CN117715244A

CN117715244A - Wireless audio communication method, device and system

Info

Publication number: CN117715244A
Application number: CN202311691962.1A
Authority: CN
Inventors: 徐斌
Original assignee: Hefei Zhonggan Micro Electronic Co ltd
Current assignee: Hefei Zhonggan Micro Electronic Co ltd
Priority date: 2023-10-23
Filing date: 2023-12-05
Publication date: 2024-03-15

Abstract

The application provides a wireless audio communication method, device and system, comprising the following steps: broadcast transmitting audio data based on the broadcast communication link; periodically broadcasting based on the advertisement channel; the advertisement channel includes a periodic advertisement channel; negotiating with a second device on a periodic advertisement channel according to a pre-configured protocol to establish an ACL link when periodic broadcasting is performed; the pre-configured protocol is used for supporting bidirectional communication between the first device and the second device based on the periodic advertisement channel, and the ACL link is used for carrying out point-to-point data transmission with the second device. Therefore, the first device can negotiate with the second device on the periodic advertisement channel through periodic broadcasting during audio data broadcasting to establish an ACL link, and the first device is not required to additionally open a search window for establishing the ACL link, so that the ACL link can be quickly established between the first device and the second device, the bandwidth is saved, the development difficulty is reduced, and the user experience is improved.

Description

Wireless audio communication method, device and system

Technical Field

The embodiment of the application relates to the technical field of wireless communication, in particular to a wireless audio communication method, device and system.

Background

At present, wireless audio technology brings unconstrained free conversation and music enjoyment to people, and is widely loved by people. In particular, bluetooth low energy (Bluetooth Low Energy, BLE) Audio (Audio) technology, a synchronous isochronous channel (Isochronous Channels) protocol, that is, a point-to-point communication connection isochronous stream (Connected Isochronous Stream, CIS) link and a connection isochronous group (Connected Isochronous Group, CIG) protocol composed of a plurality of CIS links, is adopted to implement point-to-point unidirectional or bidirectional Audio transmission, and a point-to-multipoint communication broadcast isochronous stream (Broadcast Isochronous Stream, BIS) link and a broadcast isochronous group (Broadcast Isochronous Group, BIG) protocol composed of a plurality of BIS links are adopted to implement point-to-multipoint unidirectional Audio transmission, thereby bringing lower power consumption, lower cost, higher quality, lower delay and richer wireless Audio service to people.

However, the BLE protocol establishes a point-to-point communication connection, such as a BLE asynchronous connection (ACL: asynchronous Connection-oriented), when the slave device transmits a connectable advertisement packet, it is required that the master device opens a search window, i.e., the master device maintains a state of passively receiving information during the search window until the search window time expires or the connectable advertisement packet transmitted from the slave device is received. However, the BIG protocol has a shortage of time slot resources under the condition of coexistence with other multiple communication protocols, and is difficult to support to establish BLE ACL connection, which limits the use of bluetooth broadcasting technology in many application scenarios.

For example, two typical applications of BLE Audio technology today include: wireless multi-audio streaming functions typically applied with true wireless stereo (True Wireless Stereo, TWS) implemented with CIG link protocol and point-to-multipoint audio sharing functions typically applied with meta-gas broadcast (Auracast) implemented with BIG link protocol. But BIG and CIG are two different communication link protocols, and the two applications of Auracast and TWS are difficult to combine closely. If one audio device needs to be conveniently switched between the Auracast mode and the TWS mode, two different communication link protocols of BIG and CIG need to be switched, the technical implementation process is complex, the cost is high, and the user experience is poor. The BIG protocol neither supports two-way communication between master and slave devices, and lacks time slot resources for establishing BLE ACL connection when multiple protocols coexist, so that pairing and connection establishment of one BIG master device and one BIG slave device are difficult to realize, a TWS system formed by two BIG devices cannot be realized, and an application scene of flexible switching of the BIG devices between Auracast and TWS modes cannot be realized.

Disclosure of Invention

The embodiment of the application provides a wireless audio communication method, equipment and a system, which are used for at least solving the problem that the current wireless audio broadcasting technology is difficult to quickly establish point-to-point communication connection under the condition of shortage of time slot resources.

In order to solve the technical problems, the application is realized in the following way:

in a first aspect, an embodiment of the present application provides a wireless audio communication method, where the method is applied to a first device, and the method includes:

broadcast transmitting audio data based on the broadcast communication link;

based on the advertisement channel, performing periodic broadcasting; the advertisement channel comprises a periodic advertisement channel;

negotiating with a second device on the periodic advertisement channel according to a pre-configured protocol to establish an asynchronous connection ACL link while the periodic broadcast is performed; the pre-configured protocol is used for supporting bidirectional communication between the first equipment and the second equipment based on the periodic advertisement channel, and the ACL link is used for carrying out point-to-point data transmission with the second equipment.

Optionally, the method further comprises: broadcasting and transmitting broadcasting configuration information on the periodic advertisement channel when the periodic broadcasting is performed; and/or, the time starting point of each connection interval of the ACL link is the same as the time starting point of the periodic broadcast.

Optionally, the negotiating with the second device to establish an ACL link on the periodic advertisement channel according to a pre-configured protocol when the periodic broadcast is performed includes:

Broadcasting and transmitting the synchronous search data packet based on a periodic advertisement channel; the synchronous searching data packet is used for the first equipment to search surrounding second equipment;

receiving a synchronous connection request data packet fed back by the second device on the periodic advertisement channel, wherein the synchronous connection request data packet is used for the second device to request the first device to establish connection;

after receiving the synchronous connection request data packet, determining a target second device allowed to establish an ACL link, and sending a synchronous connection initialization data packet to the target second device based on the periodic advertisement channel;

receiving a synchronous connection response data packet fed back by the target second equipment on the periodic advertisement channel;

after receiving the synchronous connection response data packet, establishing an ACL link with the target second equipment;

the target second device is one of the second devices.

Optionally, the synchronous search data packet carries device address information, broadcast configuration information of the first device, and indication information for indicating that the ad mode AdvMode is a non-directional connectable type; and/or the number of the groups of groups,

the synchronous connection request data packet carries the equipment address information of the second equipment, the equipment address information of the first equipment and the indication information for indicating that the second equipment requests to pair with the first equipment and establish an ACL link; and/or the number of the groups of groups,

The synchronous connection response data packet carries the equipment address information of the first equipment and the equipment address information of the target second equipment; and/or the number of the groups of groups,

the synchronous connection initialization data packet carries the equipment address information of the first equipment, the equipment address information of the target second equipment and parameter information related to the ACL link establishment.

Optionally, the advertisement channel is configured according to bluetooth low energy BLE protocol;

the advertisement channel further comprises: a primary advertisement channel, a secondary advertisement channel;

the method comprises the steps of carrying out periodic broadcasting based on an advertisement channel, and further comprises an extended advertisement protocol data unit sent on the main advertisement channel and an auxiliary advertisement protocol data unit sent on the secondary advertisement channel;

the broadcast configuration information is broadcast isochronous group configuration information BIGinfo;

the time slot for transmitting the synchronous search data packet and the synchronous connection initialization data packet is a time slot for transmitting an AUX_SYNC_IND PDU specified by a BLE protocol;

the time slots for receiving the synchronous connection request data packet and the synchronous connection initialization data packet are time slots which are set by a BLE protocol, are after the time slots for transmitting the AUX_SYNC_IND PDU and are separated by a preset inter-packet interval duration.

Optionally, the first device is a device supporting at least a first mode, or the first device is a device supporting the first mode and supporting a second mode;

the broadcast transmitting audio data based on the broadcast communication link includes: in the first mode and/or the second mode, the first device broadcast transmits audio data based on a broadcast communication link;

the first mode is a true wireless stereo mode and the second mode is a broadcast mode.

Optionally, the method further comprises: and after the ACL link is established with the target second equipment, transmitting control information with the target second equipment based on the ACL link.

Optionally, the control information includes: audio control information associated with the audio data and/or operational status control information associated with the first device and the second device;

the audio control information includes: left and right channel audio negotiation information, and/or volume adjustment information, and/or audio operation information, the audio operation information including at least one of: audio play, audio pause, and audio fast forward;

the operating state control information includes at least one of: control information indicating to close or open the first device and/or the second device, control information indicating to bind and pair the first device and the second device, control information indicating to unpair the first device and the second device, and control information indicating to disconnect the first device and the second device.

Optionally, in the first mode, the broadcasting the audio data based on the broadcast communication link includes:

based on the broadcast communication link, broadcasting first audio data, the first audio data comprising left channel audio data and right channel audio data;

in the first mode, the method further comprises: based on the ACL link, transmitting left and right channel audio negotiation information with the target second equipment, so as to determine audio data of one channel selected by the target second equipment from the first audio data, wherein the audio data of the one channel is the left channel audio data or the right channel audio data;

in the first mode, the method further comprises: locally playing audio data of another channel which is not selected by the target second equipment;

the first mode is a true wireless stereo mode.

based on a broadcast communication link, broadcasting and transmitting second audio data, wherein the second audio data is audio data of one channel for playing by target second equipment, and the audio data of one channel is left channel audio data or right channel audio data;

In the first mode, the method further comprises: locally playing audio data of another channel which is not used for playing by the target second equipment, wherein the audio data of the other channel is right channel audio data or left channel audio data;

the first mode is a true wireless stereo mode.

Optionally, after receiving the synchronous connection request packet, determining a target second device that allows the ACL link to be established, including:

acquiring information of a second device requesting to establish an ACL link from the received synchronous connection request data packet;

and determining the target second equipment according to a user instruction or a preconfigured selection mechanism.

Optionally, the preconfigured selection mechanism includes:

if only a synchronous connection request data packet sent by one second device is received in a preset time period, determining the one second device as a target second device allowing an ACL link to be established; and/or the number of the groups of groups,

and if the synchronous connection request data packets sent by two or more second devices are received within the preset time period, the target second device is not determined.

Optionally, when the first device is a device supporting the first mode and supporting the second mode, the method further includes:

In the case of establishing an ACL link with the target second device, the first device performs the first mode;

in the case that no ACL link is established with the second device, the first device performs the second mode;

Optionally, in the case that the device information of the second device supporting the first mode is pre-stored in the first device, the negotiating with the second device to establish an ACL link on the periodic advertisement channel according to a pre-configured protocol when the periodic broadcast is performed includes:

taking the second equipment supporting the first mode as target second equipment, and sending a synchronous connection initialization data packet to the target second equipment based on the periodic advertisement channel;

the first mode is a true wireless stereo mode.

In a second aspect, an embodiment of the present application provides a wireless audio communication method, where the method is applied to a second device, and the method includes:

Receiving a periodic broadcast of the first device based on the advertising channel; the advertisement channel comprises a periodic advertisement channel;

negotiating with the first device on the periodic advertisement channel to establish an ACL link according to a pre-configured protocol upon receiving the periodic broadcast; the pre-configured protocol is used for supporting the first equipment and the second equipment to carry out bidirectional communication based on the periodic advertisement channel, and the ACL link is used for carrying out point-to-point data transmission with the first equipment;

the audio data broadcast by the first device is received based on a broadcast communication link.

Optionally, the receiving, based on the advertisement channel, the periodic broadcast of the first device includes: receiving broadcast configuration information broadcast by the first device on the periodic advertisement channel;

the receiving, based on a broadcast communication link, the first device broadcast transmission audio data includes: and receiving the audio data broadcast by the first equipment on the broadcast communication link according to the broadcast configuration information.

Optionally, the negotiating with the first device to establish an ACL link on the periodic advertisement channel according to a pre-configured protocol when receiving the periodic broadcast includes:

Receiving a synchronous search data packet broadcast transmitted by the first device on the periodic advertisement channel;

feeding back a synchronous connection request data packet to the first device based on the periodic advertisement channel, wherein the synchronous connection request data packet is used for requesting the first device to establish connection;

receiving a synchronous connection initialization data packet from the first device on the periodic advertisement channel, and determining whether the device is a target second device which allows the first device to establish an ACL link or not based on the synchronous connection initialization data packet;

and under the condition that the device is determined to be the target second device, feeding back a synchronous connection response data packet to the first device based on the periodic advertisement channel, and establishing an ACL link with the first device.

Optionally, after receiving the synchronization search data packet broadcast by the first device on the periodic advertisement channel, the method further includes:

randomly generating delay with preset duration;

and after the delay of the preset duration, if the synchronous search data packet is received again, feeding back the synchronous connection request data packet to the first equipment.

the method comprises the steps of receiving periodic broadcast of a first device based on an advertisement channel, and further comprises the steps of receiving an extended advertisement protocol data unit sent by the first device on the primary advertisement channel and receiving an auxiliary advertisement protocol data unit sent by the first device on the secondary advertisement channel.

Optionally, the second device is a device supporting at least the first mode, or the second device is a device supporting the first mode and supporting the second mode;

the receiving, based on the broadcast communication link, the audio data broadcast by the first device includes: in the first mode or the second mode, the second device receives audio data broadcast by the first device based on a broadcast communication link;

in the first mode, the method further comprises: acquiring audio data of one sound channel from the audio data, and locally playing the audio data of the one sound channel;

in the second mode, the method further comprises: playing the audio data locally;

Optionally, the method further comprises: and after the target second equipment establishes an ACL link with the first equipment, transmitting control information with the first equipment based on the ACL link.

Optionally, in the case that the device information of the first device supporting the first mode is pre-stored in the second device, the negotiating with the first device on the periodic advertisement channel to establish an ACL link according to a pre-configured protocol when receiving the periodic broadcast includes:

receiving a synchronous connection initialization data packet sent by the first equipment on the periodic advertisement channel;

as a target second device, feeding back a synchronous connection response data packet to the first device based on the periodic advertisement channel, and establishing an ACL link with the first device;

the first mode is a true wireless stereo mode.

In a third aspect, an embodiment of the present application provides a first device, which is configured to implement the wireless audio communication method in the first aspect, including: the device comprises an audio input unit, an audio processing unit, a baseband data and protocol processor and a radio frequency transceiver module;

the audio input unit is used for acquiring an audio signal;

The audio processing unit is used for processing the audio signal into audio data;

the baseband data and protocol processor is used for controlling the radio frequency transceiver module to broadcast and send the audio data based on a broadcast communication link and periodically broadcast based on an advertisement channel; the advertisement channel comprises a periodic advertisement channel;

the baseband data and protocol processor is further configured to negotiate with a second device on the periodic advertisement channel according to a pre-configured protocol to establish an asynchronous connection ACL link when the periodic broadcast is performed; the pre-configured protocol is used for supporting bidirectional communication between the first equipment and the second equipment based on the periodic advertisement channel, and the ACL link is used for carrying out point-to-point data transmission with the second equipment.

In a fourth aspect, an embodiment of the present application provides a second device, configured to implement the wireless audio communication method in the second aspect, including: the base band data and protocol processor and the radio frequency transceiver module;

the baseband data and protocol processor is used for controlling the radio frequency transceiver module to receive periodic broadcast of the first device based on the advertisement channel; the advertisement channel comprises a periodic advertisement channel;

The baseband data and protocol processor is further configured to negotiate with the first device on the periodic advertisement channel according to a pre-configured protocol to establish an ACL link when receiving the periodic broadcast; the pre-configured protocol is used for supporting bidirectional communication between the first equipment and the second equipment based on the periodic advertisement channel, and the ACL link is used for carrying out point-to-point data transmission with the first equipment;

the baseband data and protocol processor is further configured to control the radio frequency transceiver module to receive audio data broadcast by the first device based on a broadcast communication link.

In a fifth aspect, an embodiment of the present application provides an audio transmission system, including:

a first device as claimed in the third aspect;

the second device of the fourth aspect.

Therefore, in the embodiment of the application, during the audio data broadcasting process, the first device can negotiate with the second device on the periodic advertisement channel through periodic broadcasting to establish an ACL link for carrying out point-to-point data transmission with the second device, and the first device is not required to additionally open a search window for establishing the ACL link, so that the ACL link can be quickly established between the first device and the second device, the bandwidth is saved, the development difficulty is reduced, and the user experience degree is improved.

Drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the application. Also, like reference numerals are used to designate like parts throughout the figures. In the drawings:

fig. 1 is a flowchart of a wireless audio communication method according to an embodiment of the present application;

fig. 2 is a flowchart of a wireless audio communication method according to an embodiment of the present application;

fig. 3 is a schematic diagram of a TWS audio system according to an embodiment of the disclosure;

fig. 4 is a schematic diagram of a common extended advertisement payload format in BLE Audio specification;

fig. 5 is a schematic diagram of an extended packet header format according to an embodiment of the present application;

fig. 6 is a schematic diagram of an extended packet header flag bit according to an embodiment of the present application;

fig. 7 is a schematic load structure diagram of a synchronous connection initialization packet according to an embodiment of the present application;

fig. 8 is a schematic diagram of an LL Data domain structure of a synchronous connection initialization packet payload according to an embodiment of the present application;

fig. 9 is a schematic diagram of a slot structure for establishing an ACL link according to an embodiment of the present application;

Fig. 10 is a flowchart of a wireless audio communication method according to an embodiment of the present application;

fig. 11 is a flowchart of a wireless audio communication method according to an embodiment of the present application;

fig. 12 is a schematic structural diagram of a first device or a second device according to an embodiment of the present application;

fig. 13 is a schematic structural diagram of a wireless audio communication system according to an embodiment of the present application;

fig. 14 is a block diagram of an electronic device according to an embodiment of the present application.

Detailed Description

The following description of the embodiments of the present application will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are some, but not all, of the embodiments of the present application. All other embodiments, which can be made by one of ordinary skill in the art based on the embodiments herein without making any inventive effort, are intended to be within the scope of the present application.

Fig. 1 shows a flowchart of a wireless audio communication method according to an embodiment of the present application, where the method shown in fig. 1 is applicable to a first device, and the method includes:

step S101, based on a broadcast communication link, audio data is broadcast and sent;

Step S102, based on the advertisement channel, periodic broadcasting is carried out;

negotiating with the second device on the periodic advertisement channel according to a pre-configured protocol to establish an asynchronous connection ACL link when the periodic broadcast is performed in step S102;

the pre-configured protocol is used for supporting bidirectional communication between the first device and the second device based on the periodic advertisement channel, and the ACL (Asynchronous Connection-ordered, asynchronous connection) link is used for point-to-point data transmission with the second device.

In some embodiments, the audio data in the audio stream may be broadcast based on the broadcast equation set BIG protocol that is currently commonly used, or may be transmitted based on other similar broadcast communication protocols.

In addition, during broadcasting of the audio data, the broadcasting will also be periodically broadcast based on the advertisement channel to periodically broadcast the transmission broadcast configuration information. After any slave device receives the broadcast configuration information, the slave device can synchronize to the broadcast time slot according to the broadcast configuration information, so as to receive the audio stream broadcasted by the broadcast master device. In general, the broadcast configuration information may include various parameters such as a broadcast interval, a size of a data frame, a number of retransmissions, a scheduling manner, and the like. It can be understood that when the BIG protocol is adopted, the broadcast configuration information is broadcast isochronous group configuration information BIG.

In some embodiments, the method further comprises: and broadcasting and transmitting the broadcast configuration information on the periodic advertisement channel when the periodic broadcast is performed.

In one possible implementation, as shown in fig. 2, in step S102, negotiating with the second device to establish an ACL link on the periodic advertisement channel according to a pre-configured protocol while the periodic broadcast is performed, includes:

step S1022, broadcasting and transmitting a synchronous search data packet based on the periodic advertisement channel, wherein the synchronous search data packet is used for the first equipment to search surrounding second equipment;

after receiving the synchronous search data packet, the second device can learn that the first device allows negotiation to establish an ACL link according to the synchronous search data packet.

Step S1023, receiving a synchronous connection request data packet fed back by the second equipment on the periodic advertisement channel;

the synchronous connection request data packet is used for requesting the second equipment to establish connection to the first equipment;

step S1024, after receiving the synchronous connection request data packet, determining a target second device allowed to establish an ACL link, and transmitting a synchronous connection initialization data packet to the target second device based on a periodic advertisement channel;

As a specific embodiment, information of the second device requesting to establish the ACL link may be obtained from the received synchronous connection request packet; and determining the target second device according to a user instruction or a preconfigured selection mechanism.

Step S1025, receiving a synchronous connection response data packet fed back by the target second equipment on the periodic advertisement channel;

step S1026, after receiving the synchronous connection response data packet, an ACL link is established with the target second device.

Wherein the target second device is one of the second devices.

In some embodiments, the broadcast configuration information and the sync search packet may be time-shared broadcast on the periodic advertisement channel. In other embodiments, the synchronization search packet may also be made to carry the broadcast configuration information.

In some embodiments, the synchronization search packet may further carry device address information of the first device, so that after the second device receives the synchronization search packet, the second device may feed back a synchronization connection request packet based on the device address information of the first device.

In some embodiments, the synchronous search packet may further carry indication information for indicating that the ad mode AdvMode is a non-directional connectable type.

In some embodiments, the synchronous connection request packet may carry device address information of the second device, device address information of the first device, and indication information for indicating that the second device requests pairing with the first device and establishment of an ACL link.

In some specific embodiments, the synchronous connection response packet may carry device address information of the first device and device address information of the target second device.

In some embodiments, the synchronization connection initialization packet may carry device address information of the first device, device address information of the target second device, and parameter information related to the ACL link establishment.

The pre-configured protocol may be referred to herein as the BPA (Bidirectional Periodic Advertising, bi-directional periodic advertisement) protocol.

In the embodiment of the application, the first device can negotiate with the second device on the periodic advertisement channel through periodic broadcasting during audio data broadcasting to establish an ACL link for carrying out point-to-point data transmission with the second device, and the first device is not required to additionally open a search window for establishing the ACL link, so that the ACL link can be quickly established between the first device and the second device, the bandwidth is saved, the development difficulty is reduced, and the user experience is improved.

Furthermore, the wireless audio communication method provided in the embodiment of the application can also realize the free switching of the audio device between the true wireless stereo mode and the broadcast mode, and can also realize the true wireless stereo function based on audio broadcasting. In the real wireless stereo (TWS) mode, the two audio devices realize the separate use of audio data of different channels based on point-to-point wireless communication links; in the broadcast mode, one audio device transmits audio data to the other audio device in a broadcast manner.

The first mode is defined herein as the true wireless stereo mode and the second mode is defined herein as the broadcast mode.

The first device is a device supporting at least a first mode, or the first device is a device supporting the first mode and supporting a second mode;

in the case that the first device is a device supporting at least the first mode, the first device transmits audio data in a broadcast based on a broadcast communication link.

In the case that the first device is a device supporting a first mode and supporting a second mode, the first device broadcasts and transmits audio data based on a broadcast communication link in both the first mode and the second mode.

When the first device is a device supporting a first mode and supporting a second mode, the wireless audio communication method further comprises:

in the case of establishing an ACL link with the target second device, the first device performs the first mode; the first device performs the second mode without establishing an ACL link with a second device.

It will be appreciated that the first device, after establishing an ACL link with the second device, may perform point-to-point transmission of various information based on the ACL link. For example, control data or audio data, etc. may be transmitted. The first device and the second device perform point-to-point data transmission based on the ACL link, and may or may not transmit on the periodic advertisement channel, for example: the peer-to-peer data transmission with the second device may be performed based on a pre-configured specific channel, which is not specifically limited in this application.

In a specific embodiment, the wireless audio communication method further includes: and after the ACL link is established with the target second equipment, transmitting control information with the target second equipment based on the ACL link.

The control information may include: audio control information associated with the audio data and/or operational status control information associated with the first device and the second device;

The wireless audio communication method of the embodiment supports additional establishment of ACL links to realize point-to-point data transmission while audio broadcasting, which effectively expands the application range of the existing wireless audio broadcasting technology and provides support for realizing new functions. For example, the TWS application as described above is implemented, and both the TWS application and the Auracast application are implemented, and free switching is achieved, bidirectional control in audio broadcasting is achieved, privacy protection in audio broadcasting is achieved, and so on.

In some embodiments, the first device may implement a true wireless stereo function based on audio broadcasting, wherein:

in a first mode, the broadcasting the transmitted audio data based on the broadcast communication link includes: based on the broadcast communication link, broadcasting first audio data, the first audio data comprising left channel audio data and right channel audio data;

in the first mode, the method further comprises: and playing the audio data of the other channel which is not selected by the target second device locally.

In other embodiments, the first device may implement a true wireless stereo function based on audio broadcasting, wherein:

in a first mode, the broadcasting the transmitted audio data based on the broadcast communication link includes: based on a broadcast communication link, broadcasting and transmitting second audio data, wherein the second audio data is audio data of one channel for playing by target second equipment, and the audio data of one channel is left channel audio data or right channel audio data;

In the first mode, the method further comprises: and locally playing audio data of another channel which is not used for playing by the target second equipment, wherein the audio data of the other channel is right channel audio data or left channel audio data.

It can be appreciated that when the first device executes the second mode, the first device may broadcast audio data and perform periodic broadcast according to an existing or future broadcast communication protocol, for example, in the second mode, the first device implements an Auracast application, which is not described herein.

Embodiments of the present application will be further described below with a specific application scenario in which a TWS function is implemented based on the bluetooth low energy BLE protocol.

Referring to fig. 3, a schematic diagram of a TWS audio system is shown. Is composed of a BIG master device (first device) supporting TWS mode and a BIG slave device (second device) supporting TWS mode. The TWS mode supporting BIG master and TWS mode supporting BIG slave establish a bi-directional communication link between the TWS mode supporting BIG master and TWS mode supporting BIG slave through a bi-directional periodic advertisement (BPA: bidirectional Periodic Advertising) protocol, facilitating the TWS pairing and establishing a BLE asynchronous connection (ACL: asynchronous Connection-oriented) link between the TWS mode supporting BIG master and TWS mode supporting BIG slave and facilitating the switching between TWS and Auracast modes. After the TWS pairing is successful, the BIG device switches from the Auracast mode to the TWS mode. The BIG device with successful TWS pairing is called TWS device, the BIG master with successful TWS pairing is called TWS master, and the BIG slave with successful TWS pairing is called TWS slave. The TWS master device transmits audio data to the TWS slave device through the BIG protocol. Wherein, the TWS master device and the TWS slave device mutually connect and negotiate to respectively play the audio of different channels, one left channel and one right channel, thereby forming a true wireless stereo (TWS: true Wireless Stereo) function. The audio data sent by the TWS master to the TWS slave via the BIG protocol may be either two channels or one of the channels. After the TWS mode is switched to the Auracast mode, the TWS master is called a BIG master and the TWS slave is called a BIG slave.

It will be appreciated that the TWS audio system may also be constituted by one master device (first device) supporting only TWS mode and one slave device (second device) supporting only TWS mode. In this case, neither device needs to perform mode switching.

In some embodiments, the broadcast transmission of the audio data may be performed following the BLE BIG protocol, i.e. the first device broadcasts the BIS PDU carrying the audio data in a broadcast isochronous stream event occurring at each isochronous interval.

Likewise, the advertisement channel may also be configured according to the BLE protocol. The advertisement channel includes, in addition to a periodic advertisement (Periodic Advertising) channel: primary ad channel, secondary ad channel.

In the prior art, according to BLE protocol, BIG slave device synchronizes BIG master device and obtains BIG link information (BIG info) by BIG master device transmitting extended advertisement (adv_ext_ind) protocol data unit (Protocol Data Unit, PDU) on main advertisement (Primary Advertising) channel, auxiliary advertisement (aux_adv_ind) PDU transmitted on secondary advertisement (Secondary Advertising) channel, synchronization (aux_sync_ind) PDU transmitted on periodic advertisement (Periodic Advertising) channel, thereby receiving audio data carried by BIG PDU. Similarly, the first device in the first mode periodically broadcasts based on the advertisement channel, further comprising transmitting an extended advertisement protocol data unit on the primary advertisement channel, transmitting a secondary advertisement protocol data unit on the secondary advertisement channel, and transmitting a synchronization search data packet on the periodic advertisement channel. In addition, in the case of performing the periodic broadcast, the broadcast configuration information broadcast-transmitted on the periodic advertisement channel may be broadcast isochronous group configuration information big. The first device performs periodic broadcast of the BLE protocol in a second mode.

Accordingly, the second device synchronizes the first device through an extended advertisement (adv_ext_ind) PDU transmitted by the first device on a primary advertisement (Primary Advertising) channel, an auxiliary advertisement (aux_adv_ind) PDU transmitted on a secondary advertisement (Secondary Advertising) channel, a synchronization SEARCH (sync_search) PDU (synchronization SEARCH packet) or a synchronization (aux_sync_ind) PDU transmitted on a periodic advertisement (Periodic Advertising) channel, and obtains the big fo, thereby receiving audio data carried by the big PDU.

In some embodiments, the time start of each connection interval of the ACL link is the same as the time start of the periodic broadcast to enable time division multiplexed coexistence of ACL connections with other communication links.

In some embodiments, the time slot for transmitting the synchronization search packet and the synchronization connection initialization packet is a time slot specified by BLE protocol for transmitting aux_sync_ind PDU; the time slots for receiving the synchronous connection request data packet and the synchronous connection initialization data packet are time slots which are set by a BLE protocol, are after the time slots for transmitting the AUX_SYNC_IND PDU and are separated by a preset inter-packet interval duration.

When the first device or the second device supports two modes at the same time, mode switching can be performed, and when the first device is switched to the first mode, a point-to-point bidirectional communication link is quickly established, and TWS pairing is completed. The mode switching can be triggered manually by a user or automatically according to a pre-configured mechanism.

Or when the first device or the second device only supports the first mode, after receiving the instruction for entering the first mode, the point-to-point bidirectional communication link can be quickly established, and TWS pairing is completed. The instruction for entering the first mode may be triggered manually by a user, or may be triggered automatically according to a pre-configured mechanism.

As a specific embodiment, the above-mentioned data packets sync_search_pdu, sync_connect_req PDU, and sync_connect_rsp PDU may have a structure similar to that of aux_sync_ind PDU of BLE Audio protocol, for example, all use the common extended advertisement payload format (Common Extended Advertising Payload Format) shown in fig. 4 in the BLE Audio (bluetooth low energy Audio technology) specification. The advertisement packet includes a 6bits Extended packet Header length (Extended Header Length), a 2bits advertisement mode (AdvMode), a 0-63 byte Extended packet Header (Extended Header), and a maximum of 254 bytes advertisement data (AdvData). Further, fig. 5 shows an extended header format, possibly including Extended Header Flags, advA, targetA, CTEInfo, ADI, auxPtr, syncInfo, txPower and ACAD fields. Extended Header Flags is an extension packet header flag bit, as shown in fig. 6, each bit corresponds to an extension packet header field, a bit set to 1 indicates that the extension packet header has a corresponding field, and a bit set to 0 indicates that the extension packet header does not have a corresponding field. AdvA represents the device address of the advertisement delivery device; targetA represents the device address of the target device; CTEInfo represents constant pitch extension (Constant Tone Extension, CTE) information; ADI represents advertisement data information; auxgtr represents an auxiliary advertisement pointer; syncInfo represents synchronization information; txPower represents the transmit power; ACAD represents additional controller advertisement data (Additional Controller Advertising Data). And the aux_sync_ind PDU carries BIG information (BIG info) through ACAD.

The sync_search PDU, sync_connect_req PDU, sync_connect_rsp PDU and aux_sync_ind PDU differ in the content of the Extended Header and AdvMode.

Specifically, the sync_search PDU carries at least device address information of the first device, group configuration information bitinfo during broadcasting, and indication information for indicating that the advertisement mode AdvMode is a non-directional connectable type. The sync_search PDU differs from the aux_sync_ind PDU in that bit0 of Extended Header Flags of the sync_search PDU is set to 1, indicating that its extension header contains an AdvA field, where AdvA is the device address of the first device. Other field values of the SYNC_SEARCH PDU are the same as those of the AUX_SYNC_IND PDU, and BIGInfo is contained in the ACAD field. AdvMode is set to 0b01, indicating a non-directional connectable type (Connectable Undirected). The sync_search PDU provides the second device with the BIGInfo similar to the aux_sync_ind PDU, and is also used for the first device to SEARCH for surrounding second devices.

The sync_connect_req PDU carries at least device address information of the second device, device address information of the first device, and indication information for indicating that the second device requests pairing with the first device and establishment of an ACL link. The sync_connect_req PDU differs from the aux_sync_ind PDU in that bit0 and bit1 of Extended Header Flags of the sync_connect_req PDU are both set to 1, indicating that its extension header contains two fields, advA and TargetA, where AdvA is the device address of the second device and TargetA is the device address of the first device. However, the ACAD field of the SYNC_CONNECT_REQ PDU does not contain BIGInfo, and the other field value is the same as that of the AUX_SYNC_IND PDU. AdvMode is set to 0b11, indicating the connection request type (Connection Request). The AdvData of the sync_connect_req PDU may also carry information such as a device name. The sync_connect_req PDU is used for the second device to request pairing with the BIG master supporting TWS mode and to establish BLE ACL connection.

The sync_connect_rsp PDU carries at least the device address information of the first device, the device address information of the target second device. The definition of the sync_connect_rsp PDU is the same as that of the auxiliary connection response (aux_connect_rsp) PDU of BLE Audio specification, and bit0 and bit1 of Extended Header Flags of the sync_connect_rsp PDU are set to 1, which indicates that its extension packet header contains two fields, advA and TargetA, where AdvA is the device address of the target second device, and TargetA is the device address of the first device. AdvMode is set to 0b00, indicating the connection response type (Connection Response). The sync_connect_rsp PDU is used for the target second device to respond to or acknowledge the BLE ACL connection initiated by the first device.

The sync_connect_init PDU carries at least device address information of the first device, device address information of the target second device, and parameter information related to ACL link establishment. The sync_connect_init PDU is the same as the connect_ind PDU used for initializing the connection in the BLE protocol, and as shown in fig. 7, the sync_connect_init PDU payload structure includes InitA as a device address supporting the first device, targetA as a device address of the target second device, and LLData as a parameter for establishing the BLE ACL connection. The parameter definition in LLData is identical to the parameter definition of LLData of CONNECT_IND PDU in BLE protocol (as shown in FIG. 8), and will not be repeated here. It should be noted that, the Access Address is an Access Address of the BLE ACL connection, and is randomly generated each time a connection is established. Optionally, in the embodiment of the present application, winSize is set to 0, so that the starting point of each connection interval of the newly established BLE ACL link is the same as the starting point of the periodic advertisement. Interval is the connection Interval (Connection Interval) of the newly established BLE ACL link, which in this embodiment is equal to the periodic broadcast Interval, or an integer multiple of the periodic broadcast Interval.

In the following, a specific application scenario is introduced according to a pre-configured protocol shown in fig. 2 in the process of negotiating with a second device to establish an ACL link on a periodic advertisement channel, and in this application scenario, a first device may support a first mode and a second mode for a BIG master device supporting a TWS mode, and a second device may support at least the first mode for a slave device supporting the TWS mode.

After the TWS mode supporting BIG master device controls to enter the TWS mode through, for example, a User Interface (UI), the aux_sync_ind PDU is replaced with the sync_search PDU on the periodic advertisement (Periodic Advertising) channel, allowing the TWS mode supporting BIG slave device to reply to the sync_connect_req PDU after receiving the sync_search PDU, requesting to establish a connection. After receiving the sync_connect_req PDU sent by the BIG slave device supporting the TWS mode, the BIG master device supporting the TWS mode sends a sync_connect_init PDU to the BIG slave device supporting the TWS mode to initialize BLE ACL connection (at this time, the first device has determined the target second device, and the address information of the target second device is carried in the sync_connect_init PDU, which is specifically described in the possible implementation modes that follow). After the BIG slave device supporting the TWS mode (the target second device at this time) replies to the sync_connect_rsp PDU confirming that BLE ACL connection is agreed to be established, the BIG master device supporting the TWS mode becomes the TWS master device, the BIG slave device supporting the TWS mode becomes the TWS slave device, and BLE ACL link transceiving is started. If the BLE ACL link fails to transceive or is abnormally broken, the TWS master device again sends SYNC_CONNECT_INIT PDUs to the TWS slave device to reinitialize the BLE ACL connection.

As shown in fig. 9, a schematic diagram of a slot structure for establishing an ACL link is shown. The BIG master device supporting the TWS mode transmits a SYNC_SEARCH PDU according to a time slot of a BIG protocol transmitting an AUX_SYNC_IND PDU on a periodic advertisement (Periodic Advertising) channel, and after the BIG slave device supporting the TWS mode synchronizes with the BIG master device supporting the TWS mode and receives the SYNC_SEARCH PDU, an interval T_IFS replies to the SYNC_CONNECT_REQ PDU requesting to establish a connection, wherein T_IFS is an inter-packet interval (Time of Inter Frame Space), and T_IFS is equal to 150us according to a BLE protocol. After obtaining the device address through the sync_connect_req PDU sent by the BIG slave device supporting the TWS mode, the BIG master device supporting the TWS mode sends the sync_connect_init PDU in the timeslot of sending the aux_sync_ind PDU according to the BIG protocol on the periodic advertisement (Periodic Advertising) channel, and it should be noted that, for convenience of illustration, it is assumed that the BIG master device supporting the TWS mode sends the sync_connect_init PDU after receiving the next periodic broadcast interval of the sync_connect_req PDU (hereinafter referred to as BPA interval), in practical application, the sync_connect_init PDU may be sent after a plurality of BPA intervals, and the BIG slave device supporting the TWS mode replies the sync_connect_rsp PDU after receiving the sync_connect_init PDU, so as to establish BLE ACL connection according to the parameters of LLData in the sync_connect_init PDU.

In addition, as shown in fig. 9, the transmission Window Delay (Window Delay) is equal to 1.25ms as defined by BLE protocol, and winoffset is equal to the BPA Interval (BPA Interval) minus the value of Window Delay. After the BIG master device supporting the TWS mode is switched to the TWS master device (i.e. the BIG master device supporting the TWS mode is in the TWS mode), a BLE ACL PDU (M > S as shown in fig. 9) is sent on a periodic advertisement (Periodic Advertising) channel according to a time slot of sending AUX_SYNC_IND PDUs by the BIG protocol, the BIG slave device supporting the TWS mode is switched to the TWS slave device (the BIG slave device supporting the TWS mode is in the TWS mode), and after receiving the BLE ACL PDU, a BLE ACL PDU (S > M as shown in fig. 9) is replied by an interval T_IFS, namely, an ACL link is used for carrying out point-to-point data transmission between the first device and the second device, and a BLE ACL connection transceiving mode between the TWS master device and the TWS slave device follows the BLE protocol.

In one possible implementation, after receiving the synchronous connection request packet, determining the target second device that is allowed to establish the ACL link includes: acquiring information of a second device requesting to establish an ACL link from the received synchronous connection request data packet; and determining the target second equipment according to the user instruction or a preconfigured selection mechanism.

While the preconfigured selection mechanism includes: 1. if only a synchronous connection request data packet sent by one second device is received in a preset time period, determining the one second device as a target second device allowing the establishment of an ACL link; and/or 2, if the synchronous connection request data packets sent by two or more second devices are received within a preset time period, the target second device is not determined. In addition to the two automatic selection mechanisms, the target second device may be manually determined, that is, if synchronous connection request data packets sent by a plurality of second devices are received, the names of the second devices may be displayed on the display interface of the first device, and the user may manually select the target second device from the second device by sending a selection instruction (such as a click operation) to the first device.

In some embodiments, in order to prevent interference caused by multiple two-mode-capable BIG slaves transmitting sync_connect_req PDUs simultaneously, the two-mode-capable BIG slaves randomly generate a certain delay after receiving sync_search PDUs, i.e. send sync_connect_req PDUs after receiving sync_search PDUs again after multiple BPA intervals.

In one possible implementation, as shown in fig. 10, in the case where device information of the second device supporting the first mode is stored in the first device in advance, negotiating with the second device to establish an ACL link on a periodic advertisement channel according to a pre-configured protocol when periodic broadcasting is performed, including:

Step S1001, taking a second device supporting the first mode as a target second device;

step S1002, a synchronous connection initialization data packet is sent to a target second device based on a periodic advertisement channel;

step S1003, receiving a synchronous connection response data packet fed back by the target second device on the periodic advertisement channel;

step S1004, after receiving the synchronous connection response data packet, an ACL link is established with the target second equipment.

Wherein the first mode is a true wireless stereo mode.

In the method shown in fig. 1, the device information of the second device supporting the first mode may be stored in advance in the first device, specifically, the device information of the second device supporting the first mode may be stored when the ACL link is established, may be stored when the first device is factory set, may also be stored in advance in a certain second device designated by the user, and may be a device address, a device name, or the like.

For example, after a BIG master device supporting the TWS mode and a BIG slave device supporting the TWS mode pair to each other and establish a connection, the device address and the device name of the other party may be memorized or saved, and the TWS mode may be saved. Alternatively, the TWS device that stores the TWS mode may be either a TWS master or a TWS slave. After entering the TWS mode, the TWS equipment with the audio source is automatically switched to the TWS master equipment, and the TWS equipment without the audio source is automatically switched to the TWS slave equipment. The audio source includes local playing, wired playing, wireless playing, etc., for example, when the TWS device is wirelessly connected with the smart phone to play music, the TWS device is automatically switched to the TWS master device, and the TWS master device plays one channel and broadcasts the other channel to the TWS slave device for playing.

In some specific embodiments, after the TWS master device (the first device that enters the TWS mode) and the TWS slave device (the target second device that enters the TWS mode) start transceiving of the BLE ACL link, the TWS master device and the TWS slave device may negotiate an encryption or update key of the BIS PDU, so as to prevent other BIG slave devices (the remaining second devices) from receiving the BIS PDU sent by the TWS master device.

In some embodiments, after the TWS master (the first device that enters the TWS mode) starts BLE ACL link transceiving with the TWS slave (the target second device that enters the TWS mode), the TWS master may stop sending adv_ext_ind PDUs, aux_adv_ind PDUs, and sync_search PDUs, thereby preventing other BIG slaves from synchronizing the TWS master and receiving the BIS PDUs sent by the TWS master.

When the TWS master device is controlled to be switched to an Auracast mode, the TWS master device actively disconnects BLE ACL connection with the TWS slave device, the TWS master device is restored to be a BIG master device supporting the TWS mode, and ADV_EXT_IND PDU, AUX_ADV_IND PDU and AUX_SYNC_IND PDU are restored to be sent, so that the BIG slave device can conveniently search and synchronize, and the description is omitted. That is, when the broadcasting mode is restored, only a simple restoration to the advertising channel based on the BIG protocol is required to perform the periodic broadcasting.

In summary, in the embodiment of the present application, when periodic broadcast is performed, the method of negotiating with the second device to establish an ACL link on the periodic advertisement channel according to a pre-configured protocol, compared to a method of establishing BLE ACL connection through BLE protocol (in a method of establishing BLE ACL connection through BLE protocol, BLE ACL slave device sends connectable advertisement packets, and BLE ACL master device is required to open a search window, but BIG master device is required to send audio data packets through BIG protocol, especially when time division multiplexing coexistence with a Classic BT sound source is required, time slot resources for the search window are less, connection establishment is difficult and connection establishment is slow).

In addition, the first device can perform bidirectional communication with the second device based on the ACL link to transmit control information, and can assist in realizing TWS functions and other control functions, thereby expanding the application range of BIG link protocol.

Fig. 11 shows a wireless audio communication method according to an embodiment of the present application, where the method is applied to a second device, and the method includes:

step 1101, receiving a periodic broadcast of the first device based on the advertisement channel;

negotiating with the first device on the periodic advertisement channel according to a pre-configured protocol to establish an ACL link when receiving the periodic broadcast;

Step S1102, receiving audio data broadcast by the first device based on the broadcast communication link.

The advertisement channel comprises a periodic advertisement channel, a pre-configured protocol is used for supporting the first equipment and the second equipment to carry out bidirectional communication based on the periodic advertisement channel, and the ACL link is used for carrying out point-to-point data transmission with the first equipment.

In one possible implementation, receiving a periodic broadcast by a first device based on an advertising channel, includes: on a periodic advertisement channel, receiving broadcasting isochronous group configuration information BIGInfo transmitted by a first device in a broadcasting way; receiving, based on the broadcast communication link, broadcast transmission audio data by the first device, comprising: and receiving the audio data broadcast and transmitted by the first device on a broadcast communication link according to the broadcast isochronous group configuration information BIGInfo.

In one possible implementation, the advertising channel is configured according to the bluetooth low energy BLE protocol; the advertisement channel also comprises: a primary advertisement channel, a secondary advertisement channel; the method further includes receiving, based on the advertisement channel, a periodic broadcast by the first device, and further comprising receiving, on the primary advertisement channel, an extended advertisement protocol data unit transmitted by the first device, and receiving, on the secondary advertisement channel, a supplemental advertisement protocol data unit transmitted by the first device.

It should be noted that, the detailed description of the above process is the same as the description of the embodiment of the method shown in fig. 1, and will not be repeated here.

In one possible implementation, negotiating with a first device to establish an ACL link on a periodic advertisement channel according to a pre-configured protocol upon receiving a periodic broadcast, comprises: receiving a synchronous search data packet broadcast transmitted by a first device on a periodic advertisement channel; feeding back a synchronous connection request data packet to the first device based on the periodic advertisement channel, wherein the synchronous connection request data packet is used for requesting the first device to establish connection; receiving a synchronous connection initialization data packet from the first device on the periodic advertisement channel, and determining whether the device is a target second device which allows the first device to establish an ACL link or not based on the synchronous connection initialization data packet; and under the condition that the device is determined to be the target second device, feeding back a synchronous connection response data packet to the first device based on the periodic advertisement channel, and establishing an ACL link with the first device.

It should be noted that, the detailed description of the above process is the same as the description of the embodiment of the method shown in fig. 3, and will not be repeated here.

In one possible implementation, after receiving the synchronization search packet broadcast by the first device on the periodic advertisement channel, the method further includes: randomly generating delay with preset duration; after a delay of a preset duration, if the synchronous search data packet is received again, the synchronous connection request data packet is fed back to the first device.

In order to prevent the plurality of second devices from interfering with each other by transmitting the synchronization connection request packet at the same time, the second devices randomly generate a certain delay after receiving the synchronization search packet, that is, after receiving the synchronization search packet again after receiving a plurality of BPA intervals (intervals are connection intervals of the newly established BLE ACL link).

In one possible implementation, the second device is a device that supports at least the first mode, or the second device is a device that supports the first mode and supports the second mode;

the receiving, based on the broadcast communication link, audio data broadcast by the first device includes: in the first mode or the second mode, the second device receives audio data broadcast by the first device based on the broadcast communication link;

in the first mode, the method further comprises: acquiring audio data of one sound channel from the audio data, and locally playing the audio data of one sound channel;

in a second mode, the method further comprises: playing the audio data locally; the first mode is a true wireless stereo mode and the second mode is a broadcast mode.

In one possible implementation, the method further includes: after the second device as a target establishes an ACL link with the first device, control information is transmitted with the first device based on the ACL link.

In one possible implementation, in a case where device information of a first device supporting the first mode is stored in advance in a second device, negotiating with the first device on a periodic advertisement channel to establish an ACL link according to a pre-configured protocol when receiving a periodic broadcast, comprising:

receiving a synchronous connection initialization data packet sent by a first device on a periodic advertisement channel;

as a target second device, feeding back a synchronous connection response data packet to the first device based on the periodic advertisement channel, and establishing an ACL link with the first device; the first mode is a true wireless stereo mode.

After the first device and the second device pair to form a TWS device and establish a connection, the first device and the second device may memorize or store the device address and the device name of the other party and store the TWS mode. After the TWS device storing the TWS mode is restarted, the TWS mode is automatically restored, and the TWS master device establishes connection with the TWS slave device by directly transmitting the SYNC_CONNECT_INIT PDU without transmitting the SYNC_SEARCH PDU while transmitting the ADV_EXT_IND PDU (extended advertisement protocol data unit) and the AUX_ADV_IND PDU (auxiliary advertisement protocol data unit). Alternatively, the TWS device that stores the TWS mode may be either a TWS master or a TWS slave. The TWS equipment with the audio source is automatically switched to the TWS master equipment, and the TWS equipment without the audio source is automatically switched to the TWS slave equipment. The audio source includes local playing, wired playing, wireless playing, etc., for example, when the TWS device is wirelessly connected with the smart phone to play music, the TWS device is automatically switched to the TWS master device, and the TWS master device plays one channel and broadcasts the other channel to the TWS slave device for playing. Therefore, after the ACL link is established for the first time and TWS pairing is successful, the ACL link is established again with the same target second equipment and TWS pairing is performed, the data transmission process can be simplified, and the data transmission is faster and more efficient.

Fig. 12 shows a first device, configured to implement the wireless audio communication method described in fig. 1, where, as shown in fig. 12, the first device includes: the device comprises an audio input unit, an audio processing unit, a baseband data and protocol processor and a radio frequency transceiver module;

an audio input unit for acquiring an audio signal;

an audio processing unit for processing the audio signal into audio data;

the base band data and protocol processor is used for controlling the radio frequency receiving and transmitting module to broadcast and transmit audio data based on a broadcast communication link and to periodically broadcast based on an advertisement channel; the advertisement channel includes a periodic advertisement channel;

the baseband data and protocol processor is also used for negotiating with the second equipment on the periodic advertisement channel according to a pre-configured protocol to establish an asynchronous connection ACL link when the periodic broadcast is carried out; the pre-configured protocol is used for supporting bidirectional communication between the first device and the second device based on the periodic advertisement channel, and the ACL link is used for carrying out point-to-point data transmission with the second device.

Fig. 12 shows a second device, configured to implement the wireless audio communication method described in fig. 11, as shown in fig. 12, and includes: the base band data and protocol processor and the radio frequency transceiver module;

The base band data and protocol processor is used for controlling the radio frequency receiving and transmitting module to receive periodic broadcast of the first equipment based on the advertisement channel; the advertisement channel includes a periodic advertisement channel;

the baseband data and protocol processor is further configured to control the radio frequency transceiver module to receive audio data broadcast by the first device based on the broadcast communication link.

It should be noted that, because the first device and the second device (the master speaker and the slave speaker) can be switched between each other, the physical structures of the first device and the second device are substantially the same (both are shown in fig. 12). The following description will take the angle of different workflows of the first device and the second device as a starting point, and describe different functions of different modules or different functions of the same module in different workflows. As shown in fig. 12, the first device includes an audio input unit, a user interface, an audio processing unit, a baseband data and protocol processor, and a BT (Bluetooth) radio frequency transceiver module. The audio input unit obtains digital audio signals and transmits the digital audio signals to the audio processing unit, and in a specific application scenario, the audio input unit is a module for wirelessly receiving an A2DP (Advance Audio Distribution Profile, advanced audio distribution protocol) sound source. The Audio processing unit compression encodes the digital Audio signal into Audio data according to the BLE Audio protocol. The baseband data and protocol processor executes BLE Audio related BIG and BLE ACL protocols and BPA protocols and processes the Audio data into BIS PDUs suitable for transmission by the BT radio transceiver module. The BT radio frequency transceiver module is configured to transmit and receive BT radio signals or various PDUs, including transmitting and receiving PDUs related to BPA. The user interface may be a key, touch screen, wireless control interface, etc. for obtaining the Auracast and TWS mode switching instructions.

As shown in fig. 12, the second device includes a user interface, an audio output unit, an audio processing unit, a baseband data and protocol processor, and a BT radio frequency transceiver module. The baseband data and protocol processor executes BIG and BLE ACL protocols related to BLE Audio and the BPA protocol, processes BIS PDU sent by BIG/TWS main sound box received by the BLE radio frequency transceiver module, and sends the BIS PDU to the Audio processing unit; the audio processing unit is used for audio decoding, packet loss processing, equalization, sound effect and other post-processing; the audio output unit is used for converting the audio signal into a sound signal; the BT radio frequency transceiver module is used for receiving and transmitting BT radio signals or various PDUs, including transmitting and receiving PDUs related to BPA; the user interface may be a key, touch screen, wireless control interface, etc. for obtaining the Auracast and TWS mode switching instructions.

Fig. 13 shows an audio transmission system according to an embodiment of the present application, including: a first device and a second device as shown in fig. 12.

That is, the first device and the second device may constitute an audio transmission system (dual mode speaker system).

An exemplary structure of a dual mode speaker system comprising a first device and a second device is described below. As shown in fig. 13, the system is composed of two Auracast and TWS dual-mode speakers. One sound box is used as BIG/TWS master equipment (first equipment), the other sound box is used as BIG/TWS slave equipment (target second equipment), the sound box connected with the smart phone for playing A2DP audio automatically enters a BIG master equipment mode, and the sound box not connected with the smart phone for playing A2DP audio automatically enters a BIG slave equipment mode. And the BIG master equipment and the BIG slave equipment enter a TWS mode after BLE ACL connection is established through a BPA protocol, and are respectively switched into the TWS master equipment and the TWS slave equipment. In the specific application scene, the Classic BT connection, the BIG and BLE ACL connection of the TWS master device all coexist in a time division multiplexing manner.

The working process of the dual-mode sound box system structure is as follows: the dual mode speaker defaults to the Auracast mode. Any one of the dual-mode sound boxes automatically enters into a BIG main sound box mode when being connected with the smart phone through the Classic BT and the A2DP wireless sound source is opened. Other dual mode speakers that do not have an A2DP sound source turned on automatically enter BIG slave speaker mode. After the BIG main sound box receives the audio of the A2DP sound source, the audio is decoded first, the sampling rate is changed to 48kHz, and then the stereo audio downmixing (Down-Mixed) with the sampling rate of 48kHz is changed to mono audio. The BIG main sound box plays Down-Mixed mono audio through the local audio output unit, and simultaneously adopts a low-complexity communication codec (Low Complexity Communication Codec, LC 3) with a frame length of 10ms and a coding rate of 96kbps for coding, and sends the low-complexity communication codec to the BIG main sound box through a BIG link for synchronous playing from the sound box. The BIG main sound box establishes a BIG link with only one BIS, the time interval is 20ms, the main parameters of the BIG comprise 8 Sub Event numbers (NSE: number of Sub-Event), 2 Burst numbers (BN: burst Number), 4 immediate retransmission times (IRC: immediate Repetition Count), the value of the Pre-sending offset (PTO: pre-Transmission Offset) is equal to 0, and the physical layer transmission of BLE 2Mbps is adopted. After entering the TWS mode through the UI, the BIG master sound box supporting the TWS mode replaces the AUX_SYNC_IND PDU with the SYNC_SEARCH PDU on a periodic advertisement (Periodic Advertising) channel, the BIG supporting the TWS mode can send the SYNC_CONNECT_REQ PDU after receiving the SYNC_SEARCH PDU from the sound box, and the BIG master sound box collects the information (including the device name and the like in the AdvData) of the BIG slave sound box sending the SYNC_CONNECT_REQ PDU and displays the information to a user through a user interface.

And the BIG main sound box displays the collected information of the BIG slave sound box through a smart phone interface in wireless connection with the BIG main sound box. After receiving the pairing and connection instruction, the BIG main sound box sends SYNC_CONNECT_INIT PDU to the specific BIG slave sound box (target second device) on a periodic advertisement (Periodic Advertising) channel, and after receiving SYNC_CONNECT_RSP PDU replied by the specific BIG slave sound box, the user establishes BLE ACL connection with the specific BIG slave sound box, and enters TWS mode. The entry of a BIG master speaker into TWS mode may be referred to as a TWS master speaker and the entry of a BIG slave speaker into TWS mode may be referred to as a TWS slave speaker.

While the BIG main sound box is switched to the TWS main sound box, the stereo audio Down-Mixed with the sampling rate of 48kHz is not changed to mono audio, one channel (which channel is specifically selected and can be configured as a default value or can be determined by the TWS main sound box and the TWS slave sound box through connection negotiation) is selected to perform LC3 coding and is sent to the TWS slave sound box through a BIG link, and the BIG configuration parameters between the TWS main sound box and the TWS slave sound box are unchanged. And the audio of the other channel is synchronously played through the audio output unit of the TWS main sound box.

The TWS master sound box and the TWS slave sound box after pairing memorize or save the device address of the other party and save the TWS mode. After the TWS equipment with the TWS mode is restarted, the TWS mode is automatically restored, and the TWS master equipment is connected with the TWS slave equipment by directly sending the SYNC_CONNECT_INIT PDU while sending the ADV_EXT_IND PDU and the AUX_ADV_IND PDU without sending the SYNC_SEARCH PDU. TWS devices that store TWS patterns may be used as both TWS master devices and TWS slave devices. The TWS equipment connected with the smart phone and providing the audio source through the A2DP is automatically switched to the TWS master equipment, and the TWS equipment without the audio source is automatically switched to the TWS slave equipment. That is, any one of the paired TWS speakers connected to the smart phone through the A2DP audio source may become the TWS master, and the other one becomes the TWS slave.

The embodiment of the application further provides an electronic device 14, as shown in fig. 14, including: a processor 1401, a memory 1402 and a program stored in the memory 1402 and executable on the processor 1401, which when executed by the processor 1401, implement the steps of the wireless audio communication method as shown in the above-described embodiments.

The embodiment of the application further provides a computer readable storage medium, on which a computer program is stored, where the computer program when executed by a processor implements each process of the above method embodiment, and the same technical effects can be achieved, so that repetition is avoided, and no further description is given here. Wherein the computer readable storage medium is selected from Read-Only Memory (ROM), random access Memory (Random Access Memory, RAM), magnetic disk or optical disk.

It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

From the above description of the embodiments, it will be clear to those skilled in the art that the above-described embodiment method may be implemented by means of software plus a necessary general hardware platform, but of course may also be implemented by means of hardware, but in many cases the former is a preferred embodiment. Based on such understanding, the technical solution of the present application may be embodied essentially or in a part contributing to the prior art in the form of a software product stored in a storage medium (such as ROM/RAM, magnetic disk, optical disk), including several instructions for causing a terminal (which may be a mobile phone, a computer, a server, an air conditioner, or a network device, etc.) to perform the method described in the embodiments of the present application.

The embodiments of the present application have been described above with reference to the accompanying drawings, but the present application is not limited to the above-described embodiments, which are merely illustrative and not restrictive, and many forms may be made by those of ordinary skill in the art without departing from the spirit of the present application and the scope of the claims, which are also within the protection of the present application.

Claims

1. A method of wireless audio communication, the method being applied to a first device, the method comprising:

broadcast transmitting audio data based on the broadcast communication link;

2. The method according to claim 1, wherein the method further comprises: broadcasting and transmitting broadcasting configuration information on the periodic advertisement channel when the periodic broadcasting is performed; and/or the number of the groups of groups,

The time start point of each connection interval of the ACL link is the same as the time start point of the periodic broadcast.

3. The method of claim 1, wherein negotiating with a second device to establish an ACL link on the periodic advertisement channel according to a pre-configured protocol while the periodic broadcast is occurring comprises:

broadcasting and transmitting the synchronous search data packet based on a periodic advertisement channel, wherein the synchronous search data packet is used for the first equipment to search surrounding second equipment;

The target second device is one of the second devices.

4. A method according to claim 3, wherein the sync search packet carries device address information of the first device, broadcast configuration information, and indication information for indicating that ad mode AdvMode is a non-directional connectable type; and/or the number of the groups of groups,

5. The method according to claim 3 or 4, wherein the advertisement channel is configured according to bluetooth low energy BLE protocol;

6. The method of claim 1, wherein the first device is a device that supports at least a first mode, or wherein the first device is a device that supports a first mode and a second mode;

7. The method according to claim 1, wherein the method further comprises: and after the ACL link is established with the target second equipment, transmitting control information with the target second equipment based on the ACL link.

8. The method of claim 7, wherein the step of determining the position of the probe is performed,

the control information includes: audio control information associated with the audio data and/or operational status control information associated with the first device and the second device;

9. The method of claim 8, wherein in the first mode, broadcasting the transmitted audio data based on the broadcast communication link comprises: based on the broadcast communication link, broadcasting first audio data, the first audio data comprising left channel audio data and right channel audio data;

the first mode is a true wireless stereo mode.

10. The method of claim 8, wherein in the first mode, broadcasting the transmitted audio data based on the broadcast communication link comprises: based on a broadcast communication link, broadcasting and transmitting second audio data, wherein the second audio data is audio data of one channel for playing by target second equipment, and the audio data of one channel is left channel audio data or right channel audio data;

the first mode is a true wireless stereo mode.

11. A method according to claim 3, wherein said determining a target second device that is allowed to establish an ACL link after receiving said synchronous connection request packet comprises:

12. The method of claim 11, wherein the preconfigured selection mechanism comprises:

13. The method of claim 11, wherein when the first device is a device that supports a first mode and supports a second mode, the method further comprises:

14. A method according to claim 3, wherein, in the case where device information of a second device supporting the first mode is stored in the first device in advance, the negotiating with the second device to establish an ACL link on the periodic advertisement channel according to a pre-configured protocol when the periodic broadcast is performed, comprises:

the first mode is a true wireless stereo mode.

15. A method of wireless audio communication, the method being applied in a second device, the method comprising:

16. The method of claim 15, wherein the receiving the periodic broadcast of the first device based on the advertisement channel comprises: receiving broadcast configuration information broadcast by the first device on the periodic advertisement channel;

17. The method of claim 15, wherein negotiating with the first device to establish an ACL link on the periodic advertisement channel according to a pre-configured protocol upon receiving the periodic broadcast comprises:

18. The method of claim 17, wherein after receiving the sync search packet broadcast by the first device over the periodic advertisement channel, the method further comprises:

randomly generating delay with preset duration;

19. The method according to claim 15, wherein the advertisement channel is configured according to bluetooth low energy BLE protocol;

20. The method of claim 15, wherein the second device is a device that supports at least a first mode, or wherein the second device is a device that supports a first mode and a second mode;

21. The method of claim 15, wherein the method further comprises: and after the target second equipment establishes an ACL link with the first equipment, transmitting control information with the first equipment based on the ACL link.

22. The method of claim 15, wherein, in the case where device information of a first device supporting the first mode is stored in the second device in advance, the negotiating with the first device to establish an ACL link on the periodic advertisement channel according to a pre-configured protocol when receiving the periodic broadcast, comprises:

The first mode is a true wireless stereo mode.

23. A first device for implementing the wireless audio communication method of any one of claims 1 to 14, comprising: the device comprises an audio input unit, an audio processing unit, a baseband data and protocol processor and a radio frequency transceiver module;

the audio input unit is used for acquiring an audio signal;

24. A second device for implementing the wireless audio communication method of any one of claims 15 to 22, comprising: the base band data and protocol processor and the radio frequency transceiver module;

25. An audio transmission system, comprising:

the first device of claim 23;

The second device of claim 24.

26. An electronic device, comprising: a processor, a memory and a program stored on the memory and executable on the processor, which when executed by the processor, implements the steps of the wireless audio communication method of any of claims 1 to 14; alternatively, the program when executed by the processor implements the steps of a wireless audio communication method as claimed in any one of claims 15 to 22.

27. A computer readable storage medium, characterized in that the computer readable storage medium has stored thereon a computer program which, when executed by a processor, implements the steps of the wireless audio communication method according to any of claims 1 to 14; alternatively, the computer program when executed by a processor implements the steps of the wireless audio communication method of any of claims 15 to 22.