SYSTEM AND METHOD FOR MANAGING AUDIO QUALITY IN A LOW ENERGY AUDIO BROADCAST SCENARIO

A method for managing the audio quality in an audio broadcast scenario performed by a source device is provided. The method includes reserving a receiver (Rx) slot in the source device to receive link quality feedback packets from one or more sink devices and transmitting Rx slot information to the one or more sink devices in a control subevent of a broadcast isochronous channels (BIS) event. The method further includes receiving the link quality feedback data packets from the one or more sink devices in the reserved Rx slot and determining a quality of a broadcast link between the source device and the one or more sink devices by scanning the received link quality feedback data packets and thereafter based on a result of the determination, optimizing at least one of a plurality of low energy (LE) isochronous parameters to manage audio quality and reliability of the broadcast link.

BACKGROUND

The disclosure relates to the field of low energy audio. More particularly, the disclosure relates to a system and method for managing audio quality in a low energy audio broadcast scenario.

2. Description of Related Art

The Bluetooth® Core Specification defined by the Bluetooth Special Interest Group (SIG) introduced the low-power audio transmission over Bluetooth called low energy (LE) audio. LE audio operates on the Bluetooth LE standard. Bluetooth SIG introduced a new feature in the latest specification version 5.2 called Isochronous Channels (ISOC). ISOC lays the foundation for the implementation of the LE Audio.

Isochronous channels are used to transfer time bounded data between devices. Multiple sink devices, receiving data from the same source, will render it at the same time. Isochronous channels may be connection-oriented or connectionless (broadcast). Broadcast Audio allows for one or multiple audio streams to be broadcast to an unlimited number of devices. It enables applications like Personal Audio Sharing where a user can share their audio stream, for example from a phone or tablet, with other user's headphones in the vicinity. Bluetooth LE Audio Isochronous channels are of two types (a) Unicast Connection Oriented Isochronous Channels (CIS Channels) and (b) Broadcast Isochronous Channels (BIS Channels).

The CIS channels are logical transport channels that enable connected devices to transfer isochronous data unidirectionally and bidirectionally. The isochronous data can be transferred either in a LE-Stream (LE-S) or LE-Frame (LE-F) logical link by using the CIS based logical transport. It can be also called a reliable transmission of isochronous data because the master device can keep retransmitting the isochronous data packet until it receives an acknowledgment from the slave device. Further, since isochronous channels are used to transfer time bounded data, the isochronous data packet will be flushed after a flush timeout. This number can be set dynamically based on link quality/RF interference (Max 255 CIS events).

The BIS channels are logical transport channels that enable a broadcasting source device to transfer isochronous data (framed or unframed). The BIS channels support variable-size packets and the transmission of one or more packets in each isochronous event, enabling LE audio to support a range of data rates. The data traffic is unidirectional from the broadcasting source device. Therefore, no acknowledgment protocol exists, making broadcast isochronous traffic unreliable. To improve the reliability of the packet delivery, the isochronous data packets can be unconditionally re-transmitted determined by the parameter: IRC (“Immediate Repetition Count”. This number is set once in the range 1 to a Number of Subevents ((NSE) per BIS event/a number of payloads (Burst Number (BN)) available per BIS event. There is no link quality indicator available to dynamically modify this value.

FIG.1Aof the drawings illustrates a LE audio system depicting a broadcast source101as a source device, broadcast sinks105A and105B as one or more sink devices, and broadcast assistants103A,103B as assistants to the one or more sink devices, in accordance with an existing state of the art. There may be many sink devices that can be synchronized to the source device. When a user carrying the sink devices moves out of range of the broadcast source device, the user hears audio choppiness. Also, since Bluetooth operates in an unlicensed ISM band at 2.4 GHz, it may face interference from other wireless technologies (WLAN, DECT, etc.), so there arises a need for updating frequency channels to be used at the source device side. Further, unlike connection oriented channels, Broadcast Channels are unreliable as there is no acknowledgment mechanism. Though Bluetooth SIG specification adds limited retransmission ability in the Broadcast Source device, it is generally fixed and there is no awareness in Broadcast Source of the RF environment. Also, since the limited retransmission is fixed, the isochronous data packets may be retransmitted unnecessarily and may cause more battery consumption at the Broadcast Source device side.

Therefore, there lies a need for a method and system that can improve audio quality in the LE audio broadcast scenario.

SUMMARY

Aspects of the disclosure are to address at least the above-mentioned problems and/or disadvantages and to provide at least the advantages described below. Accordingly, an aspect of the disclosure is to provide a system and method for managing the audio quality in the LE audio broadcast scenario by a source device.

In accordance with an aspect of the disclosure, a method for managing the audio quality in the audio broadcast scenario performed by the source device is provided. The method includes reserving a receiver (Rx) slot in the source device to receive link quality feedback data packets from one or more sink devices. The reserved Rx slot includes Rx slot information. The method further includes transmitting the Rx slot information to the one or more sink devices in a control subevent of a Broadcast Isochronous Stream (BIS) event and receiving the link quality feedback data packets from the one or more sink devices in the reserved Rx slot in response to the transmitted Rx slot information. The method further includes determining a quality of a broadcast link between the source device and the one or more sink devices by scanning the received link quality feedback data packets and thereafter based on a result of the determination, optimizing at least one of a plurality of LE isochronous parameters to manage the quality of the broadcast link.

In accordance with another aspect of the disclosure, a system for managing the audio quality in the audio broadcast scenario is provided. The system includes a source device that includes at least one controller and one or more sink devices. The at least one controller is configured to reserve a receiver (Rx) slot in the source device to receive link quality feedback data packets from the one or more sink devices. The reserved Rx slot includes Rx slot information. The at least one controller is further configured to transmit the Rx slot information to the one or more sink devices in a control subevent of a Broadcast Isochronous Stream (BIS) event and receive the link quality feedback data packets from the one or more sink devices in the reserved Rx slot in response to the transmitted x slot information. The at least one controller is further configured to determine a quality of a broadcast link between the source device and the one or more sink devices by scanning the received link quality feedback data packet, and thereafter based on the result of the determination, optimize at least one of a plurality of LE isochronous parameters to manage the quality of the broadcast link.

In accordance with another aspect of the disclosure, a system for managing the audio quality in the audio broadcast scenario is provided. The system includes a source device, one or more sink devices, and a plurality of broadcast assistant devices each including at least one controller. The plurality of broadcast assistant devices includes a primary broadcast assistant device. The one or more sink devices are configured to transmit link quality feedback data packets to the plurality of broadcast assistant devices. Further, the at least one controller of each of the plurality of broadcast assistant devices is configured to form a family group of the plurality of broadcast assistant devices using a user account registered on a corresponding broadcast assistant device of the plurality of broadcast assistant devices. Further, the at least one controller of the primary broadcast assistant device is configured to scan the link quality feedback data packets to determine a quality of a broadcast link between the source device and the one or more sink devices, establish a LE-based connection with the source device, and then transmit a result of the determination of the quality of the broadcast link to the source device.

DETAILED DESCRIPTION

The term “some” as used herein is defined as one, or more than one, or all.” Accordingly, the terms “one,” “more than one,” or “more than one,” or “all” would all fall under the definition of “some.” The term “some embodiments” may refer to one embodiment or several embodiments or all embodiments. Accordingly, the term “some embodiments” is defined as meaning “one embodiment, or more than one embodiment, or all embodiments.”

The terminology and structure employed herein are for describing, teaching, and illuminating some embodiments and their specific features and elements and do not limit, restrict, or reduce the spirit and scope of the claims or their equivalents.

More specifically, any terms used herein such as but not limited to “includes,” “including,” “comprises,” “has,” “have” and grammatical variants thereof do NOT specify an exact limitation or restriction and certainly do NOT exclude the possible addition of one or more features or elements, unless otherwise stated, and must NOT be taken to exclude the possible removal of one or more of the listed features and elements, unless otherwise stated with the limiting language “MUST comprise” or “NEEDS TO include.”

Whether or not a certain feature or element was limited to being used only once, either way, it may still be referred to as “one or more features” or “one or more elements” or “at least one feature” or “at least one element.” Furthermore, the use of the terms “one or more” or “at least one” feature or element do NOT preclude there being none of that feature or element unless otherwise specified by limiting language such as “there NEEDS to be one or more . . . ” or “one or more element is required.”

The term “module” and “engine” used in the document may imply a unit including, for example, one of hardware, software, and firmware or a combination of two or more of them. The “module” and “engine” may be interchangeably used with a term such as logic, a logical block, a component, a circuit, and the like. The “module” and “engine” may be a minimum system component for performing one or more functions or may be a part thereof. For example, the “module” and “engine” of the disclosure may include at least one of an Application-Specific Integrated Circuit (ASIC) chip, a Field-Programmable Gate Arrays (FPGAs), a programmable-logic device, or a combination of programmable-logic devices which are known or will be developed, and which perform certain operations.

Unless otherwise defined, all terms, and especially any technical and/or scientific terms, used herein may be taken to have the same meaning as commonly understood by one having ordinary skill in the art.

Embodiments of the disclosure will be described below in detail with reference to the accompanying drawings.

FIG.1Bis a block diagram depicting a hardware configuration of the source device, according to an embodiment of the disclosure.

The source device corresponds to one of a television, an audio reproduction system, or a portable electronic device that can transmit audio packets to one or more sink devices. Here, the one or more sink devices may correspond to one of but is not limited to, wireless earbuds, TWS, Bluetooth earphones, or a wireless headset. The one or more sink devices may correspond to any earpiece device configured to reproduce audio.

The hardware configuration of the source device includes a transmitter (Tx) module107, a receiver (Rx) Module109, and a processing engine111such as a central processing unit (CPU), a processing circuitry, one or more controllers, and the like, and that is configured to control overall operations performed by the source device. The processing engine111is configured to reserve a receiver (Rx) slot in the source device to receive link quality feedback data packets from one or more sink devices. The reserved Rx slot includes Rx slot information. The processing engine111is configured to transmit the Rx slot information to the one or more sink devices in a control subevent of a Broadcast Isochronous Stream (BIS) event using the Tx module107. The processing engine111is further configured to receive the link quality feedback data packets from the one or more sink devices in the reserved Rx slot in response to the transmitted Rx slot information. A more detailed description of the operations and functionalities of the processing engine is described below with reference toFIGS.3,4,5A,5B, and6of the drawings.

FIG.2is a block diagram illustrating a system architecture200of an audio system for managing the audio quality in the audio broadcast scenario, according to an embodiment of the disclosure.

The audio system includes an application layer201, a framework layer203to provide access to low-level audio components, a Bluetooth (BT) Host Stack205, a BT controller209, and a Vendor Specific Event (VSE)207which is received by the BT Host Stack205from the BT controller209. The BT controller209includes a Host Controller Interface (HCI)211, Isochronous Adaptation Layer (ISOAL)213, and a link layer215. The BT Host Stack205includes Bluetooth Low Energy (BLE) Audio Protocols205A, HCI ISO Control205C, BT Audio HAL205B, LE Audio Codec205D, and HCI ISO Data205E.

The framework layer203includes BLE Audio Framework203A, Audio Primary audio hardware abstraction layer (HAL)203B, Audio Flinger203C, and an Audio Policy Manager203D. The BLE Audio Framework203A is responsible to interact with the BT Audio HAL205B to send Link Quality Information to the BT Audio HAL205B. Additionally, the Link Quality-quality of service (QOS) Mapping table can be defined and passed to the BT Audio HAL205B. The Audio Primary HAL203B defines a basic interface layer between the audio related drivers for the Audio Policy Manager203D. Where the Audio Policy Manager203D defines one or more APIs to access and control underlying audio system subcomponents. The Audio Flinger203C corresponds to a sound server implementation. The Audio Flinger203C runs within a media server process.

The HCI211is a standardized Bluetooth interface for sending commands, receiving events, and for sending and receiving data. It is typically realized as a serial interface, using either RS232 or USB communication devices. As the name implies, the HCI is used to bridge the BT Host Stack205and the controller devices such as the BT controller209. commands and events can either be specified or can be vendor specific for extensibility.

The HCI ISO Control205C and the HCI211create a new HCI vendor specific event to inform the BT Host Stack205when there is a change in audio link state transition. Also, a new Link Quality Profile/Service can be defined using the BLE Audio Protocols205A of the BT Host Stack205to interact with a primary broadcast assistant device to receive link quality notifications. The BLE Audio Protocols205A is configured to enable/disable the broadcast quality improvement feature. The user of the audio system has the option to enable/disable the feature. When the broadcast quality improvement feature is enabled, the BT controller209will enter mode to enable receiving audio Link quality feedback data packets and sends to the host. When the broadcast quality improvement feature is disabled, the BT controller209is stopped to receive the audio Link quality feedback data packets and sending the link information to the host. Additionally, when the broadcast quality improvement feature is enabled, a timer can also be set to inform the BT controller209how often it needs to evaluate link quality.

The application layer201includes one or more music applications201A and BT setting201B. The BT setting201B includes user interface options to control the enabling operation of the Broadcast Quality Improvement feature. Additionally, the BT setting201B may include a selection option to select Primary Broadcast Assistant among the family member list of audio devices.

The BT Audio HAL205B of the BT Host Stack205is configured to receive link quality feedback information and configure LE audio codec configuration to meet the audio quality requirements such as but not limited to the sampling frequency, frame duration, Octets per codec frame, etc. The LE Audio Codec205D may correspond to one of a Low Complexity Communication Codec (LC3). This codec is configured to compress the audio data packets for transmission over the air.

The BT controller209may act as the processing engine111ofFIGS.1A and1Band controls the overall operation of the audio system in combination with the subcomponents ofFIGS.1A,1B, and2.

The ISOAL213enables the lower and upper layers of the stacks as shown inFIG.2to work together. The ISOAL213provides segmentation, fragmentation, reassembly and recombination services for conversion of service data units (SDUs) from the upper layer to Protocol Data Units (PDUs) of the Link Layer and vice versa. The ISOAL213accepts or generates SDUs, each with a length up to the maximum length (Max_SDU), at a rate that is supported by the BT controller209. SDUs are transferred to and from the upper layer using either HCI ISO Data205E or over an implementation-specific transport.

The Link layer215is responsible for reserving the Rx Slot in the source device for receiving link quality feedback data packets under the control of the BT controller209. The Link layer215is also responsible to control QoS Parameters for Broadcast (BIS).

FIG.3illustrates a flowchart of method operations for managing audio quality in the LE audio broadcast scenario, according to an embodiment of the disclosure.FIG.3depicts a method300that is executed by the BT controller209ofFIG.2or processing engine111ofFIG.1Bof the drawings.

Referring toFIG.3, the method300at operation301, comprises reserving a receiver (Rx) slot in the source device to receive link quality feedback data packets from the one or more sink devices. As an example, the BT controller209reserves the Rx Slot in the source device using the link layer215for receiving link quality feedback data packets from the one or more sink devices. The reserved Rx slot includes Rx slot information. The flow of the method300now proceeds to operation303).

At operation303, the method300comprises transmitting the Rx slot information to the one or more sink devices in a control subevent of a Broadcast Isochronous Stream (BIS) event. As an example, the BT controller209periodically transmits the Rx slot information (to the one or more sink devices in the control subevent of the BIS event via the Tx module107. The periodicity (interval) can vary based on the link quality feedback data packets from the one or more sink devices. The Rx slot information indicates timing information about when the source device will open its Rx Slot for listening to the link quality feedback data packets from the one or more sink devices. An example of the control subevent of the BIS event is illustrated inFIG.4of the drawings for ease of explanation.

FIG.4illustrates an example time reference graph indicating control events and subevent of a Broadcast Isochronous Group (BIG) event and a BIS event, according to an embodiment of the disclosure.

Referring toFIG.4, a BIG event includes two or more BISs having the same ISO interval and that is expected to have a time relationship at the application layer201, or of a single BIS. For each BIS within a BIG event, a schedule of transmission time slots, i.e., events and subevents are present. Each BIS event starts at a BIS anchor point and ends after its last subevent and each BIG event starts at a BIG anchor point401and ends after the control subevent403. A BIS subevent enables an isochronous broadcaster to transmit a BIS Protocol Data Unit (PDU) and enables the Rx module109to receive it. A format of the payload of a BIG Control PDU is shown on the right-hand side ofFIG.4. The Opcode field of the payload specifies different types of BIG control PDUs. The Opcode field also specifies the CtrData field in the payload of BIG control PDU. For a given Opcode, the length of the CtrData field is fixed. The Instant field of the CtrData shall be set to the value of bigEventCounter15-0 which is used by Synchronized receivers to track the Rx event slot. The Rx slot will open in the event which appears after ReceiveEventCount events after the Instant event.

FIG.5Aillustrates a time reference graph of the BIG receive event, according to an embodiment of the disclosure.

Referring toFIG.5A, BIG_RX_SLOT_IND indicates a BIG Control PDU received in the control subevent of BIG Event x, the BIG instant event indicates an instant value of the BIG_RX_SLOT_IND, and the BIG receive event is a combination of the BIG instant event and the ReceiveEventCount value of the BIG_RX_SLOT_IND. The portion that is highlighted in black color indicates the last subevent of the BIG receive event that is used as the Rx slot.

Further, in accordance with some embodiment of the disclosure, the reserved Rx slot includes a plurality of sub-slots to receive the link quality feedback data packets from the one or more sink devices. The number of sub-slots and the duration of each sub-slot are determined by the source device. This information is shared with all the sink devices in the BIG_RX_SLOT_IND control PDU. Further, to avoid collision, the source device may use a different RF frequency channel for each sub-slot.

FIG.5Billustrates a time reference graph where the last subevent of the BIG receive event is divided into a plurality of time slots to receive the link quality feedback data packets from the one or more sink devices according to an embodiment of the disclosure. The flow of the method300now proceeds to operation305.

At the operation305, subsequent to the transmission of the Rx slot information to the one or more sink devices, the method300comprises receiving the link quality feedback data packets from the one or more sink devices in the reserved Rx slot. As an example, the source device receives the link quality feedback data packets from the one or more sink devices in the reserved Rx at the timing indicated by the timing information in the transmitted Rx slot information. The link quality feedback data packets include feedback information regarding the quality of a broadcast link between the source device and the one or more sink devices. The flow of the method300now proceeds to operation307.

At the operation307, after the reception of the link quality feedback data packets by the source device, the method300comprises determining a quality of a broadcast link between the source device and the one or more sink devices by scanning the received link quality feedback data packets. A result of the determination of the quality of the broadcast link is an indicator of a Tx quality of audio data packets to the one or more sink devices. As an example, the BT controller209is configured to scan the received link quality feedback data packets and fetch feedback information related to a Tx quality of audio data packets from the source device to the sink devices based on the scanning. Thereafter, the BT controller determines the quality of the broadcast link between the source device and the one or more sink devices using the feedback information related to the Tx quality of the audio data packets that are fetched from the received link quality feedback data packets. The flow of the method300now proceeds to operation309.

At the operation309, subsequent to the determination of the quality of the broadcast link, the method300comprises optimizing at least one of one or more LE isochronous parameters based on the result of the determination of the quality of the broadcast link. The one or more LE isochronous parameters include but are not limited to, a number of Subevents (NSE), Burst Number (BN), Immediate Retransmission Count (IRC), and Pre-Transmission Offset (PTO) used for broadcasting the audio data packets. The optimization of the at least one of the one or more LE isochronous parameters helps in managing the quality of the broadcast link. An example of the optimization process will now be explained with reference to the method flow chart ofFIG.6of the drawings.

FIG.6illustrates a detailed flowchart of method operations for optimizing one or more LE isochronous parameters in the LE audio broadcast scenario, according to an embodiment of the disclosure.

It is to be noted that operation601and a combination of operations603and605of the method600are similar to operations305and307of the method300, respectively. Therefore, a description of the same is omitted herein for the sake of uniformity and simplicity of the disclosure.

Further, at operation607, the BT controller209determines whether the quality of the broadcast link is good or bad by comparing the determined quality of the broadcast link with a predefined threshold value. In case the result of the determination at operation607indicates that the determined quality of the broadcast link is less than the predefined threshold value then it means that the quality of the broadcast link is bad. Further, the flow of the method600proceeds to operation609.

At operation609, the BT controller209is configured to determine a reason behind the bad quality of the broadcast link. If it is determined that the reason behind the bad quality of the broadcast link is interference, then in that case the BT controller209at operation613is further configured to optimize the one or more LE isochronous parameters to increase the Retransmission Number (RTN) to improve packet reception at the one or more sink devices. In particular, the BT controller209may change a value of the IRC. The value of the IRC is controlled by the BT controller209by adjusting ISO parameters like NSE and BN.

In case the result of the determination at operation607indicates that the determined quality of the broadcast link is less than the predefined threshold value then it means that the quality of the broadcast link is bad. In such a case, the BT controller209may increase a periodicity of the transmission of the reserved Rx slot information to the one or more sink devices.

In accordance with some embodiment of the disclosure, the BT controller209, at operation613, may also update channel map information of audio data packets in the case the determined quality of the broadcast link is bad and the reason behind the bad broadcast link is interference. The reason behind the bad broadcast link is determined based on the information included in the received link quality feedback data packets. Further, the BT controller209transmits, via the Tx module107, the updated channel map information to the one or more sink devices in a PDU in the control subevent.

However, if at operation609it is determined that the reason behind the bad quality of the broadcast link is the poor RSSI at the one or more sink devices, then in that case the BT controller209, at operation615, is further configured to modify channel coding scheme of the audio data packets and transmit the audio data packets having the modified channel coding scheme to the one or more sink devices. Also, if it is determined that a greater number of packets indicates poor RSSI strength then in such case, the BT controller209, at operation615, may increase the Tx Power of the source device. Here, the poor RSSI strength means that the one or more sink devices are located at a far distance from the source device.

Further, in a case, if the result of the determination at operation607indicates that the determined quality of the broadcast link is greater than the predefined threshold value then it means that the quality of the broadcast link is good. Therefore, in such a case at operation611, the BT controller209is configured to optimize the plurality of one or more isochronous parameters to decrease the RTN. In particular, the BT controller209may change a value of the IRC. The value of the IRC is controlled by the BT controller209by adjusting ISO parameters like NSE and BN. The decrease in IRC is intended to reduce unnecessary retransmission of audio packets to the one or more sink devices and results in a reduction in power consumption at the source device.

In accordance with an embodiment of the disclosure, if the quality of the broadcast link is good, then the BT controller209, at operation611, may also optimize QOS parameters like but not limited to the sampling frequency, SDU Interval, Max SDU size, etc. to increase the quality of the audio sound to be reproduced at the one or more sink devices. For e.g., the audio quality is better in case of sampling rate 48K>44.1K>32K>16K>8K.

In case the result of the determination at operation607indicates that the determined quality of the broadcast link is greater than the predefined threshold value then it means that the quality of the broadcast link is good. In such a case, the BT controller209may decrease a periodicity of the transmission of the reserved Rx slot information to the one or more sink devices.

In view of the above-described embodiments, due to the optimization of the more LE isochronous parameters, QoS parameters, channel coding scheme, and controlling retransmissions of audio packets in accordance with real-time link quality feedback information, it became possible to improve the audio quality in the LE audio broadcast scenario and also the unnecessary retransmission of the isochronous data packets is restricted. Further, due the optimization as per the method and system of the disclosure also results in reducing the power consumption at the source device side. Thus, the method and audio system of the disclosure results in improvement of the audio quality and reliability in the LE audio broadcast scenario where there is no acknowledgment mechanism and is generally unreliable.

FIG.7illustrates another implementation example of the audio system, according to an embodiment of the disclosure.

Referring toFIG.7, the audio system includes a family of devices700including a Broadcast Source Device701, a plurality of smart assistant devices including Primary Broadcast Assistant Device703and Secondary Broadcast Assistant devices705, and one or more broadcast sink devices including Broadcast Sink Device707A and Broadcast Sink Device707B. Here, two sink devices and two secondary smart assistant devices are used as an example. However, a number of the secondary smart assistant devices and the sink devices can be changed as per other configurations of the audio systems. Therefore, those skilled in the art will appreciate that the aforementioned example of the audio system is merely exemplary and is not intended to limit the scope of the disclosure.

Each of the Broadcast Source Device701, Primary Broadcast Assistant Device703, and Secondary Broadcast Assistant devices705may include the processing engine111or the BT controller as described above inFIGS.1B and2to control operations and communication between each other. A detailed operation and functionalities of the processing engine111or the BT controller209in accordance withFIG.7will be explained in detail with the help of method800ofFIG.8of drawings.

FIG.8illustrates a detailed flowchart of method operations for optimizing one or more LE isochronous parameters in the LE audio broadcast scenario with reference toFIG.7, according to an embodiment of the disclosure.

At operation801of the method800, the BT controller209or processing engine111of each of the broadcast assistant devices (E.g., Primary Broadcast Assistant Device703and each of the Secondary Broadcast Assistant devices705) is configured to form a family group of the broadcast assistant devices using a user account registered on a corresponding broadcast assistant device of the broadcast assistant devices.

At operation803, the BT controller209or processing engine111of the Broadcast Source Device701is configured to assign a primary role to one of the Broadcast Assistant devices and the assistant device to which the primary role is assigned can be referred to as the Primary Broadcast Assistant device.

At operation805, the BT controller209of the Secondary Broadcast Assistant devices705sends, to the Primary Broadcast Assistant Device703, LE advertisement which contains family Account ID and link quality feedback data packets having PDU indicating a link quality transition from good to bad or bad to good.

At operation807, the BT controller209of the Primary Broadcast Assistant Device703establishes a LE connection with the Broadcast Source Device701. Thereafter, at operation809, the BT controller209of the Primary Broadcast Assistant Device703determines the quality of the broadcast link between the Broadcast Source Device701and the Broadcast Sink Devices707A and707B based on all the Advertisements received from Broadcast Assistant Devices. Further, the BT controller209of the Primary Broadcast Assistant Device703may also determine whether the determined quality of the broadcast link is transitioned from bad to good or good to bad. If it is determined that there is a transition in the broadcast link quality then, the BT controller209of the Primary Broadcast Assistant Device703sends an updated link quality indication to the Broadcast Source Device701via the established LE connection.

Further, at operation811, the BT controller209of the Primary Broadcast Assistant Device703may determine whether the determined quality of the broadcast link is good or bad by comparing it with the predefined threshold value, and on a basis of the result of this determination, the method operations811,813,817,819, and815are performed. Each of the operations performed by the BT controller209of the Primary Broadcast Assistant Device703at the method operations811,813,817,819, and815are similar to that of the method operations607,609,613,615, and611, respectively. Therefore, the description of the method operations811,813,817,819, and815are omitted herein for the sake of uniformity and simplicity of the disclosure.

The audio system and method of the disclosure can be used in a variety of applications such as, but are not limited to, sharing of personal music from a smartphone to friends by sending music streams to multiple users, in educational microphones by sending voice stream to multiple users, location-based audio sharing in a gym, silent disco, and in a place where loud sound is prohibited. Those skilled in the art will appreciate that the aforementioned use case examples of the audio system and the above-described method for improving the audio quality are merely exemplary and are not intended to limit the scope of the disclosure.

The drawings and the forgoing description give examples of embodiments. Those skilled in the art will appreciate that one or more of the described elements may well be combined into a single functional element. Alternatively, certain elements may be split into multiple functional elements. Elements from one embodiment may be added to another embodiment. For example, orders of processes described herein may be changed and are not limited to the manner described herein.

Moreover, the actions of any flow diagram need not be implemented in the order shown; nor do all of the acts necessarily need to be performed. Also, those acts that are not dependent on other acts may be performed in parallel with the other acts. The scope of embodiments is by no means limited by these specific examples. Numerous variations, whether explicitly given in the specification or not, such as differences in structure, dimension, and use of material, are possible. The scope of embodiments is at least as broad as given by the following claims.