Method, apparatus, storage medium and electronic device for transmitting wireless multi-channel audio

Abstract

The application relates to a wireless multi-channel audio transmission method, device, storage medium and electronic equipment, which comprises the following steps: establishing a connection-isochronous group comprising at least one connection-isochronous flow link supporting an adaptive physical layer, wherein a rate indication field is included in a control packet header of the adaptive physical layer; the transmission time of the connection-isochronous group comprises a series of isochronous intervals, and each isochronous interval of each connection-isochronous flow link comprises a plurality of sub-event intervals; transmitting corresponding protocol data units in at least one sub-event interval of each connection-isochronous flow link in one isochronous interval; at least one connection-isochronous flow link supports an adaptive sub-event maximum length, the adaptive sub-event maximum length is selected from a first sub-event maximum length and a second sub-event maximum length, and the maximum value of the air time required by the protocol data units transmitted on the connection-isochronous flow link is the current sub-event maximum length, so that the quality of audio transmission can be improved.

Description

Technical Field

[0001] This invention relates to the field of wireless communication technology, and in particular to a method, apparatus, storage medium, and electronic device for transmitting Wireless Multi-Channel Audio (WMCA). Background Technology

[0002] Bluetooth Low Energy (BLE) audio technology employs the Isochronous Channels protocol, which includes a Connected Isochronous Stream (CIS) link for point-to-point communication and a Connected Isochronous Group (CIG) consisting of at least one CIS link, as well as a Broadcast Isochronous Stream (BIS) link for point-to-multipoint communication and a Broadcast Isochronous Stream Group (BIG) consisting of at least one BIS link. For example, True Wireless Stereo (TWS) audio is implemented using two CIS links to form a CIG, or Wireless Multi-Channel Audio (WMCA) is implemented using multiple CIS links to form a CIG. Furthermore, with the new generation of BLE specifications supporting the BLE High Data Throughput (HDT) physical layer (PHY), which can provide better performance or higher speeds, such as BLE HDT2PHY at 2Mbps, BLE HDT3 PHY at 3Mbps, BLE HDT4 PHY at 4Mbps, BLE HDT6 PHY at 6Mbps, and BLE HDT7.5 PHY at 7.5Mbps, and even BLE HDTE PHY at up to 15Mbps, BLE Audio can provide better performance or higher bandwidth for True Wireless Lossless Stereo (TWLS) or Wireless Multi-Channel Lossless Audio (WMCLA).

[0003] However, in specific application scenarios, the encoding rate of lossless wireless multichannel audio is constantly changing, as are the required transmission bandwidth, transmission distance, wireless signal fading, and wireless interference. In other words, the wireless communication environment and the corresponding effective bandwidth are constantly changing. Therefore, the existing CIG transmission method, which uses a fixed-rate physical layer (PHY) and fixed link parameters, is difficult to adapt to the constantly changing encoding rate and wireless communication environment. Furthermore, the method of updating the physical layer (PHY) and CIG link parameters through interactive control commands between the CIG central equipment and the CIG peripheral equipment to improve adaptability to the changing wireless communication environment may lead to communication performance instability and is also difficult to adapt to rapidly changing encoding rates and wireless communication environments. Summary of the Invention

[0004] In view of this, the present invention provides a method, apparatus, storage medium and electronic device for transmitting wireless multi-channel audio.

[0005] Specifically, the present invention is achieved through the following technical solution: According to a first aspect of the present invention, a method for transmitting wireless multi-channel audio is provided, the method comprising: A connection isochronous group is established, wherein the connection isochronous group includes at least one connection isochronous stream link, the at least one connection isochronous stream link supports an adaptive physical layer, the adaptive physical layer uses a control packet header that includes a rate indication field, the rate indication field indicating that the current transmission rate of the adaptive physical layer is any one of a predetermined plurality of transmission rates, the transmission time of the connection isochronous group includes a series of isochronous intervals, and each isochronous interval of each connection isochronous stream link includes a plurality of sub-event intervals; Based on each connection isochronous stream link, the corresponding protocol data unit is transmitted within at least one sub-event interval of an isochronous interval. At least one connection isochronous stream link supports adaptive sub-event maximum length. The adaptive sub-event maximum length refers to the selection of the first event maximum length and the second event maximum length based on the current encoding rate of the audio data and the current transmission rate of the adaptive physical layer. The second event maximum length is greater than the first event maximum length. The maximum air time required for the protocol data unit transmitted on at least one connection isochronous stream link that supports adaptive sub-event maximum length is the current sub-event maximum length. The protocol data unit carries one or more frames of audio encoded data obtained by encoding audio data of a predetermined duration based on the current encoding rate.

[0006] Optionally, the connection isochronous group includes a first connection isochronous flow link and a second connection isochronous flow link. The first connection isochronous stream link and / or the second connection isochronous stream link support adaptive physical layer and adaptive maximum sub-event length.

[0007] Optionally, The current encoding rate varies depending on the predetermined duration of audio data, the size of each frame of encoded audio data varies, and the size of the protocol data unit varies. When the current encoding rate of the audio data and the current transmission rate of the adaptive physical layer are used, if the airtime required to transmit the protocol data unit is greater than the maximum length of the first event, then the maximum length of the second event is selected as the current maximum length of the next event; if the airtime required to transmit the protocol data unit is less than or equal to the maximum length of the first event, then the maximum length of the first event is selected as the current maximum length of the next event. When the maximum length of the first event is used as the maximum length of the current second event, there are no second events with shared time. When the maximum length of the second event is used as the maximum length of the current sub-event, there are sub-events with shared time.

[0008] Optionally, Multiple isochronous stream links coexist in time-division multiplexing mode in an interleaved mode. When one or two of the first and second isochronous stream links use the maximum length of the second event as the maximum length of the current sub-event, the sub-event of the protocol data unit transmitted based on the first isochronous stream link and the sub-event of the protocol data unit transmitted based on the second isochronous stream link do not overlap in the time domain. At this time, there are sub-events with shared time between the first and second isochronous stream links. When both the first and second isochronous stream links use the maximum length of the first event as the maximum length of the current secondary event, the secondary event of the protocol data unit transmitted based on the first isochronous stream link does not overlap with the secondary event of the protocol data unit transmitted based on the second isochronous stream link in the time domain. In this case, there are no secondary events with shared time between the first and second isochronous stream links. The maximum length of the second event is no greater than the interval between the second events.

[0009] Optionally, When the first connection isochronous stream link or the second connection isochronous stream link takes the maximum length of the second event as the maximum length of the current sub-event, and the sub-event based on the protocol data unit transmitted by the first connection isochronous stream link overlaps with the sub-event based on the protocol data unit transmitted by the second connection isochronous stream link in the time domain, the sub-event executed later in the second connection isochronous stream link and the first connection isochronous stream link is left empty to avoid the sub-event executed earlier.

[0010] Optionally, based on the channel quality of the isochronous stream links, a predetermined plurality of transmission rates may be adaptively selected as the current highest transmission rate of the adaptive physical layer. The channel quality of the isochronous stream link of the connection is determined based on the packet loss rate of the transmitted protocol data units.

[0011] Optionally, Within each equal time interval, the starting point of each secondary event for each connected equal time stream link is the same, and the protocol data unit is transmitted starting from the starting point of the corresponding secondary event; Within each isochronous interval, the sub-event intervals for each connected isochronous stream link are the same.

[0012] Optionally, The maximum length of the current event can be changed within a single time interval and / or between different time intervals. The adaptive physical layer supports changing its current transmission rate within an isochronous interval and / or between different isochronous intervals.

[0013] Optionally, When establishing each connection isochronous flow link, a link-layer connection isochronous flow request protocol data unit is sent to surrounding devices. The control data of the link-layer connection isochronous flow request protocol data unit includes: a reconfigurable connection isochronous group enable flag. The reconfigurable connection isochronous group enable flag is valid, indicating that the connection isochronous flow link supports adaptive physical layer and adaptive sub-event maximum length; The reconfigurable connection isochronous group enable flag is invalid, indicating that the connection isochronous flow link does not support adaptive physical layer and adaptive sub-event maximum length.

[0014] Optionally, if the current channel quality of the isochronous stream link is lower than a first predetermined quality threshold, it is considered that the current channel quality of the isochronous stream link is too low to be suitable for transmission at the current transmission rate of the adaptive physical layer, and the current transmission rate of the adaptive physical layer of the isochronous stream link is changed to a lower transmission rate until the current transmission rate of the adaptive physical layer is the lowest transmission rate. If the current channel quality of the isochronous stream link is higher than the second predetermined quality threshold, it is considered that the current channel quality of the isochronous stream link is too high and is not suitable for the current transmission rate of the adaptive physical layer. The current transmission rate of the adaptive physical layer of the isochronous stream link is then changed to a higher transmission rate until the current transmission rate of the adaptive physical layer is the highest transmission rate.

[0015] The wireless multi-channel audio transmission method in this technical solution establishes a connection isochronous group, wherein the connection isochronous group includes at least one connection isochronous stream link, and the at least one connection isochronous stream link supports an adaptive physical layer. The control packet header used by the adaptive physical layer includes a rate indication field, which indicates that the current transmission rate of the adaptive physical layer is any one of a predetermined plurality of transmission rates. The transmission time of the connection isochronous group includes a series of isochronous intervals, and each isochronous stream link includes multiple sub-event intervals within each isochronous interval. Based on each connection isochronous stream link, the corresponding protocol data unit is transmitted within at least one sub-event interval of an isochronous interval, wherein... At least one isochronous streaming link supports an adaptive sub-event maximum length. This adaptive sub-event maximum length refers to the current sub-event maximum length, which is adaptively selected from a first event maximum length and a second event maximum length based on the current encoding rate of the audio data and the current transmission rate of the adaptive physical layer. The second event maximum length is greater than the first event maximum length. The maximum airtime required for the transmission of protocol data units on at least one isochronous streaming link supporting the adaptive sub-event maximum length is the current sub-event maximum length. The protocol data unit carries one or more frames of encoded audio data obtained by encoding audio data of a predetermined duration based on the current encoding rate. Thus, by dynamically employing an adaptive physical layer and transmitting corresponding protocol data units within sub-event intervals based on adaptive shared time, without switching audio encoding rates, the adaptability to rapidly changing wireless communication environments in wireless multi-channel audio transmission can be effectively improved, while ensuring the quality of transmitted audio.

[0016] According to a second aspect of the present invention, a wireless multi-channel audio transmission device is provided, the wireless multi-channel audio transmission device comprising: A connection isochronous group construction module is used to establish a connection isochronous group, wherein the connection isochronous group includes at least one connection isochronous flow link, the at least one connection isochronous flow link supports an adaptive physical layer, the control packet header used by the adaptive physical layer includes a rate indication field, the rate indication field indicates that the current transmission rate of the adaptive physical layer is any one of a predetermined plurality of transmission rates, the transmission time of the connection isochronous group includes a series of isochronous intervals, and each isochronous interval of each connection isochronous flow link includes a plurality of sub-event intervals; The protocol data unit transmission module is used to transmit corresponding protocol data units within at least one sub-event interval of an isochronous stream link based on each connection, wherein at least one connection isochronous stream link supports adaptive sub-event maximum length. The adaptive sub-event maximum length refers to the selection of a first event maximum length and a second event maximum length based on the current encoding rate of the audio data and the current transmission rate of the adaptive physical layer. The second event maximum length is greater than the first event maximum length. The maximum air time required for the protocol data unit transmitted on at least one connection isochronous stream link that supports the adaptive sub-event maximum length is the maximum length of the current sub-event. The protocol data unit carries one or more frames of audio encoded data obtained by encoding audio data of a predetermined duration based on the current encoding rate.

[0017] Optionally, the current encoding rate varies with the amount of audio data of a predetermined duration, the size of each frame of encoded audio data varies, and the size of the protocol data unit varies. The protocol data unit transmission module is also used for: When the current encoding rate of the audio data and the current transmission rate of the adaptive physical layer are used, if the airtime required to transmit the protocol data unit is greater than the maximum length of the first event, then the maximum length of the second event is selected as the current maximum length of the next event; if the airtime required to transmit the protocol data unit is less than or equal to the maximum length of the first event, then the maximum length of the first event is selected as the current maximum length of the next event. When the maximum length of the first event is used as the maximum length of the current secondary event, there are no secondary events with shared time between the isochronous flow links of each connection. When the maximum length of the second event is used as the maximum length of the current sub-event, then the sub-events with shared time are available between the isochronous flow links of each connection.

[0018] According to a third aspect of the present invention, a method for transmitting wireless multi-channel audio is provided, applied to a receiving device, comprising: A connection isochronous stream link is established with the transmitting device, wherein the transmitting device also establishes one or more connection isochronous stream links with other receiving devices, the multiple connection isochronous stream links form a connection isochronous group, at least one connection isochronous stream link supports an adaptive physical layer, the control packet header used by the adaptive physical layer includes a rate indication field, the rate indication field indicates that the current transmission rate of the adaptive physical layer is any one of a predetermined plurality of transmission rates, the transmission time of the connection isochronous group includes a series of isochronous intervals, and each isochronous interval of each connection isochronous stream link includes a plurality of sub-event intervals; Within the current isochronous interval, when receiving protocol data units at the sub-event interval of the corresponding isochronous stream link, the current transmission rate of the adaptive physical layer is adaptively identified based on the rate indication field in the control packet header used by the physical layer, thereby adaptively switching the adaptive physical layer to the corresponding transmission rate.

[0019] Optionally, Within each equal time interval, the secondary event start point is the same for each connected equal time stream link; Within each isochronous interval, the sub-event intervals for each connected isochronous stream link are the same.

[0020] According to a fourth aspect of the present invention, a storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the steps of the wireless multi-channel audio transmission method in any possible implementation of the first aspect.

[0021] According to a fifth aspect of the present invention, an electronic device is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the steps of the wireless multi-channel audio transmission method in any possible implementation of the first aspect. Attached Figure Description

[0022] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, those skilled in the art can obtain other drawings based on these drawings without creative effort.

[0024] Figure 1 A flowchart illustrating a wireless multi-channel audio transmission method provided in an embodiment of the present invention; Figure 2This is a schematic diagram of a wireless multi-channel audio adaptive transmission system provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the first time slot structure of the RCIG according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the second time-slot structure of the RCIG according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the third time-slot structure of the RCIG according to an embodiment of the present invention; Figure 6 This is another schematic flowchart illustrating a wireless multi-channel audio transmission method provided in an embodiment of the present invention. Figure 7 A schematic diagram of a wireless multi-channel audio transmission device provided in an embodiment of the present invention; Figure 8 This is a schematic diagram of another wireless audio transmission device provided in an embodiment of the present invention; Figure 9 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] This embodiment provides an adaptive transmission method for wireless multi-channel lossless audio (hereinafter referred to as wireless multi-channel audio or audio). It employs at least two Reconfigurable Connected Isochronous Stream (RCIS) links to transmit wireless multi-channel lossless audio data, with the at least two RCIS links forming a Reconfigurable Connected Isochronous Group (RCIG). Specifically, the at least two RCIS links utilize adaptive physical layer (PHY) and adaptive shared time (AST) sub-events (i.e., adaptive maximum sub-event length) to support variable coding rate wireless multi-channel lossless audio transmission. By employing RCIG to adapt to rapid changes in the wireless multi-channel lossless audio coding rate and the wireless environment, while maintaining consistent wireless multi-channel lossless audio quality, the method effectively solves the balance problem between variable coding rate and effective bandwidth in WMCLA transmission.

[0027] It should be noted that RCIS can also be referred to as Connected Isochronous Stream Link (CIS) in this invention, and RCIG can also be referred to as Connected Isochronous Group (CIG). However, the Connected Isochronous Stream Link CIS and Connected Isochronous Group CIG in this invention have made some improvements compared to existing CIS and CIG. For example, the RCIS link can support the adaptive physical layer and adaptive shared time sub-events defined in this invention, while existing CIS links do not support the adaptive physical layer and adaptive shared time sub-events defined in this invention. RCIG includes at least one RCIS link, while existing CIGs do not include an RCIS link. Thus, RCIG can support wireless multi-channel lossless audio transmission with variable coding rates.

[0028] See Figure 1 This invention provides a method for transmitting wireless multi-channel audio, applied to a transmitting device, which may include the following steps: S101. Establish a connection isochronous group, wherein the connection isochronous group includes at least one connection isochronous stream link, the at least one connection isochronous stream link supports an adaptive physical layer, the control packet header used by the adaptive physical layer includes a rate indication field, the rate indication field indicates that the current transmission rate of the adaptive physical layer is any one of a predetermined plurality of transmission rates, the transmission time of the connection isochronous group includes a series of isochronous intervals, and each isochronous interval of each connection isochronous stream link includes a plurality of sub-event intervals; In one embodiment, taking an isochronous stream link as an example, it can be understood that isochronous stream link transmission, as a common data transmission method, is widely used in audio stream transmission with high real-time requirements due to its emphasis on time accuracy and periodicity, and its ability to ensure timing stability through coordinated bandwidth allocation. In some embodiments, each wireless link can be an isochronous stream link, and multiple wireless links form a single isochronous stream link group. The isochronous stream link group defines common timing parameters for all isochronous stream links within the group.

[0029] In one embodiment, the connection isochronous group employs a connection-oriented isochronous stream data transmission mechanism.

[0030] In some specific embodiments of this application, the connecting isochronous stream link can be a CIS link established with reference to the BLE CIS link protocol, or it can be a CIS link established based on other public or private connection-oriented isochronous stream transmission mechanisms. The connecting isochronous stream link in this invention is not exactly the same as the existing BLE CIS link, but rather has been improved or modified to some extent; however, the basic principle of the isochronous stream transmission mechanism is the same for both. The improvements or modifications made to the existing BLE CIS link will be described in detail in this invention, while the parts that are the same will not be repeated.

[0031] Figure 2 This is a schematic diagram of a wireless multi-channel audio adaptive transmission system provided in an embodiment of the present invention. Figure 2 As shown, the wireless multi-channel audio adaptive transmission system includes a WMCLA transmitting device and a WMCLA terminal device. In one embodiment, the WMCLA terminal device is a receiving device, i.e., a wireless audio receiving device. Taking two different units of the same wireless audio receiving device as an example, where the first receiving device (WMCLA receiving device 1) and the second receiving device (WMCLA receiving device 2) are both examples, the transmitting device is the WMCLA transmitting device. The WMCLA transmitting device includes, but is not limited to, audio source devices. The WMCLA terminal device consists of at least two (N>1) wireless mono lossless audio (WMLA) receiving devices. The WMCLA transmitting device and the WMCLA terminal device transmit multi-channel wireless lossless audio via a reconfigurable connection isochronous stream link as described in this embodiment. At least two RCIS links constitute a reconfigurable connection isochronous group. The WMCLA transmitting device is the central device of the reconfigurable connection isochronous group, and the WMCLA terminal device is a peripheral device of the reconfigurable connection isochronous group.

[0032] In some specific embodiments of this application, the first receiving device and the second receiving device can be different wireless audio receiving devices. In other specific embodiments of this application, the first receiving device and the second receiving device can also be two different units of the same wireless audio receiving device. For example, TWS earphones serve as a wireless audio receiving device, with the left and right channel earphones corresponding to the first and second receiving devices, respectively. As another example, the wireless audio receiving device can also be a stereo headset with left and right channels. Alternatively, it can be a stereo speaker with left and right channels, or a multi-channel speaker with multiple channels.

[0033] In this embodiment, the RCIS Protocol Data Unit (PDU) of the RCIS link is defined the same as the CISPDU.

[0034] In this embodiment, to support RCIG, one bit in the reserved field (RFU, Reserved for Future Use) of the original control data (CtrData) of the BLE specification's link layer connection isochronous flow request (LL_CIS_REQ) PDU is defined as the RCIG enable flag (RCIG_En). If RCIG_En is set to 1, it indicates that the CIG central device supports RCIG; if it is set to 0, it indicates that the CIG central device does not support RCIG. Therefore, as an optional embodiment, when establishing each connection isochronous flow link, a link layer connection isochronous flow request protocol data unit is sent to peripheral devices. The control data of the link layer connection isochronous flow request protocol data unit includes: a reconfigurable connection isochronous group enable flag. The reconfigurable connection isochronous group enable flag is valid, indicating that the connection isochronous flow link supports adaptive physical layer and adaptive sub-event maximum length; The reconfigurable connection isochronous group enable flag is invalid, indicating that the connection isochronous flow link does not support adaptive physical layer and adaptive sub-event maximum length.

[0035] In one embodiment, taking at least two RCIS links including a first reconfigurable connection isochronous stream link (also referred to as the first connection isochronous stream link) and a second reconfigurable connection isochronous stream link (also referred to as the second connection isochronous stream link) as an example, the WMCA transmitting device employs an adaptive physical layer that supports multiple transmission rates of different speeds, such as BLE HDT3, BLE HDT4, and BLE HDT6. The WMCA transmitting device determines whether the transmission rate of the adaptive physical layer needs to be readjusted based on the channel quality of the reconfigurable connection isochronous stream link. If it is determined that the transmission rate of the adaptive physical layer needs to be reselected, the transmission rate of the adaptive physical layer of the first reconfigurable connection isochronous stream link and / or the second reconfigurable connection isochronous stream link is changed accordingly. For example, if the current channel quality of the first reconfigurable connection isochronous stream link and / or the second reconfigurable connection isochronous stream link is too low to be suitable for transmission at the current transmission rate of the adaptive physical layer, then the transmission rate of the adaptive physical layer of the first reconfigurable connection isochronous stream link and / or the second reconfigurable connection isochronous stream link will be changed to a lower transmission rate until the transmission rate of the adaptive physical layer is at its lowest; if the current channel quality of the first reconfigurable connection isochronous stream link and / or the second reconfigurable connection isochronous stream link is too high to be suitable for transmission at the current transmission rate of the adaptive physical layer, then the transmission rate of the adaptive physical layer of the first reconfigurable connection isochronous stream link and / or the second reconfigurable connection isochronous stream link will be changed to a higher transmission rate until the transmission rate of the current physical layer is at its highest.

[0036] In this embodiment, the RCIG central device determines the transmission rate of the adaptive physical layer used for lossless audio data transmission based on the wireless channel quality: For high channel quality, i.e., in short-range wireless communication environments with low fading and interference, the RCIS link uses a high transmission rate adaptive physical layer to transmit lossless audio data. For low channel quality, i.e., in long-range wireless communication environments with high fading and interference, the RCIS link uses a low transmission rate adaptive physical layer to transmit lossless audio data. For medium channel quality, i.e., in medium-range wireless communication environments with medium fading and interference, the RCIS link can also use a medium transmission rate adaptive physical layer to transmit lossless audio data. In one example, the RCIG central device judges the wireless channel quality based on the packet loss rate statistically analyzed from the reception acknowledgment information fed back by the RCIG peripheral devices.

[0037] In one embodiment, an adaptive physical layer adaptively selects one of a predetermined plurality of transmission rates as its current highest transmission rate based on the current channel quality. After selecting the current transmission rate of the adaptive physical layer, the adaptive physical layer can transmit protocol data units at a transmission rate no higher than the current highest transmission rate. In one example, the channel quality of the isochronous stream link of the connection is determined based on the packet loss rate of the transmitted protocol data units. For example, if the current channel quality is too low relative to the current transmission rate of the adaptive physical layer, a transmission rate lower than the current transmission rate of the adaptive physical layer needs to be selected for transmission to avoid channel quality deterioration; conversely, if the current channel quality is too high relative to the current transmission rate of the adaptive physical layer, a transmission rate higher than the current transmission rate of the adaptive physical layer needs to be selected for transmission to effectively utilize bandwidth resources and improve data transmission efficiency.

[0038] In another example, when the current channel quality of the isochronous stream link is lower than a first predetermined quality threshold, it is considered that the current channel quality of the isochronous stream link is too low to be suitable for transmission at the current transmission rate of the adaptive physical layer. The current transmission rate of the adaptive physical layer of the isochronous stream link is then changed to a lower transmission rate until the current transmission rate of the adaptive physical layer is the lowest possible transmission rate. If the current channel quality of the isochronous stream link is higher than the second predetermined quality threshold, it is considered that the current channel quality of the isochronous stream link is too high and is not suitable for the current transmission rate of the adaptive physical layer. The current transmission rate of the adaptive physical layer of the isochronous stream link is then changed to a higher transmission rate until the current transmission rate of the adaptive physical layer is the highest transmission rate.

[0039] In one embodiment, as another optional embodiment, a lower transmission rate than the current transmission rate is selected when the load on the service data unit and RCIS PDU decreases, and a higher transmission rate than the current transmission rate is selected when the load on the service data unit and RCIS PDU increases.

[0040] In one embodiment, as an optional embodiment, a quality threshold is set to evaluate channel quality. For example, if the current channel quality of the first reconfigurable connection isochronous stream link and / or the second reconfigurable connection isochronous stream link is lower than a first predetermined quality threshold THQA, then it is considered that the current channel quality of the first reconfigurable connection isochronous stream link and / or the second reconfigurable connection isochronous stream link is too low to be suitable for selecting the current transmission rate of the adaptive physical layer for transmission. The current transmission rate of the adaptive physical layer of the first reconfigurable connection isochronous stream link and / or the second reconfigurable connection isochronous stream link is changed to a lower transmission rate until the current transmission rate of the adaptive physical layer is the lowest transmission rate. If the current channel quality of the first reconfigurable connection isochronous stream link and / or the second reconfigurable connection isochronous stream link is higher than the second quality threshold THQB, then it is considered that the current channel quality of the first reconfigurable connection isochronous stream link and / or the second reconfigurable connection isochronous stream link is too high to be suitable for transmission at the current transmission rate of the adaptive physical layer. The current transmission rate of the adaptive physical layer of the first reconfigurable connection isochronous stream link and / or the second reconfigurable connection isochronous stream link is changed to a higher transmission rate until the current transmission rate of the adaptive physical layer is the highest transmission rate.

[0041] In one embodiment, taking the first reconfigurable connection isochronous stream link as an example, if the current channel quality of the first reconfigurable connection isochronous stream link is lower than the first quality threshold THQA, it indicates that if data transmission is performed at the current transmission rate of the adaptive physical layer, the quality of data transmission may become increasingly worse, causing channel quality deterioration. Therefore, it is not suitable to select the current transmission rate of the adaptive physical layer for transmission, and the current transmission rate of the adaptive physical layer of the first reconfigurable connection isochronous stream link needs to be changed to a lower transmission rate. If the current channel quality of the first reconfigurable connection isochronous stream link is still lower than the first quality threshold THQA after changing to a lower transmission rate for data transmission, then the transmission rate is changed to an even lower rate until the current transmission rate of the adaptive physical layer is the lowest transmission rate. For the second reconfigurable connection isochronous stream link, an adaptive transmission rate is selected from a predetermined plurality of transmission rates as the current transmission rate of the adaptive physical layer, similar to the selection for the first reconfigurable connection isochronous stream link: if the current channel quality of the second reconfigurable connection isochronous stream link is lower than the first quality threshold THQA, it indicates that if data transmission is performed at the current transmission rate of the adaptive physical layer, the quality of data transmission may deteriorate, causing channel quality degradation. Therefore, it is not suitable to select the current transmission rate for transmission, and the current transmission rate of the adaptive physical layer of the second reconfigurable connection isochronous stream link needs to be changed to a lower transmission rate. If the current channel quality of the second reconfigurable connection isochronous stream link is still lower than the first quality threshold THQA after changing to a lower transmission rate for data transmission, then the transmission rate is changed to an even lower rate until the current transmission rate of the adaptive physical layer is the lowest transmission rate. Similarly, if the current channel quality of the first reconfigurable isochronous stream link is higher than the second quality threshold THQB, it indicates that if data transmission is performed at the current transmission rate of the adaptive physical layer, the bandwidth utilization is relatively low, and the transmission rate is too low. Therefore, it is not suitable to select the current transmission rate of the adaptive physical layer for transmission, and the current transmission rate of the adaptive physical layer of the first reconfigurable isochronous stream link needs to be changed to a higher transmission rate. If, after changing to a higher transmission rate for data transmission, the current channel quality of the first reconfigurable isochronous stream link is still higher than the second quality threshold THQB, then it is changed to a higher transmission rate again, until the current transmission rate of the adaptive physical layer is at its maximum. The same principle applies to the second reconfigurable isochronous stream link, so it will not be repeated here. In this embodiment, the quality threshold THQA is different from the quality threshold THQB. The quality threshold THQA can be called the low quality threshold THQA, and the quality threshold THQB can be called the high quality threshold THQB.

[0042] In one embodiment, the current packet loss rate characterizes the current channel quality; therefore, as an optional embodiment, The current packet loss rate of the protocol data unit is used as the current channel quality. If the current packet loss rate of the protocol data unit is higher than a packet loss rate threshold THA, then the current channel quality is considered to be lower than a first quality threshold THQA. When the current packet loss rate of the protocol data unit is lower than another packet loss rate threshold THB, the current channel quality is considered to be higher than a second quality threshold THQB, where the packet loss rate threshold THA is higher than the packet loss rate threshold THB. The packet loss rate threshold THA can be called the high packet loss rate threshold THA, and the packet loss rate threshold THB can be called the low packet loss rate threshold THB. In this embodiment, as an optional implementation, when the packet loss rate of the RCIS PDU transmitted at a high transmission rate by the adaptive physical layer is higher than a preset first threshold (e.g., 10%), the high transmission rate of the adaptive physical layer is switched to a medium transmission rate for the RCIS PDU. When the packet loss rate of the RCIS PDU transmitted at a medium transmission rate is higher than a preset second threshold (e.g., 10%), the medium transmission rate of the adaptive physical layer is switched to a low transmission rate for the RCIS PDU. As another optional implementation, when the packet loss rate of the RCIS PDU transmitted at a low transmission rate by the adaptive physical layer is lower than a preset third threshold (e.g., 1%), the low transmission rate of the adaptive physical layer is switched to a medium transmission rate for the RCIS PDU. When the packet loss rate of the RCIS PDU transmitted at a medium rate by the adaptive physical layer is lower than a preset fourth threshold (e.g., 1%), the medium transmission rate of the adaptive physical layer is switched to a high transmission rate for the RCIS PDU. Among them, the first threshold is higher than the third threshold, the second threshold is higher than the fourth threshold, the first threshold is not higher than the second threshold, and the fourth threshold is not higher than the third threshold.

[0043] In one embodiment, as an optional embodiment, the adaptive physical layer supports multiple transmission rates, including at least a high transmission rate and a low transmission rate. For example, the high transmission rate could be 6 Mbps, and the low transmission rate could be 3 Mbps. The adaptive physical layers with different rates use the same training sequence and control header. The control header includes a rate indicator field (RI), which indicates that the current transmission rate of the adaptive physical layer is any one of a predetermined plurality of transmission rates. Thus, when the first receiving device and the second receiving device receive protocol data units, they determine the current transmission rate of the adaptive physical layer of the first reconfigurable connection isochronous stream link and the second reconfigurable connection isochronous stream link by using the rate indicator field in the physical layer's control header, and switch to the physical layer with the corresponding transmission rate for reception.

[0044] In this embodiment, an RCIG is established between the WMCLA transmitting device and the WMCLA terminal device. After setting RCIG_En to 1 in CtrData of LL_CIS_REQPDU, an adaptive physical layer (PHY) type definition is added to the physical layer parameter PHY_C_To_P or PHY_P_To_C in LL_CIS_REQ PDU. That is, in addition to the fixed-rate PHY types such as LE 1M PHY, LE 2MPHY, and LE Coded PHY in related technologies, an adaptive physical layer (Adaptive PHY) type is also defined. The Adaptive PHY uses the same training sequence and control header as the BLE High Data Throughput (HDT) physical layer. In one embodiment, the transmission rate of the adaptive physical layer is identified by a rate indication field in the control header. This allows the RCIG central device to adaptively select different transmission rates of the adaptive physical layer to transmit lossless audio data with variable coding rates according to the rapidly changing wireless communication environment.

[0045] In another embodiment, the adaptive physical layer supports at least a high transmission rate, a medium transmission rate, and a low transmission rate. In this invention, many parts are described using high and low transmission rates as examples, but this should not be construed as limiting it to only two transmission rates.

[0046] S102. Based on each connection isochronous stream link, the corresponding protocol data unit is transmitted within at least one sub-event interval of an isochronous interval, wherein at least one connection isochronous stream link supports adaptive sub-event maximum length. The adaptive sub-event maximum length refers to the selection of the first event maximum length and the second event maximum length adaptively based on the current encoding rate of the audio data and the current transmission rate of the adaptive physical layer. The second event maximum length is greater than the first event maximum length. The maximum air time required for the protocol data unit transmitted on at least one connection isochronous stream link that supports adaptive sub-event maximum length is the current sub-event maximum length. The protocol data unit carries one or more frames of audio encoded data obtained by encoding audio data of a predetermined duration based on the current encoding rate.

[0047] In this embodiment, after establishing RCIG between the WMCLA transmitting device and the WMCLA terminal device, the RCIG central device can use adaptively shared airtime (RCIS) sub-events for data transmission. Here, an adaptively shared airtime sub-event means that multiple RCIS links can share airtime, meaning the maximum length of the current sub-event of an RCIS link varies, indicating that the RCIS link supports an adaptive maximum sub-event length. Sub-events of at least two RCIS links can overlap in time. Therefore, as an optional embodiment, the connection isochronous group includes a first connection isochronous stream link and a second connection isochronous stream link. The first connection isochronous stream link can also be referred to as a first reconfigurable connection isochronous stream link, and the second connection isochronous stream link can also be referred to as a second reconfigurable connection isochronous stream link. The first connection isochronous stream link and / or the second connection isochronous stream link support adaptive physical layer and adaptive maximum sub-event length.

[0048] In this embodiment, as an optional embodiment, the starting point of each secondary event of each connected isochronous stream link is the same within each isochronous interval, and the protocol data unit is transmitted starting from the starting point of the corresponding secondary event. Within each isochronous interval, the sub-event interval for each connected isochronous stream link is the same. With this setup, even if the required airtime for the protocol data unit varies, the receiving device can receive the protocol data unit at a predetermined sub-event start point without requiring further negotiation between the two parties.

[0049] In this embodiment, as an optional implementation, the current encoding rate varies with the audio data of a predetermined duration, the size of each frame of encoded audio data varies, and the size of the protocol data unit varies. When the current encoding rate of the audio data and the current transmission rate of the adaptive physical layer are used, if the airtime required to transmit the protocol data unit is greater than the maximum length of the first event, then the maximum length of the second event is selected as the current maximum length of the next event; if the airtime required to transmit the protocol data unit is less than or equal to the maximum length of the first event, then the maximum length of the first event is selected as the current maximum length of the next event. When the maximum length of the first event is used as the maximum length of the current secondary event, there are no secondary events with shared time between the first connection isochronous stream link and the second connection isochronous stream link. When the maximum length of the second event is used as the maximum length of the current sub-event, there are sub-events with shared time between the first connection isochronous stream link and the second connection isochronous stream link.

[0050] In this embodiment, after establishing RCIG between the WMCLA transmitting device and the WMCLA terminal device, the RCIG central device adaptively selects different transmission rates of the adaptive physical layer and the adaptive maximum length of the sub-event to transmit multi-channel lossless audio data based on the rapidly changing coding rate and the rapidly changing wireless communication environment. The adaptive maximum length of the sub-event refers to the selection of a maximum length from the first and second events based on the current coding rate of the audio data and the current transmission rate of the adaptive physical layer. The second maximum length of the sub-event is greater than the first maximum length of the sub-event. The second maximum length of the sub-event is not greater than the sub-event interval. The changing coding rate corresponds to varying sizes of Service Data Units (SDUs) and varying lengths of RCIS PDU payloads; a higher coding rate corresponds to a larger SDU and RCIS PDU payload, and a lower coding rate corresponds to a smaller SDU and RCIS PDU payload. Between or within each isochronous interval, the starting point of the first reconfigurable connection isochronous stream link and the starting point of the second reconfigurable connection isochronous stream link are the same whether or not the secondary event time is shared; the secondary event interval of the first reconfigurable connection isochronous stream link and the secondary event interval of the second reconfigurable connection isochronous stream link are the same whether or not the secondary event time is shared; the maximum secondary event length of the first reconfigurable connection isochronous stream link and the maximum secondary event length of the second reconfigurable connection isochronous stream link are different whether or not the secondary event time is shared; when the secondary event time is shared, the maximum secondary event length is greater than the maximum secondary event length when the secondary event time is not shared.

[0051] In this embodiment, as an optional embodiment, multiple connection isochronous stream links coexist in an interleaved mode using time-division multiplexing. When one or two of the first connection isochronous stream links and the second connection isochronous stream links use the maximum length of the second event as the maximum length of the current sub-event, the sub-event of the protocol data unit transmitted based on the first connection isochronous stream link and the sub-event of the protocol data unit transmitted based on the second connection isochronous stream link overlap in the time domain. At this time, there are sub-events with shared time between the first connection isochronous stream link and the second connection isochronous stream link. When both the first connection isochronous stream link and the second connection isochronous stream link take the maximum length of the first event as the maximum length of the current secondary event, the secondary event of the protocol data unit transmitted based on the first connection isochronous stream link and the secondary event of the protocol data unit transmitted based on the second connection isochronous stream link do not overlap in the time domain. At this time, there are no secondary events with shared time between the first connection isochronous stream link and the second connection isochronous stream link.

[0052] In this embodiment, as an optional embodiment, when the first connection isochronous stream link or the second connection isochronous stream link takes the maximum length of the second event as the maximum length of the current sub-event, and the sub-event based on the protocol data unit transmitted by the first connection isochronous stream link overlaps with the sub-event based on the protocol data unit transmitted by the second connection isochronous stream link in the time domain, the sub-event executed later in the second connection isochronous stream link and the first connection isochronous stream link is left empty to avoid the sub-event executed earlier.

[0053] In this embodiment, as an optional implementation, it is possible to change the maximum length of the current event within one equal time interval and / or between different equal time intervals. The adaptive physical layer supports changing its current transmission rate within an isochronous interval and / or between different isochronous intervals.

[0054] In one embodiment, when a low coding rate is used and the adaptive physical layer uses a medium-high transmission rate for protocol data unit transmission, the first reconfigurable connection isochronous stream link and the second reconfigurable connection isochronous stream link use the maximum length of the first event as the maximum length of the current sub-event. At this time, there are no sub-events with shared time between the first reconfigurable connection isochronous stream link and the second reconfigurable connection isochronous stream link. When a protocol data unit is transmitted using a high coding rate and a medium-low rate, resulting in the reconfigurable connection isochronous stream link protocol data unit air time being greater than the maximum length of the first event, the first reconfigurable connection isochronous stream link and the second reconfigurable connection isochronous stream link adopt the maximum length of the second event as the maximum length of the current sub-event. At this time, the first reconfigurable connection isochronous stream link and the second reconfigurable connection isochronous stream link have sub-events with shared time, wherein the maximum length of the second event is greater than the maximum length of the first event. More specifically, in the case of low coding rate, if the protocol data unit payload length does not exceed the first length threshold, if the channel quality is good, the maximum length of the first event is selected to be combined with the high transmission rate of the adaptive physical layer; if the channel quality is medium, the maximum length of the first event is selected to be combined with the medium transmission rate of the adaptive physical layer; if the channel quality is poor, the maximum length of the first event is selected to be combined with the low transmission rate of the physical layer. Under medium coding rate conditions, if the protocol data unit payload length exceeds the first length threshold but does not exceed the second length threshold, if the channel quality is good, the maximum length of the first event is selected in combination with the high transmission rate of the adaptive physical layer; if the channel quality is medium, the maximum length of the first event is selected in combination with the medium transmission rate of the adaptive physical layer; if the channel quality is poor, the maximum length of the second event is selected in combination with the low transmission rate of the adaptive physical layer.

[0055] In this embodiment, when the encoding rate is low and a medium-to-high transmission rate is used for RCIS PDU transmission, the two RCIS links use subevents without shared time. When the encoding rate is high and a medium-to-low transmission rate is used for lossless audio data, resulting in the RCIS PDU airtime being greater than the maximum length of the first event (subevent length), the two RCIS links use the maximum length of the first event as the maximum length of the current subevent, and the two RCIS links use subevents with shared time.

[0056] In this embodiment, as another optional embodiment, after establishing RCIG between the WMCLA transmitting device and the WMCLA terminal device, the transmission rate of the adaptive physical layer and the maximum length of the current sub-event can be adjusted in real time within each ISO Interval based on the coding rate or its corresponding SDU size. Taking two RCIS links as an example, within each ISO Interval, if the RCIS PDU load of the first RCIS link is large, lossless audio data transmission is first performed using the high transmission rate of the adaptive physical layer. If the packet loss rate exceeds a preset first threshold or transmission fails, it is then switched to a medium-low transmission rate. When switching to a medium-low transmission rate, if the maximum length of the first event is insufficient, the maximum length of the second event can be used as the maximum length of the current sub-event, thereby occupying the sub-event time of the second RCIS link. In this way, by sharing the sub-event airtime, the transmission reliability of lossless audio data is improved.

[0057] Figure 3 This is a schematic diagram of the first time slot structure of the RCIG according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the second time-slot structure of the RCIG according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the third time slot structure of the RCIG according to an embodiment of the present invention.

[0058] like Figures 3 to 5 The diagram shows a time-slot structure of an RCIG consisting of two RCIS links, labeled RCIS0 and RCIS1. The timing between RCIS0 and RCIS1 follows the interleaved mode specified by the BLE Isochronous Channels protocol. Figure 3 In the time-slot structure shown, the secondary events of the two RCIS links do not share time. Figure 4 In the time slot structure shown, the RCIS0 link uses the maximum length of the first event as the maximum length of the current secondary event, and does not occupy the secondary event time of the RCIS1 link. The RCIS1 link uses the maximum length of the second event as the maximum length of the current secondary event, and needs to occupy the secondary event time of the RCIS0 link. Figure 5 In the timeslot structure shown, the RCIS0 link uses the maximum length of the first event as the maximum length of the current secondary event, without occupying the secondary event time of the RCIS1 link. The RCIS1 link initially uses the maximum length of the first event as the maximum length of the current secondary event, without occupying the secondary event time of the RCIS0 link. After two failed transmissions of the RCIS1 link's RCIS PDU and two successful transmissions of the RCIS0 link's RCIS PDU, it switches to using the maximum length of the second event as the maximum length of the current secondary event, occupying the secondary event time of the RCIS0 link, and succeeds after two transmissions. In the figure, solid-lined secondary event boxes represent secondary events actually used, while dashed-lined boxes represent secondary events that may be used but are not actually used, such as secondary events occupied by another RCIS link or secondary events used for retransmission.

[0059] In this embodiment, as Figures 3 to 5 Within each equal-time interval, the starting point (RCIS0 AnchorPoint) of the RCIS0 link and the starting point (RCIS1 Anchor Point) of the RCIS1 link are the same whether or not the secondary event time is shared. Similarly, the secondary event interval (RCIS0 Sub_Interval) of the RCIS0 link and the RCIS1 link are the same regardless of whether the secondary event time is shared. However, the maximum length of the current secondary event for the RCIS0 link and the RCIS1 link differs depending on whether the secondary event time is shared. When the secondary event time is shared, the maximum length of the current secondary event is greater than when the secondary event time is not shared.

[0060] In this way, between or within each equal-time interval, the WMCLA transmitting device can adaptively switch the current transmission rate and maximum sub-event length of the adaptive physical layer according to changes in the coding rate or the wireless communication environment. When the WMCLA transmitting device adaptively switches the current transmission rate and maximum sub-event length of the adaptive physical layer, it does not need to negotiate with the WMLA receiver. Correspondingly, the WMLA receiver only needs to receive RCIS PDUs transmitted through the physical layer at different rates within each equal-time interval, according to the preset starting point of the RCIS0 or RCIS1 link and the corresponding sub-event interval of the RCIS0 or RCIS1 link. After receiving the RCIS PDU, the current transmission rate of the adaptive physical layer is identified based on the rate indication field in the physical layer's control header.

[0061] The wireless multi-channel audio transmission method of this embodiment transmits multi-channel audio data by using at least two reconfigurable isochronous stream links. The at least two reconfigurable isochronous stream links constitute a reconfigurable isochronous group. The at least two reconfigurable isochronous stream links dynamically adopt adaptive physical layers with different transmission rates and use sub-event transmission based on adaptive shared time to transmit the corresponding protocol data units. There is no need to switch the audio encoding rate, which can effectively improve the adaptability to the rapidly changing wireless communication environment in wireless multi-channel audio transmission and ensure the audio quality of the transmission.

[0062] Figure 6 This is another schematic flowchart illustrating a wireless multi-channel audio transmission method provided in an embodiment of the present invention. Figure 6 As shown, the process includes: S601. Establish a connection isochronous stream link with the transmitting device, wherein the transmitting device also establishes one or more connection isochronous stream links with other receiving devices, the multiple connection isochronous stream links form a connection isochronous group, at least one connection isochronous stream link supports an adaptive physical layer, the control packet header used by the adaptive physical layer includes a rate indication field, the rate indication field indicates that the current transmission rate of the adaptive physical layer is any one of a predetermined plurality of transmission rates, the transmission time of the connection isochronous group includes a series of isochronous intervals, each isochronous stream link includes a plurality of sub-event intervals in each isochronous interval; In this embodiment, as an optional implementation, when establishing each connection isochronous flow link, a link-layer connection isochronous flow request protocol data unit is sent to peripheral devices. The control data of the link-layer connection isochronous flow request protocol data unit includes: a reconfigurable connection isochronous group enable flag. The reconfigurable connection isochronous group enable flag is valid, indicating that the connection isochronous flow link supports adaptive physical layer and adaptive sub-event maximum length; The reconfigurable connection isochronous group enable flag is invalid, indicating that the connection isochronous flow link does not support adaptive physical layer and adaptive sub-event maximum length.

[0063] In this embodiment, as an optional implementation, the connection isochronous group includes a first connection isochronous flow link and a second connection isochronous flow link. The first connection isochronous stream link and / or the second connection isochronous stream link support adaptive physical layer and adaptive maximum sub-event length.

[0064] In this embodiment, the process of establishing a reconfigurable connection isochronous flow link between the receiving device and the central device is similar to that of establishing a corresponding reconfigurable connection isochronous flow link between the sending device and each of the multiple receiving devices, and will not be described in detail here.

[0065] S602. During the current isochronous interval, when receiving protocol data units at the sub-event interval of the corresponding isochronous stream link, the current transmission rate of the adaptive physical layer is adaptively identified based on the rate indication field in the control packet header used by the physical layer, thereby adaptively switching the adaptive physical layer to the corresponding transmission rate.

[0066] In this embodiment, as an optional embodiment, the sub-event starting point of each connected isochronous stream link is the same within each isochronous interval; Within each isochronous interval, the sub-event intervals for each connected isochronous stream link are the same.

[0067] In this embodiment, as an optional implementation, the control header of the adaptive physical layer includes a rate indication field, which indicates that the current transmission rate of the adaptive physical layer is any one of a predetermined plurality of transmission rates. Thus, the receiving device determines the transmission rate of the adaptive physical layer currently used by the reconfigurable connection isochronous stream link through the rate indication field in the control header, and switches to that adaptive physical layer's transmission rate for reception.

[0068] The following specific embodiment will be used to illustrate this application in detail.

[0069] Combination Figure 2When a smartphone acting as the RCIG central device establishes an RCIS link with a TWLS headset acting as an RCIG peripheral device, the first RFU bit in the transmitted LL_CIS_REQ PDU is used as the RCIG_En flag, and the RCIG_En flag is set to 1 to support the RCIG protocol. The PHY type of the physical layer parameter PHY_C_To_P in the LL_CIS_REQ PDU is set to 0b111, representing an adaptive physical layer, for example, by setting the rate indication field in the control packet header to indicate the physical layer rate: BLE HDT PHY. As an optional embodiment, the BLE HDT PHY supports at least BLE HDT3 providing a rate of 3 Mbps, BLE HDT4 providing a rate of 4 Mbps, and BLE HDT6 providing a rate of 6 Mbps.

[0070] In this embodiment, the stereo (two-channel) sampling rate is 48kHz, and the quantization bits per audio sample are 16. The left and right channel audio uses independent Golomb-Rice-based Free Lossless Audio Codecs (FLAC), with a frame length of 10ms and a coding rate varying between 320kbps and 768kbps. The RCIS PDU payload size varies between 400 bytes and 960 bytes.

[0071] The RCIG central equipment uses an adaptive physical layer that supports three transmission rates: BLE HDT3, BLE HDT4, and BLE HDT6 (corresponding to low, medium, and high transmission rates within the same physical layer, respectively). RCIG peripheral equipment uses the BLE HDT2 physical layer to respond with acknowledgment information. When the RCIS PDU payload is 400 bytes, the airtime for a BLE HDT3 RCIS PDU is 1163 µs, for a BLE HDT4 RCIS PDU it is 889 µs, and for a BLE HDT6 RCIS PDU it is 616 µs. When the RCIS PDU payload is 960 bytes, the airtime for a BLE HDT3 RCIS PDU is 2656 µs, for a BLE HDT4 RCIS PDU it is 2009 µs, and for a BLE HDT6 RCIS PDU it is 1363 µs.

[0072] In this embodiment, the isochronous interval of RCIS0 is 20ms, the number of subevents (NSE) is 6, the burst number (BN) is 2, and the flush timeout (FT) is 5. The subevent interval between RCIS0 and RCIS1 links is 3080µs. The offset between the starting points of RCIS0 and RCIS1 links is 1540µs. Both RCIS0 and RCIS1 links use BLE HDT2 physical layer to reply with acknowledgment information, and their RCIS PDU airtime is 69µs. The inter-frame space (T_IFS) is 47µs, and the minimum slot space (T_MSS) is 61µs. The maximum length of the first event for RCIS0 and RCIS1 links is 1540µs, and the maximum length of the second event is 3080µs.

[0073] When performing wireless multi-channel audio transmission If the coding rate is low and the RCIS PDU payload length does not exceed 480 bytes, the maximum length of the first event can be adaptively selected based on the wireless communication environment (channel quality) and combined with BLE HDT3, BLE HDT4, and BLE HDT6. Specifically, for good channel quality, the maximum length of the first event is selected with BLE HDT6; for medium channel quality, the maximum length of the first event is selected with BLE HDT4; and for poor channel quality, the maximum length of the first event is selected with BLE HDT3.

[0074] If the coding rate is moderate and the RCIS PDU payload length exceeds 480 bytes but does not exceed 640 bytes, the maximum length of the first event can be adaptively selected based on the wireless communication environment (channel quality) by combining it with BLE HDT4 and BLE HDT6, or by combining it with BLE HDT3. Specifically, if the channel quality is good, the maximum length of the first event is selected to be combined with BLE HDT6; if the channel quality is moderate, the maximum length of the first event is selected to be combined with BLE HDT4; and if the channel quality is poor, the maximum length of the second event is selected to be combined with BLE HDT3.

[0075] If the coding rate is high and the RCIS PDU payload length exceeds 640 bytes but does not exceed 960 bytes, the maximum length of the first event can be adaptively selected to combine with BLE HDT6, or the maximum length of the second event can be combined with BLE HDT3 and BLE HDT4, depending on the wireless communication environment (channel quality). Specifically, if the channel quality is good, the maximum length of the first event is selected to combine with BLE HDT6; if the channel quality is medium, the maximum length of the second event is selected to combine with BLE HDT4; and if the channel quality is poor, the maximum length of the second event is selected to combine with BLE HDT3.

[0076] In this embodiment, after the TWLS headset establishes RCIG with the smartphone via the BLE ACL link, when the TWLS headset receives the RCIS PDU transmitted using BLE HDT PHY, it determines whether it is BLE HDT3, BLE HDT4, or BLE HDT6 by controlling the rate indication field in the packet header, thereby adaptively switching the different transmission rates of the adaptive physical layer.

[0077] Specifically, when the payload of RCIS0 PDU is 480 bytes and the payload of RCIS1 PDU is 460 bytes, the following is adopted: Figure 3 The time slot structure uses the maximum length of the first event for both RCIS0 and RCIS1 links. The system prioritizes the maximum length of the first event and BLE HDT6. If the packet loss rate using BLE HDT6 is higher than 10%, it switches to BLE HDT4. If the packet loss rate using BLE HDT4 is higher than 10%, it switches to BLE HDT3. If the packet loss rate using BLE HDT3 is lower than 0.1%, it attempts to use BLE HDT4. If the packet loss rate using BLE HDT4 is lower than 1%, it switches to BLE HDT4. If the packet loss rate using BLE HDT4 is lower than 0.1%, it attempts to use BLE HDT6. If the packet loss rate using BLE HDT6 is lower than 1%, it remains BLE HDT6.

[0078] When the payload of the RCIS0 PDU is 470 bytes and the payload of the RCIS1 PDU is 900 bytes, and the packet loss rate of both the RCIS0 and RCIS1 links using BLE HDT4 and BLE HDT6 is higher than 10%, then... Figure 4 The time slot structure is the same, and both use BLE HDT3. The RCIS0 link uses the first event maximum length, and the RCIS1 link uses the second event maximum length. Specifically, when the payload of the RCIS0 PDU is 630 bytes and the payload of the RCIS1 PDU is 880 bytes, neither the RCIS0 nor RCIS1 link has accurate packet loss rate statistics. Figure 5The time slot structure is as follows: The RCIS0 link uses the first event maximum length and BLE HDT4. The RCIS1 link initially uses the first event maximum length and BLE HDT6, and after the first or second transmission fails, it adaptively adjusts to use the second event maximum length and BLE HDT3 or BLE HDT4.

[0079] In this way, through RCIG, WMCLA systems with TWLS as a typical application do not need to negotiate and update link parameters (including the transmission rate, sub-event interval, and maximum sub-event length) between RCIG peripheral equipment and RCIG central equipment. They can adaptively change the transmission rate and maximum sub-event length of the adaptive physical layer according to the coding rate and channel quality, thereby improving the adaptability of WMCLA transmission to rapidly changing coding rates and rapidly changing wireless communication environments while maintaining lossless audio quality. This solves the balance problem between variable coding rates and effective bandwidth in WMCLA transmission.

[0080] Based on the same inventive concept, such as Figure 7 As shown, this embodiment of the invention also provides a wireless multi-channel audio transmission device, the device comprising: A connection isochronous group construction module 701 is used to establish a connection isochronous group, wherein the connection isochronous group includes at least one connection isochronous flow link, the at least one connection isochronous flow link supports an adaptive physical layer, the control packet header used by the adaptive physical layer includes a rate indication field, the rate indication field indicates that the current transmission rate of the adaptive physical layer is any one of a predetermined plurality of transmission rates, the transmission time of the connection isochronous group includes a series of isochronous intervals, and each isochronous interval of each connection isochronous flow link includes a plurality of sub-event intervals; In this embodiment, as an optional implementation, the connection isochronous group construction module 701 sends a link-layer connection isochronous flow request protocol data unit to peripheral devices when establishing each connection isochronous flow link. The control data of the link-layer connection isochronous flow request protocol data unit includes: a reconfigurable connection isochronous group enable flag. The reconfigurable connection isochronous group enable flag is valid, indicating that the connection isochronous flow link supports adaptive physical layer and adaptive sub-event maximum length; The reconfigurable connection isochronous group enable flag is invalid, indicating that the connection isochronous flow link does not support adaptive physical layer and adaptive sub-event maximum length.

[0081] The protocol data unit transmission module 702 is used to transmit corresponding protocol data units within at least one sub-event interval of an isochronous stream link based on each connection, wherein at least one connection isochronous stream link supports adaptive sub-event maximum length. The adaptive sub-event maximum length refers to the selection of a first event maximum length and a second event maximum length based on the current encoding rate of the audio data and the current transmission rate of the adaptive physical layer. The second event maximum length is greater than the first event maximum length. The maximum air time required for the protocol data unit transmitted on at least one connection isochronous stream link that supports the adaptive sub-event maximum length is the maximum length of the current sub-event. The protocol data unit carries one or more frames of audio encoded data obtained by encoding audio data of a predetermined duration based on the current encoding rate.

[0082] In this embodiment, as an optional embodiment, the protocol data unit transmission module 702 adaptively selects one of a predetermined plurality of transmission rates as the current highest transmission rate of the adaptive physical layer based on the channel quality of the connected isochronous stream link, and determines the channel quality of the connected isochronous stream link based on the packet loss rate of the initiated protocol data unit.

[0083] Within each equal time interval, the starting point of each secondary event for each connected equal time stream link is the same, and the protocol data unit is transmitted starting from the starting point of the corresponding secondary event; Within each isochronous interval, the sub-event intervals for each connected isochronous stream link are the same.

[0084] Based on the same inventive concept, such as Figure 8 As shown, this embodiment of the invention also provides another wireless audio transmission device, the device comprising: The connection isochronous group setting module 801 is used to establish a connection isochronous stream link with the transmitting device, wherein the transmitting device also establishes one or more connection isochronous stream links with other receiving devices, the multiple connection isochronous stream links form a connection isochronous group, at least one connection isochronous stream link supports an adaptive physical layer, the control packet header used by the adaptive physical layer includes a rate indication field, the rate indication field indicates that the current transmission rate of the adaptive physical layer is any one of a predetermined plurality of transmission rates, the transmission time of the connection isochronous group includes a series of isochronous intervals, and each isochronous interval of each connection isochronous stream link includes a plurality of sub-event intervals; In this embodiment, as an optional embodiment, the connection isochronous group setting module 801 sends a link-layer connection isochronous flow request protocol data unit to the peripheral devices when establishing each connection isochronous flow link. The control data of the link-layer connection isochronous flow request protocol data unit includes: a reconfigurable connection isochronous group enable flag. The reconfigurable connection isochronous group enable flag is valid, indicating that the connection isochronous flow link supports adaptive physical layer and adaptive sub-event maximum length; The reconfigurable connection isochronous group enable flag is invalid, indicating that the connection isochronous flow link does not support adaptive physical layer and adaptive sub-event maximum length.

[0085] The protocol data unit receiving module 802 is used to adaptively identify the current transmission rate of the physical layer based on the rate indication field in the control packet header adopted by the physical layer when receiving protocol data units in the corresponding secondary event interval of the corresponding connection isochronous stream link within the current isochronous interval, thereby adaptively switching to the physical layer with the corresponding transmission rate.

[0086] In this embodiment, as an optional embodiment, the sub-event starting point of each connected isochronous stream link is the same within each isochronous interval; Within each isochronous interval, the sub-event intervals for each connected isochronous stream link are the same.

[0087] In this embodiment, as an optional implementation, each protocol data unit includes a rate indication field, which, or a physical layer indication field, identifies different physical layer rates. Thus, the receiving device determines the physical layer currently used by the reconfigurable connection isochronous stream link through the rate indication field in the control packet header of the received protocol data unit, and switches to that physical layer for reception.

[0088] Based on the same inventive concept, embodiments of the present invention also provide a storage medium storing a computer program thereon, which, when executed by a processor, implements the steps of the wireless multi-channel audio transmission method in any of the above possible implementations.

[0089] Optionally, the storage medium may be a non-transitory computer-readable storage medium, such as a ROM, random access memory (RAM), CD-ROM, magnetic tape, floppy disk, and optical data storage device.

[0090] Based on the same inventive concept, see [link to inventive concept] Figure 9 This invention also provides an electronic device, including a memory 101 (e.g., non-volatile memory), a processor 102, and a computer program stored on the memory 101 and executable on the processor 102. When the processor 102 executes the program, it implements the steps of the wireless multi-channel audio transmission method described in any of the above possible implementations, which can be equivalent to the aforementioned wireless multi-channel audio transmission device. Of course, the processor can also be used to process other data or perform calculations. This electronic device can be a PC, server, terminal, or other similar device.

[0091] like Figure 9As shown, the electronic device may also include: memory 103, network interface 104, and internal bus 105. In addition to these components, other hardware may also be included, which will not be described in detail here.

[0092] It should be noted that the aforementioned wireless multi-channel audio transmission device can be implemented by software. As a logical device, it is formed by the processor 102 of the electronic device in which it is located reading the computer program instructions stored in the non-volatile memory into the memory 103 for execution.

[0093] The embodiments of the subject matter and functional operation described in this specification can be implemented in the following ways: digital electronic circuits, tangibly embodied computer software or firmware, computer hardware including the structures disclosed in this specification and their structural equivalents, or combinations thereof. Embodiments of the subject matter described in this specification can be implemented as one or more computer programs, i.e., one or more modules of computer program instructions encoded on a tangible, non-transitory program carrier for execution by a data processing apparatus or for controlling the operation of a data processing apparatus. Alternatively or additionally, the program instructions may be encoded on artificially generated propagation signals, such as machine-generated electrical, optical, or electromagnetic signals, which are generated to encode information and transmit it to a suitable receiving device for execution by the data processing apparatus. The computer storage medium may be a machine-readable storage device, a machine-readable storage substrate, a random or serial access memory device, or combinations thereof.

[0094] The processing and logic flow described in this specification can be executed by one or more programmable computers that execute one or more computer programs to perform corresponding functions by operating on input data and generating output. The processing and logic flow can also be executed by special-purpose logic circuitry—such as FPGA (Field Programmable Gate Array) or ASIC (Application-Specific Integrated Circuit), and the device can also be implemented as special-purpose logic circuitry.

[0095] Suitable computers for executing computer programs include, for example, general-purpose and / or special-purpose microprocessors, or any other type of central processing unit. Typically, the central processing unit receives instructions and data from read-only memory and / or random access memory. The basic components of a computer include a central processing unit for implementing or executing instructions and one or more memory devices for storing instructions and data. Typically, a computer will also include one or more mass storage devices for storing data, such as disks, magneto-optical disks, or optical disks, or the computer will be operatively coupled to such mass storage devices to receive data from or transfer data to them, or both. However, a computer is not required to have such devices. Furthermore, a computer can be embedded in another device, such as a mobile phone, a personal digital assistant (PDA), a mobile audio or video player, a game console, a global positioning system (GPS) receiver, or a portable storage device such as a universal serial bus (USB) flash drive, to name a few.

[0096] Computer-readable media suitable for storing computer program instructions and data include all forms of non-volatile memory, media, and memory devices, such as semiconductor memory devices (e.g., EPROM, EEPROM, and flash memory devices), magnetic disks (e.g., internal hard disks or removable disks), magneto-optical disks, and CD-ROM and DVD-ROM disks. Processors and memory may be supplemented by or incorporated into dedicated logic circuitry.

[0097] While this specification contains numerous specific implementation details, these should not be construed as limiting the scope of any invention or the scope of the claims, but rather are primarily used to describe features of specific embodiments of a particular invention. Certain features described in the various embodiments herein may also be implemented in combination in a single embodiment. Conversely, various features described in a single embodiment may also be implemented separately in various embodiments or in any suitable sub-combination. Furthermore, while features may function in certain combinations as described above and even initially claimed in this way, one or more features from a claimed combination may be removed from that combination in some cases, and a claimed combination may refer to a sub-combination or a variation thereof.

[0098] Similarly, although the operations are depicted in a specific order in the accompanying drawings, this should not be construed as requiring these operations to be performed in the specific order shown or sequentially, or requiring all illustrated operations to be performed to achieve the desired result. In some cases, multitasking and parallel processing may be advantageous. Furthermore, the separation of various system modules and components in the above embodiments should not be construed as requiring such separation in all embodiments, and it should be understood that the described program components and systems can generally be integrated together in a single software product or packaged into multiple software products.

[0099] Thus, specific embodiments of the subject matter have been described. Other embodiments are within the scope of the appended claims. In some cases, the actions recited in the claims may be performed in a different order and still achieve the desired result. Furthermore, the processes depicted in the drawings are not necessarily shown in a specific order or sequence to achieve the desired result. In some implementations, multitasking and parallel processing may be advantageous.

[0100] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

[0101] The above are merely specific embodiments of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for transmitting wireless multi-channel audio, characterized in that, Applied to transmitting devices, including: A connection isochronous group is established, wherein the connection isochronous group includes at least one connection isochronous stream link, the at least one connection isochronous stream link supports an adaptive physical layer, the adaptive physical layer uses a control packet header that includes a rate indication field, the rate indication field indicating that the current transmission rate of the adaptive physical layer is any one of a predetermined plurality of transmission rates, the transmission time of the connection isochronous group includes a series of isochronous intervals, and each isochronous interval of each connection isochronous stream link includes a plurality of sub-event intervals; Based on each connection isochronous stream link, the corresponding protocol data unit is transmitted within at least one sub-event interval of an isochronous interval. At least one connection isochronous stream link supports adaptive sub-event maximum length. The adaptive sub-event maximum length refers to the selection of the first event maximum length and the second event maximum length based on the current encoding rate of the audio data and the current transmission rate of the adaptive physical layer. The second event maximum length is greater than the first event maximum length. The maximum air time required for the protocol data unit transmitted on at least one connection isochronous stream link that supports adaptive sub-event maximum length is the current sub-event maximum length. The protocol data unit carries one or more frames of audio encoded data obtained by encoding audio data of a predetermined duration based on the current encoding rate.

2. The wireless multi-channel audio transmission method according to claim 1, characterized in that, The connection isochronous group includes a first connection isochronous flow link and a second connection isochronous flow link. The first connection isochronous stream link and / or the second connection isochronous stream link support adaptive physical layer and adaptive maximum sub-event length.

3. The wireless multi-channel audio transmission method according to claim 1, characterized in that, The current encoding rate varies depending on the predetermined duration of audio data, the size of each frame of encoded audio data varies, and the size of the protocol data unit varies. When the current encoding rate of the audio data and the current transmission rate of the adaptive physical layer are used, if the airtime required to transmit the protocol data unit is greater than the maximum length of the first event, then the maximum length of the second event is selected as the current maximum length of the next event; if the airtime required to transmit the protocol data unit is less than or equal to the maximum length of the first event, then the maximum length of the first event is selected as the current maximum length of the next event. When the maximum length of the first event is used as the maximum length of the current secondary event, there are no secondary events with shared time between the isochronous flow links of each connection. When the maximum length of the second event is used as the maximum length of the current sub-event, then the sub-events with shared time are available between the isochronous flow links of each connection.

4. The wireless multi-channel audio transmission method according to claim 2, characterized in that, Multiple isochronous stream links coexist in time-division multiplexing mode using interleaving mode. When one or two of the first and second isochronous stream links use the maximum length of the second event as the maximum length of the current sub-event, the sub-event of the protocol data unit transmitted based on the first isochronous stream link overlaps with the sub-event of the protocol data unit transmitted based on the second isochronous stream link in the time domain. At this time, there are sub-events with shared time between the first and second isochronous stream links. When both the first and second isochronous stream links use the maximum length of the first event as the maximum length of the current secondary event, the secondary event of the protocol data unit transmitted based on the first isochronous stream link does not overlap with the secondary event of the protocol data unit transmitted based on the second isochronous stream link in the time domain. In this case, there are no secondary events with shared time between the first and second isochronous stream links. The maximum length of the second event is no greater than the interval between the second events.

5. The wireless multi-channel audio transmission method according to claim 2, characterized in that, When the first connection isochronous stream link or the second connection isochronous stream link takes the maximum length of the second event as the maximum length of the current sub-event, and the sub-event based on the protocol data unit transmitted by the first connection isochronous stream link overlaps with the sub-event based on the protocol data unit transmitted by the second connection isochronous stream link in the time domain, the sub-event executed later in the second connection isochronous stream link and the first connection isochronous stream link is left empty to avoid the sub-event executed earlier.

6. The wireless multi-channel audio transmission method according to claim 1, characterized in that, Based on the channel quality of the isochronous stream links, a predetermined number of transmission rates are adaptively selected as the current highest transmission rate for the adaptive physical layer. The channel quality of the isochronous stream link of the connection is determined based on the packet loss rate of the transmitted protocol data units.

7. The wireless multi-channel audio transmission method according to claim 1, characterized in that, Within each equal time interval, the starting point of each secondary event for each connected equal time stream link is the same, and the protocol data unit is transmitted starting from the starting point of the corresponding secondary event; Within each isochronous interval, the sub-event intervals for each connected isochronous stream link are the same.

8. The wireless multi-channel audio transmission method according to claim 1, characterized in that, The maximum length of the current event can be changed within a single time interval and / or between different time intervals. It supports changing the current transmission rate of the current physical layer within an isochronous interval and / or between different isochronous intervals.

9. The wireless multi-channel audio transmission method according to claim 1, characterized in that, When establishing each connection isochronous flow link, a link-layer connection isochronous flow request protocol data unit is sent to surrounding devices. The control data of the link-layer connection isochronous flow request protocol data unit includes: a reconfigurable connection isochronous group enable flag. The reconfigurable connection isochronous group enable flag is valid, indicating that the connection isochronous flow link supports adaptive physical layer and adaptive sub-event maximum length; The reconfigurable connection isochronous group enable flag is invalid, indicating that the connection isochronous flow link does not support adaptive physical layer and adaptive sub-event maximum length.

10. The wireless multi-channel audio transmission method according to claim 6, characterized in that, When the current channel quality of the isochronous stream link is lower than a first predetermined quality threshold, it is considered that the current channel quality of the isochronous stream link is too low to be suitable for transmission at the current transmission rate of the adaptive physical layer. The current transmission rate of the adaptive physical layer of the isochronous stream link is then changed to a lower transmission rate until the current transmission rate of the adaptive physical layer is the lowest possible transmission rate. If the current channel quality of the isochronous stream link is higher than the second predetermined quality threshold, it is considered that the current channel quality of the isochronous stream link is too high and is not suitable for the current transmission rate of the adaptive physical layer. The current transmission rate of the adaptive physical layer of the isochronous stream link is then changed to a higher transmission rate until the current transmission rate of the adaptive physical layer is the highest transmission rate.

11. A wireless multi-channel audio transmission device, characterized in that, The wireless multi-channel audio transmission device includes: A connection isochronous group construction module is used to establish a connection isochronous group, wherein the connection isochronous group includes at least one connection isochronous flow link, the at least one connection isochronous flow link supports an adaptive physical layer, the control packet header used by the adaptive physical layer includes a rate indication field, the rate indication field indicates that the current transmission rate of the adaptive physical layer is any one of a predetermined plurality of transmission rates, the transmission time of the connection isochronous group includes a series of isochronous intervals, and each isochronous interval of each connection isochronous flow link includes a plurality of sub-event intervals; The protocol data unit transmission module is used to transmit corresponding protocol data units within at least one sub-event interval of an isochronous stream link based on each connection, wherein at least one connection isochronous stream link supports adaptive sub-event maximum length. The adaptive sub-event maximum length refers to the selection of a first event maximum length and a second event maximum length based on the current encoding rate of the audio data and the current transmission rate of the adaptive physical layer. The second event maximum length is greater than the first event maximum length. The maximum air time required for the protocol data unit transmitted on at least one connection isochronous stream link that supports the adaptive sub-event maximum length is the maximum length of the current sub-event. The protocol data unit carries one or more frames of audio encoded data obtained by encoding audio data of a predetermined duration based on the current encoding rate.

12. The wireless multi-channel audio transmission device according to claim 11, characterized in that, The current encoding rate varies depending on the predetermined duration of audio data, the size of each frame of encoded audio data varies, and the size of the protocol data unit varies. The protocol data unit transmission module is also used for: When the current encoding rate of the audio data and the current transmission rate of the adaptive physical layer are used, if the airtime required to transmit the protocol data unit is greater than the maximum length of the first event, then the maximum length of the second event is selected as the current maximum length of the next event; if the airtime required to transmit the protocol data unit is less than or equal to the maximum length of the first event, then the maximum length of the first event is selected as the current maximum length of the next event. When the maximum length of the first event is used as the maximum length of the current secondary event, there are no secondary events with shared time between the isochronous flow links of each connection. When the maximum length of the second event is used as the maximum length of the current sub-event, then the sub-events with shared time are available between the isochronous flow links of each connection.

13. A method for transmitting wireless multi-channel audio, characterized in that, Applied to receiving devices, including: A connection isochronous stream link is established with the transmitting device, wherein the transmitting device also establishes one or more connection isochronous stream links with other receiving devices, the multiple connection isochronous stream links form a connection isochronous group, at least one connection isochronous stream link supports an adaptive physical layer, the control packet header used by the adaptive physical layer includes a rate indication field, the rate indication field indicates that the current transmission rate of the adaptive physical layer is any one of a predetermined plurality of transmission rates, the transmission time of the connection isochronous group includes a series of isochronous intervals, and each isochronous interval of each connection isochronous stream link includes a plurality of sub-event intervals; Within the current isochronous interval, when receiving protocol data units at the sub-event interval of the corresponding isochronous stream link, the current transmission rate of the adaptive physical layer is adaptively identified based on the rate indication field in the control packet header used by the physical layer, thereby adaptively switching the adaptive physical layer to the corresponding transmission rate.

14. The wireless multi-channel audio transmission method according to claim 13, characterized in that, Within each equal time interval, the secondary event start point is the same for each connected equal time stream link; Within each isochronous interval, the sub-event intervals for each connected isochronous stream link are the same.

15. A storage medium, characterized in that, A program or instructions are stored on a storage medium, and the program or instructions are executed by a processor to implement the steps of the wireless multi-channel audio transmission method as claimed in any one of claims 1 to 10 or 13 to 14.

16. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the steps of the wireless multi-channel audio transmission method according to any one of claims 1 to 10 or 13 to 14.

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