the processor coupled to the memory and operable to execute instructions in the memory to implement the method of the first aspect and any possible implementation of the first aspect. Optionally, the communication device further comprises a communication interface, and the processor is coupled to the communication interface. In the embodiments of the present application, the communication interface may be a transceiver, a pin, a circuit, a bus, a module, or other types of communication interfaces, without limitation.

In a sixth aspect, a communication device is provided that includes a processor. The processor may implement the method of the second aspect described above and any one of the possible implementations of the second aspect. Optionally, the communications apparatus further comprises a memory, the processor being coupled to the memory and operable to execute instructions in the memory to implement the method of the second aspect and any one of the possible implementations of the second aspect. Optionally, the communication device further comprises a communication interface, and the processor is coupled to the communication interface.

In one implementation, the communication apparatus is a communication device. When the communication apparatus is a communication device, the communication interface may be a transceiver, or an input/output interface.

In another implementation, the communication apparatus is a chip configured in a communication device. When the communication device is a chip configured in a terminal apparatus, the communication interface may be an input/output interface.

Alternatively, the transceiver may be a transceiver circuit. Alternatively, the input/output interface may be an input/output circuit.

In a seventh aspect, there is provided a processor comprising: input circuit, output circuit and processing circuit. The processing circuit is configured to receive a signal via the input circuit and transmit a signal via the output circuit, such that the processor performs the first or second aspect and the method in any one of the possible implementations of the first or second aspect.

In a specific implementation process, the processor may be one or more chips, the input circuit may be an input pin, the output circuit may be an output pin, and the processing circuit may be a transistor, a gate circuit, a flip-flop, various logic circuits, and the like. The input signal received by the input circuit may be received and input by, for example and without limitation, a receiver, the output signal may be output by, for example and without limitation, a transmitter and transmitted by a transmitter, and the input circuit and the output circuit may be the same circuit, which functions as the input circuit and the output circuit, respectively, at different times. The embodiments of the present application do not limit the specific implementation manner of the processor and the various circuits.

In an eighth aspect, there is provided a computer program product comprising: a computer program (which may also be referred to as code, or instructions) which, when executed, causes a computer to perform the method of the first or second aspect and any one of the possible implementations of the first or second aspect.

In a ninth aspect, there is provided a computer readable storage medium storing a computer program (which may also be referred to as code, or instructions) which, when run on a computer, causes the computer to perform the method of the first or second aspect and any one of the possible implementations of the first or second aspect.

In a tenth aspect, there is provided a communication system comprising at least one of the communication apparatus provided in the third or fifth aspect and at least one of the communication apparatus provided in the fourth or sixth aspect.

Drawings

Fig. 1 is a schematic diagram of a communication system provided in an embodiment of the present application;

FIG. 2 is a schematic diagram of an acknowledgement mechanism provided by an embodiment of the present application;

FIG. 3 is a schematic flow chart of a communication method provided by an embodiment of the present application;

Fig. 4 is a schematic diagram of a frame structure of a first PPDU provided in an embodiment of the present application;

fig. 5 is a schematic diagram of a frame spacing between a first PPDU and a second PPDU provided in an embodiment of the present application;

FIG. 6 is a schematic diagram of an acknowledgement frame provided by an embodiment of the present application;

FIG. 7 is a schematic diagram of a block acknowledgement frame provided by an embodiment of the present application;

fig. 8 is a schematic diagram of a quality of service null frame provided in an embodiment of the present application;

fig. 9 is a schematic diagram of an inter-frame spacing between PPDUs provided in an embodiment of the present application;

FIG. 10 is a schematic diagram of a non-acknowledgement trigger frame provided in an embodiment of the present application;

FIG. 10a is a schematic diagram of a user information list provided by an embodiment of the present application;

FIG. 11 is a schematic diagram of a block acknowledgement request frame provided by an embodiment of the present application;

FIG. 12 is a schematic block diagram of a communication device provided by an embodiment of the present application;

fig. 13 is another schematic structural diagram of a communication device provided in an embodiment of the present application.

Detailed Description

The technical solutions in the present application will be described below with reference to the accompanying drawings.

In the embodiment of the present application, "/" may indicate that the associated object is an "or" relationship, for example, a/B may indicate a or B; "and/or" may be used to describe that there are three relationships associated with an object, e.g., a and/or B, which may represent: there are three cases, a alone, a and B together, and B alone, wherein a, B may be singular or plural. In order to facilitate description of the technical solutions of the embodiments of the present application, in the embodiments of the present application, the words "first", "second", and the like may be used for distinction. The terms "first," "second," and the like do not necessarily denote any order of quantity or order of execution, nor do the terms "first," "second," and the like. In this application embodiment, the terms "exemplary" or "such as" and the like are used to denote examples, illustrations, or descriptions, and any embodiment or design described as "exemplary" or "such as" should not be construed as preferred or advantageous over other embodiments or designs. The use of the word "exemplary" or "such as" is intended to present the relevant concepts in a concrete fashion to facilitate understanding. In the embodiments of the present application, at least one (seed) may also be described as one (seed) or a plurality of (seed), and the plurality of (seed) may be two (seed), three (seed), four (seed) or more (seed), which is not limited in this application.

The technical scheme provided by the embodiment of the application can be applied to wireless local area networks (wireless local area network, WLAN) or other systems requiring multicast communication.

Fig. 1 is a schematic diagram of a communication system 100 suitable for use in embodiments of the present application. The communication system 100 may include at least one AP, such as AP1, AP2, and AP3 shown in fig. 1. The communication system 100 may also include at least one STA, such as STA1, STA2, and STA3 shown in fig. 1. The scheme provided by the embodiment of the application can be suitable for multicast communication between the AP and a plurality of STAs, can also be suitable for multicast communication between the AP and a plurality of APs, and can also be suitable for multicast communication between the STAs and a plurality of STAs. In the embodiment of the present application, multicast communication between an AP and a plurality of STAs is described as an example.

Multicast (groupcast) in the embodiments of the present application includes broadcast (broadcast) and multicast (multicast). The AP and the STA in the embodiments of the present application refer to basic logic entities in a wireless local area network, where the AP is a network-side device capable of providing wireless signal transceiving services for the STA, and by way of example, the AP may include, but is not limited to, a communication server, a router, a switch, a bridge, a computer, and the like. The STA may be a terminal device including a WLAN interface, and illustratively, the STA may include, but is not limited to, a user terminal (e.g., a mobile phone, a tablet computer, a computer, etc.) or a smart terminal in an application scenario of a smart home, a smart factory, etc. The specific implementation forms of the AP and STA are not limited in this application. Currently, in order to improve the reliability of multicast data transmission in a wireless local area network, an acknowledgement mechanism based on multicast data transmission is proposed. The AP transmits one or more multicast data to STAs within the multicast group. After transmitting the multicast data, the AP may transmit a block acknowledgement request frame to STAs within the group one by one to acquire a block acknowledgement frame of each STA.

For example, as shown in fig. 2, the AP may transmit 3 times multicast data to a multicast group in which STA1, STA2, and STA3 receive the multicast data from the AP. After the third transmission of the multicast data, the AP may transmit a block acknowledgement request, such as block acknowledgement request frame 1, to instruct STA1 to feed back the block acknowledgement frame. STA1 receives the block acknowledgement request frame 1 and sends a block acknowledgement frame 1 to the AP to feed back whether multicast data is received correctly. The AP sequentially transmits block acknowledgement request frames 2 and 3 to STA2 and STA3, respectively, and STA2 and STA3 transmit block acknowledgement frames 2 and 3 to the AP, respectively. So that the AP can learn whether each STA successfully receives the multicast data, thereby determining whether the multicast data needs to be retransmitted.

In the above acknowledgement mechanism, the AP needs to send a block acknowledgement request frame to STAs in the multicast group one by one, and the STAs feed back the acknowledgement frame one by one. As wireless networks are popular in production and life, the number of multicast members receiving multicast data also increases dramatically, such as terminals in conference room scenarios that may require hundreds of parameter personnel to send the multicast data. The adoption of the acknowledgement mechanism has the advantages of high resource overhead and low transmission efficiency.

The application proposes that whether the multicast data is successfully transmitted or not can be informed to the AP by the STA which does not correctly receive the multicast data in the mode of simultaneously and co-frequency transmitting the non-acknowledgement frame. The method can reduce the cost of feedback resources and the power consumption cost of the STA for correctly receiving the multicast data by simultaneously feeding back the non-acknowledgement frames in the same frequency by the STA, and can improve the resource utilization rate and the efficiency of a multicast feedback mechanism.

Fig. 3 is a schematic flowchart of a communication method 300 provided in the embodiment of the present application, where the interaction between an AP (i.e. one example of a first communication device) and STA1 and STA2 (i.e. STA1 and STA2 are respectively one example of a second communication device) is taken as an example in the example of fig. 3, and it should be understood that the present application is not limited thereto, and that the functions of the AP or STA shown in fig. 3 may be implemented by other communication devices or communication devices (such as a chip, a chip system, etc.) in a specific implementation.

S301, the AP transmits a first physical protocol data unit (physical protocol data unit, PPDU) including a data field including multicast data of a plurality of STAs.

Accordingly, the plurality of STAs receives the first PPDU. The plurality of STAs are STAs in the same STA multicast group, and the plurality of STAs receiving the first PPDU may be referred to as a STA group, and include at least STA1 and STA2 shown in fig. 3, and may further include other STAs not shown in fig. 3, which is not limited in this application.

The first PPDU includes one or more Signal (SIG) fields. The one or more signaling fields may include, for example, one or more of a universal signaling (U-SIG) field, an XT-SIG field, or an XT-SIG2 field. Where XT may be an identification number of a standard protocol version used to identify a generation of standard protocols. Alternatively, the identification number of the standard protocol version may be represented by another representation, for example, the identification number may be NG, which represents the Next Generation (NG) standard protocol, or may be another identification number, which is not limited in this application.

Optionally, the one or more signaling fields include sender identification information and receiver identification information of the first PPDU.

The sender identification information may be, for example, a MAC address of the AP, for example, a full MAC address of 48 bits of the AP, or a partial MAC address of less than 48 bits. Still alternatively, the sender identification information may be a basic service set Color (basic service set Color, BSS Color), which is not limited in this application. The receiver identification information may be part or all of the MAC address of the multicast group, or may be an association identification or a partial association identification of the multicast group. The present application is not limited in this regard.

The sender identification information and the receiver identification information are carried in the signaling field of the first PPDU, so that even if the STA in the multicast group does not successfully decode the data field in the first PPDU, the STA can determine the sender and the receiver of the PPDU, thereby feeding back the unsuccessful received data field to the sender AP. Compared with the sender identification information and the receiver identification information carried in the MAC frame of the data field, the probability that the STA cannot know the sender and the receiver of the data due to the fact that the STA does not successfully decode the data field can be reduced.

Optionally, the first PPDU includes second information for indicating that the STA that does not correctly receive the data field in the first PPDU is required to feedback the first media intervention control (medium access control, MAC) protocol data unit (MAC protocol data unit, MPDU).

The first MPDU may be referred to as a non-acknowledgement frame, and the STAs in the STA group determine, according to the second information in the first PPDU, that the non-acknowledgement frame needs to be fed back if the data field is not correctly received. The second information may in particular be included in one or more of the signalling fields described above.

One or more MPDUs in the data field of the first PPDU, for an STA in the STA group, if the STA does not correctly receive at least one MPDU in the data field of the first PPDU, the STA does not correctly receive the data field. Or, the data field of the first PPDU includes a plurality of MPDUs, and for one STA in the STA group, if the number of MPDUs in the data field of the first PPDU is not correctly received by the STA is greater than or equal to a threshold value, the STA does not correctly receive the data field. And the STA in the STA group which does not receive the data field of the first PPDU sends a non-acknowledgement frame to the AP according to the second information in the first PPDU so as to inform the AP that the data field is not successfully received.

For an AP, at least one STA in the group of STAs does not correctly receive the data field of the first PPDU, and considers the multicast data transmission to be failed. Thus, if the AP receives a non-acknowledgement frame from at least one STA, the AP will send the multicast data to the STA group again, retransmitting the multicast data.

Optionally, the one or more signaling fields further include one or more of:

fountain code flag (fountain code flag), hybrid automatic repeat request (hybrid automatic repeat request, HARQ) indication, retransmission version number, or cyclic redundancy check (cyclic redundancy check, CRC) field.

The fountain code flag bit is used for indicating whether the PPDU transmission adopts fountain code coding or not. The hybrid automatic repeat request (hybrid automatic repeat request, HARQ) indicates whether HARQ transmission is used. The retransmission version number is used to indicate whether the current transmission is a primary transmission (which may be referred to as an initial transmission or a new transmission) or a retransmission (which may be referred to as a retransmission). For example, the retransmission version number may include 1 bit indicating 1 or 0 through the 1 bit to inform the STA group whether the current transmission is a new transmission or a retransmission. For another example, the retransmission version number may include a plurality of bits to indicate whether the current transmission is a new transmission or a number of retransmissions, e.g., the retransmission version number may include 2 bits to indicate whether the current transmission is a new transmission or a number of retransmissions by indicating 0, 1, 2, 3, respectively. But the present application is not limited thereto. The CRC field is used for the STA to check whether the signaling field is received correctly.

Illustratively, the first PPDU may include a legacy short training field (short training field, STF) and a long training field (long training field, LTF), i.e., legacy STF, L-STF and legacy long training field (legacy LTF, L-STF), as shown in fig. 4. The signaling field in the first PPDU may include a legacy signaling (L-SIG) field, a legacy L-SIG (RL-SIG) field, a U-SIG, and an XT-SIG as shown in fig. 4.

The XT-SIG may include a XT-SIG2 flag bit indicating whether or not the XT-SIG2 is present in the first PPDU, and if the flag bit indicates that the XT-SIG2 is present, a signaling field of the first PPDU may also include the XT-SIG2. The XT-SIG2 may include the sender identification information (e.g., the transmission address (transmitter address, TA) shown in fig. 4), the receiver identification information (e.g., the Reception Address (RA) shown in fig. 4), the second information (e.g., the non-acknowledgement (NACK required) indication shown in fig. 4), the fountain code flag, the retransmission version, the CRC field, etc. described above. But the application is not limited thereto, and the information such as the sender identification information, the receiver identification information, the second information, the fountain code flag bit, the retransmission version, etc. may be included in the U-SIG or the XT-SIG, or the above information may be distributed in one or more of the U-SIG, the XT-SIG, or the XT-SIG.

As shown in fig. 4, the first PPDU may further include short and long training fields of the XT version, that is, XT-STF and XT-LTF, and a data field and Packet Extension (PE) field.

S302, STA1 and STA2 transmit, at a first time and in a first frequency band, a second PPDU carrying a first MPDU including first information indicating that the data field is not received correctly.

STA1 and STA2 are STAs in the STA group that do not successfully receive the data field. The first time is a time when the STA in the STA group which does not correctly receive the data field synchronously transmits the second PPDU, and the first frequency band is a frequency band when the STA in the STA group which does not correctly receive the data field synchronously transmits the second PPDU.

And the STA in the STA group receives the first PPDU and decodes the first PPDU, and if the STA group does not correctly receive the STA synchronization (namely, the same time and the same frequency) of the data field, a second PPDU carrying a non-acknowledgement frame (namely, a first MPDU) is sent to the AP. For example, if STA1 and STA2 in the STA group do not successfully receive the data field in the first PPDU, both STA1 and STA2 transmit the second PPDU at the first time and in the same frequency band (i.e., the first frequency band), where the second PPDU includes a non-acknowledgement frame. The second PPDUs sent by the STA1 and the STA2 are identical, that is, the content of the first MPDU carried by the second PPDU is identical, and the physical layer parameters of the second PPDU are identical, so that the second PPDUs from the two STAs are coherently superimposed in the wireless channel, and the AP can receive the superimposed second PPDU in the first frequency band. According to the scheme, the STA only transmits the unacknowledged frame to the AP under the condition that the data field is not correctly received, and because the probability that the STA does not correctly receive the data field is smaller than the probability that the data field is correctly received in most scenes, only feeding back the unacknowledged frame can reduce the power cost of the STA and the cost of radio resources. And a plurality of STAs which do not correctly receive the data field send non-acknowledgement frames at the same time and in the same frequency, so that the cost of wireless resources can be further reduced, and the resource utilization rate can be improved.

In the example shown in fig. 3, a case in which a plurality of STAs including STA1 and STA2 do not successfully receive the data field is described as an example, in which, in a specific implementation, if only one STA in the STA group does not successfully receive the data field, the STA sends the second PPDU at the first time and on the first frequency band. And if the STAs in the STA group all successfully receive the data field, the STAs in the STA group all do not send the second PPDU.

Alternatively, the frame format of the first MPDU may be the same as the frame format of an acknowledgement frame, a block acknowledgement frame, or a quality of service null frame.

For example, the first MPDU may multiplex the frame format of the acknowledgement frame as shown in fig. 6, e.g., the type and subtype of the first MPDU, i.e., the non-acknowledgement frame, may be the same as the type and subtype of the acknowledgement frame, e.g., type 01, subtype 1101. The unacknowledged frame may include a frame control field, a duration field, a receive address field, and a frame check sequence (frame check sequence, FCS) as shown in fig. 6.

As another example, the first MPDU may multiplex the frame format of the block acknowledgement frame as shown in fig. 7, e.g., the type and subtype of the first MPDU, i.e., the non-acknowledgement frame, may be the same as the type and subtype of the acknowledgement frame, e.g., type 01, subtype 1001. The unacknowledged frame may include a frame control field, a duration field, a receive address field, a transmit address field, a block acknowledgement (block acknowledge, BA) control field, a block acknowledgement information field, and an FCS as shown in fig. 7. Wherein, the BA control field comprises a BA type field. For example, the MAC frame may be indicated as a non-acknowledgement frame by one of the BA type indications 12 to 15, and/or the block acknowledgement information may be set to a preset value to indicate that the MAC frame is a non-acknowledgement frame. The BA control field may further include one or more of a memoryless reserved field, a memoryless configuration tag field, a management acknowledgement field, and flow identification (traffic identifier, TID) Information (INFO) as shown in fig. 7, or the BA control field may further include other fields not shown in fig. 7, which are not limited in this application.

When the non-acknowledgement frame adopts the frame format of the block acknowledgement frame, the content of each field in the non-acknowledgement frame sent by different STAs in the multicast group is the same, where the sending address is the same address, for example, the sending address may be a multicast address, but the application is not limited thereto.

As another example, the first MPDU may multiplex the frame format of a quality of service (quality of service, qoS) Null (Null) frame as shown in fig. 8, or may be a QoS Null frame, and the STA informs the AP that the data field is not properly received by transmitting the QoS Null frame as a non-acknowledgement frame. As shown in fig. 7, the QoS Null frame is of type 10 and subtype 1100, and includes a frame control field, a duration field, an address field (e.g., address 1 to address 4), a sequence control field, a quality of service control field, a high throughput control field, and an FCS.

The above is an example of the first MPDU provided by the present application, and it should be understood that the present application is not limited thereto, and the frame format of the first MPDU may be a frame format specific to a non-acknowledgement frame, and may be different from the frame format of a MAC frame for other purposes. As the type and/or subtype of the first MPDU may be different from the type and/or subtype of the MAC frame for other uses, and the field composition of the first MPDU may be different from the field composition of the MAC frame for other uses.

STA1 and STA2 may transmit a second PPDU carrying the first MPDU after a first period of time after the first PPDU, or STA1 and STA2 may transmit a second PPDU carrying the first MPDU after a second period of time after receiving a third PPDU from the trigger frame of the AP. The two embodiments are described below.

In a first embodiment, the first time is separated from the first PPDU by a first duration.

In this embodiment, STAs in the STA group that do not correctly receive the data field transmit a second PPDU carrying a non-acknowledgement frame after a first duration (i.e., a first time) after the end time of the first PPDU.

Illustratively, the first duration is predefined, as may be predefined by a protocol. Alternatively, the first duration may be preconfigured by the AP, such as the AP informing STAs in the group of STAs of the first duration before transmitting the first PPDU. Or, the first PPDU further includes information for indicating the first duration, and the STA acquires the first duration from the received first PPDU. The first duration may be included as the XT-SIG or XT-SIG2 in the first PPDU.

The first duration may be referred to as an inter-frame space (IFS) X1 between the first PPDU and the second PPDU, for example, as shown in fig. 5, the IFS of the interval between the end time of the first PPDU and the start time of the second PPDU is the first duration X1, and the first duration may be a short interframe space (SIFS) of 16 microseconds. Alternatively, the first duration may be a Priority IFS (PIFS) of 25 microseconds. Still alternatively, the first duration may be a distributed coordination function interframe space (distributed coordination function IFS, DIFS) of 34 microseconds. Or the first duration may be a value other than the IFS described above, which is not limited in this application.

Optionally, the first frequency band is a transmission frequency band of the first PPDU, or the first PPDU further includes information for indicating the first frequency band.

For example, as shown in fig. 5, the first frequency band may be a transmission frequency band of the first PPDU. STA1 and STA2 do not correctly receive the data field in the first PPDU, and after receiving the first duration X1 of the first PPDU, STA1 and STA2 send a second PPDU carrying a non-acknowledgement frame on the same bandwidth as the first PPDU on the transmission frequency band of the first PPDU. Alternatively, the XT-SIG, XT-SIG2, or U-SIG in the first PPDU may include information indicating the first frequency band, and STA1 and STA2 transmit the second PPDU in the first frequency band indicated by the first PPDU.

The MAC layers of STA1 and STA2 generate a first MPDU of the same format and the same content, and a PPDU of the same format and the same content is employed in the physical layer, for example, the second PPDU may be a non-high throughput (non-HT) PPDU. And physical layer parameters of the second PPDU are the same. Optionally, the physical layer parameters of the second PPDU are indicated by one or more of:

the physical layer parameters of the protocol predefined manner, indicated by the AP, or the second PPDU are the same as the physical layer processing parameters of the first PPDU,

the physical layer parameter includes one or more parameters of a scrambling code initialization state, a coding mode or a modulation mode, and the physical layer parameter indicated by the AP may specifically be indicated by information in the first PPDU, or may be indicated by the AP to the STA group before sending the first PPDU.

For example, the scrambling code initialization state of the second PPDU may be the same as that of the first PPDU, and the coding and modulation scheme may be predefined by a binary phase shift keying (binary phase shift keying, BPSK) modulation scheme and a coding scheme with a 1/2 code rate. But the present application is not limited thereto.

In a second embodiment, the AP sends a third PPDU to the STA group, where the third PPDU carries a second MPDU, and the second MPDU is configured to trigger the STA that does not successfully receive the data field in the first PPDU to send the third PPDU. The interval between the first time and the third PPDU is a second duration.

In this embodiment, STAs in the STA group that do not correctly receive the data field transmit a second PPDU carrying a non-acknowledgement frame after a second duration (i.e., the first time) after the end time of the third PPDU.

Illustratively, the second time period is predefined, as may be predefined by a protocol. Alternatively, the second duration may be preconfigured by the AP, e.g., the AP may notify STAs in the STA group of the second duration before transmitting the third PPDU, e.g., the AP may notify the STA group through the first PPDU or other PPDUs. Or, the third PPDU further includes information for indicating the second duration, and the STA acquires the second duration from the received third PPDU. The second duration may be included in the XT-SIG, XT-SIG2, or U-SIG of the third PPDU.

The second duration may be referred to as IFS X2 between the third PPDU and the second PPDU, and the IFS of the interval between the end time of the third PPDU and the start time of the second PPDU may be 16 microsecond SIFS, 25 microsecond PIFS, or 34 microsecond DIFS. Alternatively, the second duration may be a value other than the IFS described above, which is not limited in this application.

Optionally, the first frequency band is a transmission frequency band of the third PPDU, or the first PPDU or the third PPDU further includes information for indicating the first frequency band.

For example, as shown in fig. 9, the first frequency band may be a transmission frequency band of the third PPDU. STA1 and STA2 do not correctly receive the data field in the first PPDU, then STA1 and STA2 receive a third PPDU carrying a second MPDU (the second MPDU may be referred to as a non-acknowledgement trigger frame) and transmit the second PPDU carrying the non-acknowledgement frame at a first time spaced from the third PPDU by a second duration X2 and at the same bandwidth as the third PPDU on the transmission frequency band of the third PPDU. Alternatively, the IFS between the third PPDU and the first PPDU may be X3, and the AP may send the third PPDU carrying the unacknowledged trigger frame after a duration X3 after the end time of the first PPDU, where the duration X3 may be 16 microseconds SIFS, 25 microseconds PIFS, or 34 microseconds DIFS.

For another example, the XT-SIG, XT-SIG2, or U-SIG in the first PPDU may include information for indicating the first frequency band, and the STA1 and STA2 determine the first frequency band according to the indication of the first PPDU. STA1 and STA2 receive the third PPDU, transmit a second PPDU carrying a non-acknowledgement frame on the first frequency band at a first time spaced from the third PPDU by a second duration X2.

For another example, the unacknowledged trigger frame carried by the third PPDU includes information for indicating the first frequency band, and STA1 and STA2 send a second PPDU carrying the unacknowledged frame on the first frequency band at a first time spaced from the third PPDU by a second duration X2.

Optionally, in the second embodiment, the physical layer parameter of the second PPDU is indicated by one or more of the following:

the protocol predefines the manner in which the physical layer parameters of the second PPDU are the same as the physical layer processing parameters of the first PPDU or the physical layer parameters of the second PPDU are the same as the physical layer processing parameters of the first PPDU as indicated by the AP,

the physical layer parameter includes one or more parameters of a scrambling code initialization state, a coding mode or a modulation mode, and the physical layer parameter indicated by the AP may specifically be indicated by information in the third PPDU, or may be indicated to the STA group by the AP before sending the third PPDU (such as the first PPDU or other PPDUs).

For example, the scrambling code initialization state of the second PPDU may be the same as the scrambling code initialization state of the third PPDU, and the coding and modulation scheme may be predefined by a binary phase shift keying (binary phase shift keying, BPSK) modulation scheme and a coding scheme with a 1/2 code rate. But the present application is not limited thereto. For example, the physical layer parameters of the second PPDU may be a part of the physical layer parameters identical to those of the first PPDU and a part of the physical layer parameters identical to those of the third PPDU.

In the above two embodiments, the first PPDU may include the above second information for indicating that the STA that needs to incorrectly receive the data field feeds back the unacknowledged frame, and then the STA1 and the STA2 transmit the second PPDU carrying the unacknowledged frame at the first time and in the first frequency band according to the second information in the first PPDU in case that the data field in the first PPDU is incorrectly received. Alternatively, the first PPDU may not include the second information, and in a manner that the STA1 and the STA2 send the second PPDU carrying the unacknowledged frame at the first time and in the first frequency band when the STA1 and the STA2 do not correctly receive the data field in the first PPDU, if the unacknowledged frame is fed back by the STA that does not correctly receive the data field in the multicast PPDU when the multicast data transmission is specified by a protocol or preconfigured by the AP, where the first time is a time spaced from the end time of the first PPDU by the first time length. In another approach, there may be a STA, either specified by the protocol or pre-configured by the AP, that feeds back the non-acknowledgement frame by triggering by the non-acknowledgement trigger frame that the data field of the multicast PPDU was not received correctly. And if the third PPDU is received, the STA1 and the STA2 send a second PPDU carrying the non-acknowledgement frame at a first moment after the third PPDU and in a first frequency band. If the third PPDU is not received, the STA1 and the STA2 do not transmit the second PPDU.

Alternatively, the frame format of the second MPDU (i.e., the unacknowledged trigger frame) may be the same as the frame format of the trigger frame, block Acknowledgement Request (BAR) frame.

For example, the second MPDU may multiplex the frame format of the trigger frame shown in fig. 10, for example, a 4-bit trigger frame type field of bits 0 (B0) to 3 (B3) in the common information field in the trigger frame shown in fig. 10 may indicate one of values 8 to 15, indicating that the trigger frame is specifically a non-acknowledgement trigger frame. As shown in fig. 10a, the 12-bit association identifier field from B0 to B11 in the user information fields other than the special user information field in the user information list field in the trigger frame may indicate a special association identifier corresponding to the multicast address, or may indicate a preset value, for example, the 12 bits each indicate 0, but the application is not limited thereto. Alternatively, the user information list field may not include other user information fields other than the special user information field. The trigger frame as shown in fig. 10 further includes frame control (frame control), duration, RA, TA, padding (padding), and FCS fields. The common information field in the trigger frame may further include an Uplink (UL) length (length), more trigger frames (more trigger frame, more TF) and the like as shown in fig. 10, in addition to the above-mentioned trigger frame type field, and the special user information field in the trigger frame may include an association identifier 12, a physical layer version identifier, an uplink bandwidth extension, an extremely high throughput (extremely high throughput, EHT) spatial multiplexing and the like as shown in fig. 10 a. Other user information of the non-special user information field may include fields such as an association identifier 12, resource Unit (RU) allocation (allocation), uplink forward error correction (forward error correction, FEC) coding type (UL FEC coding type), and the like as shown in fig. 10. The second MPDU may include some or all of these fields as shown in fig. 10. It should be understood that fig. 10 is only one example of a non-acknowledgement trigger frame of the present application, and that one or more fields in the trigger frame that are not related to the non-acknowledgement trigger frame may be indicated as a preset value or as a reserved field.

For another example, the second MPDU may multiplex the frame format of the BAR frame as shown in fig. 11, for example, the MAC frame may be indicated as a non-acknowledgement trigger frame by one of the trigger frame types 11 to 15, for triggering the STA that does not receive the data field in the first PPDU to transmit the non-acknowledgement frame. The block acknowledgement request information in the frame format as a non-acknowledgement trigger frame may indicate a preset value or may not contain block acknowledgement request information.

As another example, the second MPDU may also multiplex an existing multi-user (MU) -BAR trigger frame or multicast with retransmission (groupcast with retries, GCR) MU-BAR trigger frame, i.e., the second MPDU may employ the same trigger frame type as the MU-BAR trigger frame or the GCR MU-BAR trigger frame. Further, the BAR field is included in the MU-BAR trigger frame or the GCR MU-BAR trigger frame, and the MU-BAR trigger frame may be indicated by a BAR Type (Type) in a BAR control (control) field for triggering the first MPDU, for example, the BAR Type indicates 4 or 5 or indicates one of 11 to 15. The trigger frame as shown in fig. 10 may be referred to as a MU-BAR trigger frame or a GCR MU-BAR trigger frame, wherein the BAR control field is located in a common information subfield based on a trigger (frame type) in the MU-BAR trigger frame or the GCR MU-BAR trigger frame.

The above is an example of the second MPDU provided by the present application, and it should be understood that the present application is not limited thereto, and the frame format of the second MPDU may be a frame format dedicated to a non-acknowledgement request frame, and may be different from the frame format of a MAC frame for other purposes. As the type and/or subtype of the second MPDU may be different from the type and/or subtype of the MAC frame for other purposes and the field composition of the second MPDU may be different from the field composition of the MAC frame for other purposes.

For the AP, if receiving the unacknowledged frame sent by the STA in the STA group, the AP determines that the STA group does not successfully receive the multicast data in the first PPDU, and the AP retransmits the PPDU including the multicast data to the STA group, that is, performs retransmission of the multicast data. If the AP does not receive the unacknowledged frame from the STAs in the STA group, the AP considers that the STAs in the STA group correctly receive the multicast data of the first PPDU and do not retransmit. While there may be two cases where the STAs in the STA group do not transmit non-acknowledgement frames, one case is that all STAs in the STA group correctly receive the first PPDU, including correctly receiving the signaling field and the data field. Another case is that one or more STAs in the STA group do not successfully receive the signaling field in the first PPDU, and cannot determine whether the PPDU contains the data field. Since the transmission rate of the signaling field is low and the reliability is high, the probability of transmission error is very low, and thus the AP may consider that all STAs in the STA group correctly receive the first PPDU without receiving a non-acknowledgement frame from the STAs in the STA group.

According to this scheme, STAs in the STA group transmit the non-acknowledgement frame only if the data field is not correctly received, and the STA only feeds back the non-acknowledgement frame can reduce STA power overhead as well as radio resource overhead due to the smaller probability of not receiving the data field relative to the probability of receiving the data field. And a plurality of STAs which do not correctly receive the data field send the non-acknowledgement frame at the same time and the same frequency, compared with a mode that different STAs send the non-acknowledgement frame at different radio resources (such as different time and/or different frequency), the cost of the radio resources can be further reduced, and the radio resource utilization rate is improved. The scheme provided by the application optimizes the retransmission mechanism of the multicast data and improves the efficiency of multicast data transmission.

It should be understood that, in order to implement the functions in the above embodiments, the AP and the STA include corresponding hardware structures and/or software modules that perform the respective functions. Those of skill in the art will readily appreciate that the elements and method steps of the examples described in connection with the embodiments disclosed herein may be implemented as hardware or a combination of hardware and computer software. Whether a function is implemented as hardware or computer software driven hardware depends upon the particular application scenario and design constraints imposed on the solution.

Fig. 12 and 13 are schematic structural diagrams of possible communication devices according to embodiments of the present application. These communication devices may be used to implement the functions of the AP or STA in the above method embodiments, and thus may also implement the beneficial effects of the above method embodiments. In the embodiment of the present application, the communication device may be one of STA1 to STA3 shown in fig. 1, one of AP1 to AP3 shown in fig. 1, or a module (such as a chip) applied to the STA or the AP.

As shown in fig. 12, the communication apparatus 1200 includes a processing unit 1210 and a transceiving unit 1220. The communication device 1200 is configured to implement the functions of the STA or AP in the method embodiment shown in fig. 3.

When the communication apparatus 1200 is used to implement the functions of the STA in the method embodiment shown in fig. 12: the transceiving unit 1220 is for receiving a first PPDU from a first communication device, the first PPDU including a data field including multicast data of a plurality of communication devices. The processing unit 1210 is configured to determine that the data field is not received correctly. The transceiver 1220 is further configured to transmit a second PPDU at a first time and in a first frequency band, where the second PPDU carries a first MPDU, and the first MPDU includes first information, where the first information is used to indicate that the data field is not correctly received, the first time is a time when a second communication device of the plurality of communication devices synchronously transmits the second PPDU, the second communication device is the communication device that does not correctly receive the data field, and the first frequency band is a frequency band in which the second communication device synchronously transmits the second PPDU.

When the communication apparatus 1200 is used to implement the functionality of the AP in the method embodiment shown in fig. 12: the transceiver unit 1220 is configured to transmit a first PPDU, which includes a data field including multicast data of a plurality of communication devices. The transceiver 1220 is further configured to receive a second PPDU at a first time and in a first frequency band, where the second PPDU includes a first MPDU, the first MPDU includes first information, the first information is used to indicate that the data field is not correctly received, the first time is a time when a second communication device of the plurality of communication devices synchronously transmits the first MPDU, the second communication device is the communication device that does not correctly receive the data field, and the first frequency band is a frequency band in which the second communication device synchronously transmits the second PPDU. The processing unit 1210 is configured to determine that the multicast data transmission fails according to the received second PPDU.

For a more detailed description of the processing unit 1210 and the transceiver unit 1220, reference is made to the relevant description of the method embodiment shown in fig. 12.

As shown in fig. 13, communication device 1300 includes a processor 1310 and an interface circuit 1320. Processor 1310 and interface circuit 1320 are coupled to each other. It is understood that the interface circuit 1320 may be a transceiver or an input-output interface. Optionally, the communications device 1300 may also include a memory 1330 for storing instructions executed by the processor 1310 or for storing input data required by the processor 1310 to execute instructions or for storing data generated after the processor 1310 executes instructions.

When the communication apparatus 1300 is used for implementing the method shown in fig. 12, the processor 1310 is used for implementing the functions of the processing unit 1210, and the interface circuit 1320 is used for implementing the functions of the transceiver unit 1220.

When the communication device is a chip applied to the STA, the STA chip realizes the function of the STA in the method embodiment. The STA chip receives information from other modules (such as a radio frequency module or an antenna) in the STA, and the information is sent to the STA by the AP; alternatively, the STA chip sends information to other modules (e.g., radio modules or antennas) in the STA, which the STA sends to the AP.

When the communication device is a module applied to the AP, the AP module implements the functions of the AP in the method embodiment. The AP module receives information from other modules in the AP (e.g., radio frequency modules or antennas), which the STA sends to the AP; alternatively, the AP module sends information to other modules in the AP (e.g., radio frequency modules or antennas) that the AP sends to the STA. The AP module may be a baseband chip of the AP, or may be a DU or other module, where the DU may be a DU under an open radio access network (open radio access network, O-RAN) architecture.

It is to be appreciated that the processor in embodiments of the present application may be a central processing unit (Central Processing Unit, CPU), but may also be other general purpose processors, digital signal processors (Digital Signal Processor, DSP), application specific integrated circuits (Application Specific Integrated Circuit, ASIC), field programmable gate arrays (Field Programmable Gate Array, FPGA) or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. The general purpose processor may be a microprocessor, but in the alternative, it may be any conventional processor.

The method steps in the embodiments of the present application may be implemented in hardware, or in software instructions executable by a processor. The software instructions may be comprised of corresponding software modules that may be stored in random access memory, flash memory, read only memory, programmable read only memory, erasable programmable read only memory, electrically erasable programmable read only memory, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor such the processor can read information from, and write information to, the storage medium. The storage medium may be integral to the processor. The processor and the storage medium may reside in an ASIC. In addition, the ASIC may reside in an AP or STA. The processor and the storage medium may reside as discrete components in an AP or STA.

In the above embodiments, it may be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented in software, may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer programs or instructions. When the computer program or instructions are loaded and executed on a computer, the processes or functions described in the embodiments of the present application are performed in whole or in part. The computer may be a general purpose computer, a special purpose computer, a computer network, a network device, a user device, or other programmable apparatus. The computer program or instructions may be stored in a computer readable storage medium or transmitted from one computer readable storage medium to another computer readable storage medium, for example, the computer program or instructions may be transmitted from one website site, computer, server, or data center to another website site, computer, server, or data center by wired or wireless means. The computer readable storage medium may be any available medium that can be accessed by a computer or a data storage device such as a server, data center, etc. that integrates one or more available media. The usable medium may be a magnetic medium, e.g., floppy disk, hard disk, tape; but also optical media such as digital video discs; but also semiconductor media such as solid state disks. The computer readable storage medium may be volatile or nonvolatile storage medium, or may include both volatile and nonvolatile types of storage medium.

In the various embodiments of the application, if there is no specific description or logical conflict, terms and/or descriptions between the various embodiments are consistent and may reference each other, and features of the various embodiments may be combined to form new embodiments according to their inherent logical relationships.

The foregoing is merely specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily think about changes or substitutions within the technical scope of the present application, and the changes and substitutions are intended to be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A method of communication, comprising:

receiving a first physical layer protocol data unit, PPDU, from a first communication device, the first PPDU comprising a data field, the data field comprising multicast data for a plurality of communication devices;

and transmitting a second PPDU at a first moment and in a first frequency band, wherein the second PPDU carries a first MPDU, the first MPDU comprises first information, the first information is used for indicating that the data field is not correctly received, the first moment is the moment when a second communication device in the plurality of communication devices synchronously transmits the second PPDU, the second communication device is the communication device which does not correctly receive the data field, and the first frequency band is the frequency band when the second communication device synchronously transmits the second PPDU.

2. The method of claim 1, wherein the first PPDU further comprises second information indicating that the second communication device is required to transmit the first MPDU.

3. The method of claim 1 or 2, wherein the first time is spaced from the first PPDU by a first time period, wherein the first time period is predefined, wherein the first time period is preconfigured for the first communication device, or wherein the first PPDU further comprises information indicating the first time period.

4. A method according to any of claims 1 to 3, wherein the first frequency band is a transmission frequency band of the first PPDU or the first PPDU further comprises information indicating the first frequency band.

5. The method according to claim 1 or 2, characterized in that the method further comprises:

receiving a third PPDU from the first communication device, the third PPDU carrying a second MPDU, the second MPDU including third information for triggering the second communication device to synchronously transmit the first MPDU.

6. The method of claim 5, wherein a second time period is spaced between the first time and the third PPDU,

The second duration is predefined or the first duration is preconfigured for the first communication device; or, the first PPDU or the second MPDU further includes information for indicating the first duration.

7. The method according to claim 5 or 6, wherein the first frequency band is a transmission frequency band of the third PPDU; or, the first PPDU or the second MPDU further includes information indicating the first frequency band.

8. The method of any of claims 5-7, wherein a frame format of the second MPDU is the same as a frame format of a trigger frame or a block acknowledgement request frame.

9. The method of claim 8, wherein the trigger frame includes a user information field, wherein the user information field includes an association identifier corresponding to a multicast address of the plurality of communication apparatuses, or wherein the association identifier in the user information field is a predetermined value.

10. The method of any of claims 1-9, wherein a frame format of the first MPDU is the same as a frame format of a quality of service null frame, a frame format of an acknowledgement frame, or a frame format of a block acknowledgement frame.

11. The method of any of claims 1 to 10, wherein the physical layer parameters of the second PPDU are indicated by one or more of:

the physical layer parameters of the second PPDU, or indicated by the first communication device, or the protocol predefined manner are the same as the physical layer processing parameters of the first PPDU;

wherein the physical layer parameters include one or more parameters of a scrambling code initialization state, a coding mode or a modulation mode.

12. A method of communication, comprising:

transmitting a first physical layer protocol data unit, PPDU, the first PPDU comprising a data field, the data field comprising multicast data for a plurality of communication devices;

receiving a second PPDU at a first time and at a first frequency band, the second PPDU including a first MPDU, the first MPDU including first information for indicating that the data field is not correctly received, the first time being a time when a second communication device of the plurality of communication devices synchronously transmits the first MPDU, the second communication device being the communication device that does not correctly receive the data field, the first frequency band being a frequency band in which the second communication device synchronously transmits the second PPDU.

13. The method of claim 12, wherein the first PPDU further comprises second information indicating that the second communication device is required to transmit the first MPDU.

14. The method of claim 12 or 13, wherein a first time period is spaced from the first PPDU by a first time period, wherein the first time period is predefined, wherein the first time period is preconfigured, or wherein the first PPDU further comprises information indicating the first time period.

15. The method of any of claims 12 to 14, wherein the first frequency band is a transmission frequency band of the first PPDU or the first PPDU further comprises information indicating the first frequency band.

16. The method according to claim 12 or 13, characterized in that the method further comprises:

17. The method of claim 16, wherein a second time period is spaced between the first time and the third PPDU,

The second time period is predefined or the first time period is preconfigured; or, the first PPDU or the second MPDU further includes information for indicating the first duration.

18. The method according to claim 16 or 17, wherein the first frequency band is a transmission frequency band of the third PPDU; or, the first PPDU or the second MPDU further includes information indicating the first frequency band.

19. The method of any of claims 16 to 18, wherein a frame format of the second MPDU is the same as a frame format of a trigger frame or a block acknowledgement request frame.

20. The method of claim 19, wherein the trigger frame includes a user information field, wherein the user information field includes an association identifier corresponding to a multicast address of the plurality of communication apparatuses, or wherein the association identifier in the user information field is a predetermined value.

21. The method of any one of claims 12 to 20, wherein a frame format of the first MPDU is the same as a frame format of a quality of service null frame, a frame format of an acknowledgement frame, or a frame format of a block acknowledgement frame.

22. The method of any of claims 12 to 21, wherein the physical layer parameters of the second PPDU are indicated by one or more of:

23. A communication device, comprising:

a unit or module for performing the method of any one of claims 1 to 11; or,

a unit or module for performing the method of any one of claims 12 to 22.

24. A communication device comprising a processor and a memory, the memory and the processor being coupled, the processor being configured to perform the method of any one of claims 1 to 11 or to perform the method of any one of claims 12 to 22.

25. A computer readable storage medium storing instructions which, when executed on a computer, cause the computer to perform the method of any one of claims 1 to 11 or to perform the method of any one of claims 12 to 22.

26. A computer program product comprising instructions which, when run on a computer, cause the computer to perform the method of any one of claims 1 to 11 or to perform the method of any one of claims 12 to 22.