A method for adjusting an audio generation period of a bluetooth communication network

Abstract

The application discloses a kind of bluetooth communication network audio generation period adjustment methods.Wireless audio main equipment initiates isochronous transmission procedure, and wireless peripheral audio equipment selects to receive isochronous flow.Wireless audio main equipment and wireless peripheral audio equipment have audio sampling source and audio processing module with the demand of sending audio data.When the period of service data unit (SDU) generated by audio sampling source conflicts with the expected service data unit (SDU) generation period in the isochronous transmission parameters configured by audio equipment, the service data unit (SDU) generation period is compensated and adjusted by the audio processing module, and the adjusted service data unit (SDU) enters the isochronous adaptive layer (ISOAL) with a new period for segmentation.The method reduces the requirement of isochronous flow parameters for audio sampling source of the equipment, improves the versatility and bandwidth utilization of bluetooth low-power audio equipment in processing audio sampling data.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of wireless transmission, specifically the technical field of Bluetooth Low Energy Audio, and particularly relates to a Bluetooth communication network audio generation period adjustment method. BACKGROUND

[0002] The Bluetooth Low Energy Audio scheme newly added in the Bluetooth Core Specification V5.2 supports the application scenario of one wireless audio source and multiple wireless audio playback devices, such as the scenario of one audio source connecting multiple earphones and sound boxes, that is, the new application scenario of one master device and one or more peripheral devices. The basis of the scheme is that the audio source of the audio sender generates a service data unit SDU (Service Data Unit), performs data segmentation through the Isochronous Adaptation Layer ISOAL (Isochronous Adaptation Layer) to obtain a protocol data unit PDU (Protocol Data Unit), and then sends the protocol data unit PDU to the receiver by the Bluetooth baseband. The Isochronous Adaptation Layer ISOAL (Isochronous Adaptation Layer) has two data segmentation modes, that is, the framed mode and the unframed mode. The unframed mode requires that the Isochronous Event Interval (ISO_Interval) of the link layer is an integer multiple of the time interval (SDU_Interval) of the audio service data unit SDU (Service Data Unit) output by the audio source (related to the audio sampling rate), while the framed mode does not have such a requirement, but will introduce additional delay when transmitting the service data unit SDU.

[0003] The Isochronous Stream of Bluetooth Low Energy Audio includes two modes, one is the Connected Isochronous Stream CIS (Connected Isochronous Stream), compared with the classic Bluetooth audio configuration file, the master device has the right to decide the parameters of the configured Isochronous Stream, which can achieve the effect of affecting the audio quality, delay and battery life. The other is the Broadcast Isochronous Stream BIS (Broadcast Isochronous Stream), the master device controls all link configurations, and the peripheral device selects to receive part or all of the Isochronous Stream. Except for the broadcast mode BIS, any device can both generate audio data as an audio source and receive data as an audio receiver, and the initiator and the receiver can simultaneously act as an audio source device and an audio receiving device.

[0004] Since the master device is fully responsible for the configuration of isochronous stream related parameters, the selection of bandwidth utilization and data segmentation mode will be affected by the sampling rate of the master device and the isochronous interval (ISO_Interval), especially when the master device configures a bidirectional connection isochronous stream CIS, the peripheral device may not be able to meet the requirement of the segmentation mode of the master device on the audio sampling rate of the peripheral device. SUMMARY

[0005] The present application aims at the deficiencies of the prior art, and provides a method for adjusting the generation period of audio in a Bluetooth communication network.

[0006] The Bluetooth communication device according to the present application comprises a wireless audio master device and one or more wireless peripheral audio devices. The wireless audio master device initiates an isochronous transmission process, and the wireless peripheral audio device selects to receive part or all of the isochronous stream. The wireless audio master device and the wireless audio peripheral device interact with each other bidirectionally or transmit data unidirectionally through Bluetooth isochronous communication.

[0007] In the wireless audio master device and the wireless peripheral audio device, the device that has a demand for transmitting audio data has an audio sampling source and an audio processing module. The audio sampling source periodically generates audio service data units SDU at a certain sampling rate. When the wireless audio master device configures isochronous transmission parameters, it selects a data segmentation mode according to the bandwidth occupation demand. When the wireless audio peripheral device accepts a connection isochronous stream CIS configuration, it can configure its own audio source parameters according to the connection parameter requirement, establish a connection isochronous stream CIS, and can interact with the wireless audio master device for audio data. When accepting a broadcast isochronous stream BIS, the wireless audio peripheral device selects to receive part or all of the isochronous stream data according to the demand.

[0008] The wireless audio master device and the wireless peripheral audio device both have the basic characteristics of Bluetooth Core Specification V5.2 and above version of Bluetooth Low Energy Audio, and the requirement of the device audio source on the isochronous transmission parameters is reduced through period adjustment. The isochronous adaptation layer ISOAL in Bluetooth Core Specification V5.2 can segment the service data units SDU to obtain protocol data units PDU.

[0009] The audio processing module has a storage FIFO module and a timing processing module. The storage FIFO module has sufficient memory space to store data from the audio sampling source. The timing processing module can set a period to process the data of the storage FIFO module, i.e., the service data units SDU of the storage FIFO module are continuously taken out at a set period and transmitted to the isochronous adaptation layer ISOAL. The audio processing module can adjust the generation period of the service data units SDU by using the timing module and the storage FIFO module, so as to convert the framed and unframed two data segmentation modes according to the demand.

[0010] The specific period adjustment method is:

[0011] The wireless audio master device utilizes the audio processing module to give the configuration isochronous transmission parameter information optimal to the bandwidth occupation of itself according to the bandwidth occupation of itself and the audio sampling frequency configuration when configuring the isochronous transmission parameter.

[0012] The wireless audio peripheral device utilizes the audio processing module to solve the conflict between the parameter provided by the wireless audio master device and the audio sampling rate of itself when configuring the isochronous stream CIS connection according to the isochronous transmission parameter information provided by the wireless audio master device.

[0013] The specific audio processing flow of the device audio processing module of the sending terminal device: in the Bluetooth low power consumption communication, the basic data unit sent is a protocol data unit PDU, and the Bluetooth low power consumption audio service data unit SDU needs to be segmented to obtain the protocol data unit PDU; in the Bluetooth communication network audio generation cycle adjustment system, the audio device sampling source generates the audio service data unit SDU, which is first sent to the audio processing module, and then sent to the isochronous adaptation layer ISOAL to segment the service data unit SDU to obtain the protocol data unit PDU.

[0014] The period of the audio data generated by the audio sampling source is related to the audio sampling frequency, and when the period of the service data unit SDU generated by the audio sampling source conflicts with the expected service data unit SDU generation period in the audio device configuration isochronous transmission parameter, the storage FIFO module in the audio processing module is used to compensate and adjust the service data unit SDU generation period according to the time difference relationship; the compensated service data unit SDU enters the isochronous adaptation layer ISOAL for segmentation with a new period.

[0015] Through the method of the application, whether the wireless audio master device or the wireless audio peripheral device, the problem caused by the conflict between the period of the service data unit SDU generated by the audio sampling source and the expected service data unit SDU generation period in the audio device configuration isochronous transmission parameter can be solved, the restriction caused by the relationship between the audio sampling rate and the isochronous event interval is reduced, thereby reducing the requirement of the device audio sampling source on the isochronous stream parameter, improving the universality of the Bluetooth low power consumption audio device in processing the audio sampling data and the bandwidth utilization rate, and reducing certain delay. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 It is a schematic diagram of the audio processing module of the application;

[0017] Figure 2 It is a schematic diagram of the isochronous stream CIS establishment flow of an embodiment of the application. DETAILED DESCRIPTION

[0018] A Bluetooth communication network audio generation period adjustment method, as shown in Figure 1 The Bluetooth communication device involved includes a wireless audio master device (such as a smart phone, a tablet computer, a notebook computer, etc.) and one or more wireless peripheral audio devices (such as earphones, a sound box, etc.). The wireless audio master device initiates an isochronous transmission process, and the wireless peripheral audio device selects to receive part or all of the isochronous stream. The wireless audio master device and the wireless audio peripheral device interact bidirectionally or transmit unidirectionally through Bluetooth isochronous communication.

[0019] The wireless audio master device and the wireless peripheral audio device have an audio sampling source and an audio processing module with a demand for sending audio data. When the wireless audio master device configures isochronous transmission parameters, it does not need to consider the audio sampling information of the wireless audio peripheral device, can reduce the influence of its own audio sampling rate, and can select a data segmentation mode according to the bandwidth occupation demand. When the wireless audio peripheral device accepts the connection isochronous stream CIS configuration, it can reduce the influence caused by the conflict between the connection parameters and its own audio sampling rate, configure its own audio source parameters according to the connection parameter requirements, successfully establish a connection isochronous stream CIS, and can interact with the wireless audio master device for audio data; when accepting the broadcast isochronous stream BIS, the wireless audio peripheral device selects to receive part or all of the isochronous stream data according to the demand.

[0020] The wireless audio master device and the wireless peripheral audio device both have the basic characteristics of Bluetooth Core Specification V5.2 and above version Bluetooth Low Energy Audio, and through period adjustment, the requirements of the device audio source on the isochronous transmission parameters are reduced, the versatility and bandwidth utilization of the device are increased, and certain delay is reduced. The isochronous adaptation layer ISOAL in Bluetooth Core Specification V5.2 can segment the service data unit SDU to obtain a protocol data unit PDU.

[0021] The audio sampling source periodically generates audio service data units SDU at a certain sampling rate.

[0022] The audio processing module has a storage FIFO module and a timing processing module. The storage FIFO module has sufficient memory space to store data from the audio sampling source. The timing processing module can set a period to process the data of the storage FIFO module, that is, continuously take out the service data unit SDU of the storage FIFO module at a set period and transmit it to the isochronous adaptation layer ISOAL.

[0023] The audio processing module can adjust the generation period of the service data unit SDU by using the timing module and the storage FIFO module, so as to convert the framing and non-framing two data segmentation modes according to the demand.

[0024] The specific period adjustment method is:

[0025] When the period of service data unit SDU generated by the audio sampling source conflicts with the expected service data unit SDU generation period in the transmission parameters of the audio device configuration, the elements stored in the storage FIFO module in the audio processing module are temporarily stored, and then the period of taking out the elements stored in the storage FIFO module in the timing processing module is set according to the time difference relationship between the period of service data unit SDU generated by the audio sampling source and the expected service data unit SDU generation period in the transmission parameters of the audio device configuration, so as to achieve the effect of adjusting the service data unit SDU generation period. The adjusted service data unit SDU enters the isochronous adaptation layer ISOAL in a new period and is segmented in a specified segmentation manner.

[0026] The specific audio processing flow of the device audio processing module of the sending end device: in Bluetooth low-power communication, the basic data unit sent is a protocol data unit PDU, and the Bluetooth low-power audio service data unit SDU needs to be segmented in a specified segmentation manner to obtain the protocol data unit PDU. In the present application, after the audio service data unit SDU is generated by the audio device sampling source, it is first sent to the audio processing module, and then sent to the isochronous adaptation layer ISOAL to segment the service data unit SDU in a specified segmentation manner to obtain the protocol data unit PDU.

[0027] The period of the audio service data unit SDU generated by the audio sampling source is related to the audio sampling frequency, and the non-framed data segmentation manner requires that the isochronous event interval (ISO_Interval) of the link layer is an integer multiple of the time interval (SDU_Interval) of the audio service data unit SDU output by the audio sampling source. When configuring the isochronous transmission parameters, the wireless audio master device adjusts the service data unit SDU generation period by using the audio processing module, which can reduce the influence of the audio sampling frequency, and thus according to the bandwidth occupation and the audio sampling frequency, the isochronous transmission parameter information configuration optimal to the bandwidth occupation of the wireless audio master device is given. The isochronous transmission parameter information includes the isochronous event interval, the time interval of the audio service data unit SDU output by the audio source, and the segmentation manner.

[0028] When the wireless audio peripheral device connects the isochronous stream CIS connection configuration according to the isochronous transmission parameter information provided by the wireless audio master device, the audio processing module is used to adjust the service data unit SDU generation period, so as to solve the conflict between the parameters provided by the wireless audio master device and the audio sampling rate of the wireless audio peripheral device.

[0029] When the wireless audio master device configures the isochronous stream parameters, it wants to interact with the wireless audio peripheral device to transmit audio data, and the influence of the audio sampling frequency on it needs to be considered, and the audio processing module can minimize the influence. That is, when the wireless audio master device and the wireless audio peripheral device are connected, the audio processing module is used to adjust the service data unit SDU generation period, which can solve the problem that the service data unit SDU generation period of the wireless audio master device cannot meet the requirements of the optimal parameter specified service data unit SDU segmentation mode. Therefore, the wireless audio master device does not need to consider configuring the isochronous stream parameters according to the audio sampling information of the wireless audio peripheral device, and when the service data unit SDU generation period of the wireless audio peripheral device cannot meet the requirements of the service data unit SDU generation period or the segmentation mode specified by the wireless audio master device, only the audio processing module is used to adjust the service data unit SDU generation period, and the wireless audio peripheral device can meet the requirements of the isochronous stream CIS connection parameters. Similarly, when the wireless audio master device uses broadcast isochronous stream BIS to send data, the audio processing module is used to adjust the service data unit SDU generation period, which can solve the problem that the service data unit SDU generation period of the wireless audio master device cannot meet the requirements of the optimal parameter specified service data unit SDU segmentation mode.

[0030] Whether it is a wireless audio master device or a wireless audio peripheral device, this method can reduce the requirements of the device audio source on the isochronous stream parameters, increase the versatility and bandwidth utilization of the device, and reduce certain delay.

[0031] In order to more clearly describe the features of the present application, the connection isochronous stream CIS connection process of the wireless audio master device and the wireless audio peripheral device establishing bidirectional communication is further described as follows: Figure 2 The steps include:

[0032] 1. The wireless audio master device and the wireless audio peripheral device establish an asynchronous connection link ACL (Asynchronous Connection-Oriented Link);

[0033] 2. The wireless audio master device and the wireless audio peripheral device establish a connection isochronous stream CIS:

[0034] a.The wireless audio master device configures the isochronous stream connection parameters optimal to itself by using the audio processing module, and then initiates the connection isochronous stream (CIS) connection. For example, when the optimal connection isochronous stream (CIS) connection parameters of the wireless audio master device are isochronous object interval (ISO_Interval), and the interval at which the audio sample source generates service data units (SDUs) is SDU_Interval, the condition that ISO_Interval is equal to or is an integer multiple of SDU_Interval is not met. At this time, the unframed segmentation mode is designated to be used, and the timing processing module in the audio processing module can be used to set the timing processing period to SDU_Interval1. The processing period SDU_Interval1 meets the condition ISO_Interval=N*SDU_Interval1 (N is an integer greater than or equal to 1), that is, the unframed segmentation mode requirement is met. At this time, the generation interval parameter of the SDU from the wireless audio master device to the wireless audio peripheral device in the CIS_REQ is set to SDU_Interval1. In the subsequent interaction process, when SDU_Interval1 is less than SDU_Interval, the storage FIFO will be empty. The ISOAL characteristic is used to perform packet filling by using the empty payload. When SDU_Interval1>SDU_Interval, if the unframed segmentation mode is used, the buffer in the storage FIFO module in the audio processing module will continue to increase. Therefore, the timing processing period SDU_Interval1 is set to meet the condition SDU_Interval1<SDU_Interval, so that it can be ensured that the buffer in the storage FIFO module will not overflow.

[0035] b. When the wireless audio peripheral device performs the isochronous stream CIS connection configuration according to the parameters provided by the wireless audio master device, if the parameters provided by the wireless audio master device conflict with the audio sampling rate of the wireless audio peripheral device, or the wireless audio peripheral device cannot meet the requirement of the specified service data unit SDU segmentation mode, the wireless audio peripheral device adjusts the service data unit SDU generation period by using the audio processing module, so as to meet the parameter requirement of the wireless audio master device, and replies to the isochronous stream CIS connection request. For example, the generation interval parameter of the service data unit SDU from the wireless audio peripheral device to the wireless audio master device in the CIS_REQ is SDU_Interval, and the non-framing Unframed segmentation mode is specified. However, the period of the service data unit SDU generated by the audio sampling of the wireless audio peripheral device is SDU_Interval2, and SDU_Interval2≠SDU_Interval, which cannot meet the requirement of the non-framing Unframed segmentation mode. The audio processing module can be used to set the timing period as SDU_Interval3, and SDU_Interval3=SDU_Interval*N (N is an integer greater than or equal to 1), so as to meet the requirement. In the subsequent interaction process, when SDU_Interval3 is less than SDU_Interval2, the storage FIFO is empty. By using the characteristics of the ISOAL, the empty payload is used for packet supplement. When SDU_Interval3>SDU_Interval2, the cache in the storage FIFO module in the audio processing module is continuously increased. Therefore, the timing processing period SDU_Interval3 set by the wireless audio peripheral device meets the requirement of SDU_Interval3<SDU_Interval2, so as to ensure that the cache in the storage FIFO module is not overflowed.

[0036] SDU_Interval3 (N is an integer greater than or equal to 1), so as to meet the requirement. In the subsequent interaction process, when SDU_Interval3 is less than SDU_Interval2, the storage FIFO is empty. By using the characteristics of the ISOAL, the empty payload is used for packet supplement. When SDU_Interval3>SDU_Interval2, the cache in the storage FIFO module in the audio processing module is continuously increased. Therefore, the timing processing period SDU_Interval3 set by the wireless audio peripheral device meets the requirement of SDU_Interval3<SDU_Interval2, so as to ensure that the cache in the storage FIFO module is not overflowed.

[0037] 3. Isochronous stream CIS data interaction: After the wireless audio master device and the wireless audio peripheral device generate audio source data, the data enters the storage FIFO module in the audio processing module. The timing processing module in the audio processing module starts to work according to the set period, and finally obtains the service data unit SDU meeting the time period requirement in the isochronous stream CIS connection parameters. After the service data unit SDU is segmented by the isochronous adaptation layer ISOAL, the protocol data unit PDU is obtained, and the isochronous stream data interaction is started.

Claims

1. A method for adjusting an audio generation period of a Bluetooth communication network, involving a Bluetooth communication device comprising a wireless audio master device and one or more wireless peripheral audio devices. The wireless audio master device initiates an isochronous transmission process, and the wireless peripheral audio device selects to receive part or all of the isochronous stream; the wireless audio master device and the wireless audio peripheral device interact with each other or transmit in one direction through Bluetooth isochronous communication; characterized in that: The wireless audio master device and the wireless peripheral audio device have an audio sampling source and an audio processing module in the device that needs to send audio data; the audio sampling source periodically generates audio service data units (SDUs); The audio processing module has a storage FIFO module and a timing processing module; the storage FIFO module has sufficient memory space to store data from the audio sampling source; the timing processing module can set a period to process the data in the storage FIFO module, that is, the service data units (SDUs) in the storage FIFO module are continuously taken out at a set period and transmitted to the isochronous adaptation layer (ISOAL); the audio processing module can use the timing module and the storage FIFO module to adjust the generation period of the service data units (SDUs), thereby converting the two data segmentation modes of framing and non-framing as needed; The specific period adjustment method is as follows: When configuring isochronous transmission parameters, the wireless audio master device uses the audio processing module to give the optimal configuration isochronous transmission parameter information relative to its own bandwidth occupation based on its own bandwidth occupation and audio sampling frequency configuration, without considering configuring isochronous stream parameters based on the audio sampling information of the wireless audio peripheral device, and selecting a data segmentation mode according to bandwidth occupation requirements; When the wireless audio peripheral device connects to the isochronous stream (CIS) connection configuration based on the isochronous transmission parameter information provided by the wireless audio master device, the audio processing module is used to solve the conflict between the parameters provided by the wireless audio master device and the audio sampling rate of the wireless audio peripheral device; when the wireless audio peripheral device accepts the connection isochronous stream (CIS) configuration, if the parameters provided by the wireless audio master device conflict with the audio sampling rate of the wireless audio peripheral device, it cannot meet the requirements of the specified service data unit (SDU) segmentation mode, the audio processing module is used to adjust the service data unit (SDU) generation period of the wireless audio peripheral device to meet the parameter requirements of the wireless audio master device, configure the audio source parameters of the wireless audio peripheral device according to the connection parameter requirements, establish a connection isochronous stream (CIS), and enable the wireless audio peripheral device to interact with the wireless audio master device; when accepting the broadcast isochronous stream (BIS), the audio processing module is used to adjust the service data unit (SDU) generation period to solve the problem that the service data unit (SDU) generation period of the wireless audio peripheral device cannot meet the requirements of the optimal parameter specified service data unit (SDU) segmentation mode, and the wireless audio peripheral device selects to receive part or all of the isochronous stream data according to requirements. The specific audio processing flow of the device audio processing module of the sending end device: in the Bluetooth low energy communication, the basic data unit sent is a protocol data unit PDU, and the Bluetooth low energy audio service data unit SDU needs to be segmented to obtain the protocol data unit PDU; in the Bluetooth communication network audio generation cycle adjustment system, after the audio service data unit SDU generated by the audio device sampling source passes through the audio processing module, it is sent to the isochronous adaptation layer ISOAL to segment the service data unit SDU to obtain the protocol data unit PDU; The period of audio data generated by the audio sampling source is related to the audio sampling frequency, when the period of the service data unit SDU generated by the audio sampling source conflicts with the expected service data unit SDU generation period in the audio device configuration isochronous transmission parameter, the service data unit SDU generation period is compensated and adjusted according to the time difference relationship through the storage FIFO module in the audio processing module; the compensated service data unit SDU enters the isochronous adaptation layer ISOAL for segmentation with a new period.

2. The method of claim 1, wherein: the audio generation period is adjusted based on a number of audio frames received from the first Bluetooth device. The wireless audio master device and the wireless peripheral audio device can both reduce the requirement of the device audio source on the isochronous transmission parameter through cycle adjustment, and have the basic characteristics of the Bluetooth core specification V5.2 and above version Bluetooth low energy audio; after the audio service data unit SDU generated by the audio device sampling source passes through the audio processing module, it is sent to the isochronous adaptation layer ISOAL, and the isochronous adaptation layer ISOAL in the Bluetooth core specification V5.2 can segment the service data unit SDU to obtain the protocol data unit PDU. ​

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