Method and apparatus for controlling multi-channel audio for ble speaker, phone and TV

Abstract

A method performed by a source, according to one embodiment of the present specification, comprises the steps of: scanning advertisements of speakers related to a surround sound system; connecting to the speakers; and transmitting information including at least one parameter to each of the speakers. The at least one parameter includes a volume control parameter.

Description

Method and device for multi-channel audio control for BLE speakers, phones, and TVs

[0001] This disclosure relates to a method and apparatus for multi-channel audio control for BLE speakers, phones and TVs.

[0002] With the growing demand for immersive content consumption environments, interest in multichannel audio systems that deliver three-dimensional playback in user-centric spaces is growing. However, conventional Bluetooth-based audio systems are primarily limited to two-channel stereo output (left and right), posing structural limitations in implementing spatial audio (surround sound) using multiple wireless speakers. In particular, despite the popularization of portable Bluetooth speakers, the technology for integrating them with home TVs or set-top boxes to create a stable, low-latency multichannel audio environment remains inadequate.

[0003] The purpose of this specification is to provide a method for configuring a multichannel audio environment.

[0004] The technical problems to be achieved in this specification are not limited to the technical problems mentioned above, and other technical problems not mentioned can be clearly understood by a person having ordinary skill in the technical field to which this specification pertains from the description below.

[0005] According to one embodiment of the present disclosure, a method performed by a source for solving the above-described problem comprises the steps of scanning advertisements of speakers associated with a surround sound system, connecting to the speakers, and transmitting information including at least one parameter to each of the speakers. Each advertisement includes information indicating whether a Surround Sound Audio Profile (SSAP) is supported by each speaker. The at least one parameter is characterized in that it includes a volume control parameter. As described above, a multi-channel audio environment can be supported through connection between a source (e.g., a TV, a sound bar, a phone) that operates as an SSAP assistant and a plurality of speakers.

[0006] According to an embodiment of the present disclosure, when a source scans advertisements and the source is connected to speakers associated with a surround sound system, information including at least one parameter (e.g., a volume control parameter) is transmitted to each speaker. Since the operations / roles and parameters of the entities (sources and speakers) configuring the surround sound system are clearly defined, a multi-channel audio environment can be configured more effectively. Specifically, in configuring a multi-channel audio environment, improved volume control efficiency, reduced delay, improved reliability, increased ease of maintenance, and improved system reliability can be expected.

[0007] Additionally, it can provide multi-channel spatial sound that meets surround audio needs that could not be met through existing Bluetooth 2-channel audio.

[0008] The accompanying drawings are intended to aid understanding of the present specification and may provide embodiments of the present specification along with detailed descriptions. However, the technical features of the present specification are not limited to specific drawings, and the features disclosed in each drawing may be combined with each other to form new embodiments. Reference numerals in each drawing may indicate structural elements.

[0009] Figure 1 is a schematic diagram showing an example of a wireless communication system using the Bluetooth low energy technology proposed in this specification.

[0010] FIG. 2 shows an example of an internal block diagram of a device capable of implementing the methods proposed in this specification.

[0011] Figure 3 shows an example of a Bluetooth communication architecture to which the methods proposed in this specification can be applied.

[0012] Figure 4 shows an example of the structure of the GATT (Generic Attribute Profile) of Bluetooth low energy.

[0013] FIG. 5 is a flowchart illustrating an example of a connection procedure method in Bluetooth low energy technology to which various embodiments of the present specification can be applied.

[0014] FIG. 6 illustrates an example of a system structure in which multi-channel audio signals are transmitted between a BLE-based TV transmitting device and multiple BLE audio receiving speakers.

[0015] FIG. 7 illustrates an example of a compensation procedure for synchronizing image processing delay and audio processing delay in a Bluetooth low-latency audio system proposed in this specification.

[0016] FIG. 8 illustrates an example of a test stream-based calibration procedure for measuring and adjusting the sound pressure level of each speaker based on a user position in a BLE-based audio system proposed in this specification.

[0017] FIG. 9 illustrates an example of an inter-speaker synchronization correction structure for correcting sound synchronization error due to a difference in distance between a TV speaker and a rear speaker in a multi-channel audio system proposed in this specification.

[0018] FIG. 10 illustrates an example of a speaker-to-speaker synchronization structure for compensating for sound synchronization errors due to distance differences between rear speakers in a multi-channel audio system proposed in this specification.

[0019] FIG. 11 is a diagram illustrating the roles of devices defined for audio broadcasting to which the method proposed in this specification can be applied.

[0020] FIG. 12 is a diagram illustrating key elements of an audio broadcast assistant to which the method proposed in this specification can be applied.

[0021] FIG. 13 is a diagram illustrating profiles and services used by an audio broadcast assistant to which the method proposed in this specification can be applied.

[0022] FIG. 14 is a diagram illustrating an audio broadcast assistant application to which the method proposed in this specification can be applied.

[0023] FIG. 15 is a diagram illustrating roles defined for audio broadcast / unicast to which the method proposed in this specification can be applied.

[0024] FIG. 16 illustrates an example of an overall system configuration for multi-channel audio transmission between a BLE-based TV and multiple audio receiving devices proposed in this specification and a profile structure based on Surround Sound Audio Profile (SSAP).

[0025] Figure 17 is a drawing illustrating the scope and purpose of the SSAP proposed in this specification.

[0026] FIG. 18 is an example of multi-channel transmission using SSAP according to an embodiment of the present specification.

[0027] FIG. 19 is another example of multi-channel transmission using SSAP according to an embodiment of the present specification.

[0028] FIG. 20 is a diagram illustrating a multi-channel audio connection control operation using a control assistant according to an embodiment of the present specification.

[0029] FIG. 21 is a diagram illustrating a multi-channel audio connection control operation using a control assistant according to an embodiment of the present specification at time intervals.

[0030] FIG. 22 is a diagram showing the role of a conventional broadcast assistant and the role of a broadcast assistant according to an embodiment of the present specification.

[0031] FIG. 23a is a diagram illustrating a multi-channel audio connection control operation between a BLE-based TV and multiple speakers using a control assistant according to an embodiment of the present specification.

[0032] FIG. 23b is a diagram illustrating an LE ACL / Advertising-related payload for a multi-channel audio connection control operation between a BLE-based TV and multiple speakers using a control assistant according to an embodiment of the present specification.

[0033] FIG. 24 is a diagram illustrating a situation in which the battery of a specific speaker is very low in a multi-channel transmission operation according to an embodiment of the present specification.

[0034] Figure 25 is a diagram illustrating operation according to the conventional method in a situation where the battery of a specific speaker is very low in a multi-channel transmission operation.

[0035] FIG. 26 is a diagram illustrating an operation according to an embodiment of the present specification in a situation where the battery of a specific speaker is very low in a multi-channel transmission operation.

[0036] FIG. 27 is a diagram showing an example of a CH change operation due to removal of a specific speaker during a 4 CH broadcast operation for 4 speakers according to an embodiment of the present specification.

[0037] FIG. 28 is a diagram showing another example of a CH change operation due to removal of a specific speaker during a 4 CH broadcast operation for 4 speakers according to an embodiment of the present specification.

[0038] FIG. 29 is a diagram illustrating an operation of changing channel settings by utilizing periodic BLE broadcast and response according to an embodiment of the present specification.

[0039] FIG. 30 is a flowchart illustrating a method performed by a source according to one embodiment of the present specification.

[0040] FIG. 31 is a flowchart illustrating a method performed by a speaker according to another embodiment of the present specification.

[0041] In various embodiments of this specification, “A or B” can mean “only A,” “only B,” or “both A and B.” In other words, in various embodiments of this specification, “A or B” can be interpreted as “A and / or B.” For example, in various embodiments of this specification, “A, B or C” can mean “only A,” “only B,” “only C,” or “any combination of A, B and C.”

[0042] In various embodiments of this specification, a slash ( / ) or a comma may mean "and / or." For example, "A / B" may mean "A and / or B." Accordingly, "A / B" may mean "only A," "only B," or "both A and B." For example, "A, B, C" may mean "A, B, or C."

[0043] In various embodiments of the present specification, “at least one of A and B” may mean “only A,” “only B,” or “both A and B.” Furthermore, in various embodiments of the present specification, the expressions “at least one of A or B” or “at least one of A and / or B” may be interpreted as equivalent to “at least one of A and B.”

[0044] Additionally, in various embodiments of the present specification, “at least one of A, B and C” can mean “only A,” “only B,” “only C,” or “any combination of A, B and C.” Additionally, “at least one of A, B or C” or “at least one of A, B and / or C” can mean “at least one of A, B and C.”

[0045] Figure 1 is a schematic diagram showing an example of a wireless communication system using the Bluetooth low energy technology proposed in this specification.

[0046] A wireless communication system (100) includes at least one server device (Server Device, 120) and at least one client device (Client Device, 110).

[0047] The server device and client device perform Bluetooth communication using Bluetooth Low Energy (BLE, hereinafter referred to as 'BLE' for convenience) technology.

[0048] First, BLE technology has a relatively small duty cycle compared to Bluetooth BR / EDR (Basic Rate / Enhanced Data Rate) technology, allows for low-cost production, and significantly reduces power consumption through low-speed data transmission rates, enabling operation for more than a year using a coin cell battery.

[0049] Additionally, BLE technology simplifies the connection process between devices and is designed to have a smaller packet size compared to Bluetooth BR / EDR technology.

[0050] In BLE technology, (1) the number of RF channels is 40, (2) the data transmission speed supports 1 Mbps, (3) the topology is a scatternet structure, (4) the latency is 3 ms, (5) the maximum current is 15 mA or less, (6) the output power is 10 mW (10 dBm) or less, and (7) it is mainly used in applications such as mobile phones, watches, sports, healthcare, sensors, and device control.

[0051] The server device (120) can operate as a client device in a relationship with other devices, and the client device can operate as a server device in a relationship with other devices. That is, in a BLE communication system, any one device can operate as a server device or a client device, and, if necessary, can operate as a server device and a client device simultaneously.

[0052] The above server device (120) may be expressed as a data service device, a client device, a slave device, a server, a conductor, a host device, a gateway, a sensing device, a monitoring device, a first device, a second device, etc.

[0053] The above client device (110) can be expressed as a server device (master device), a master, a client, a member, a sensor device, a sink device, a collector, a third device, a fourth device, etc.

[0054] The server device and the client device are the main components of the wireless communication system, and the wireless communication system may include other components in addition to the server device and the client device.

[0055] The above server device refers to a device that receives data from a client device and performs direct communication with the client device, thereby providing data to the client device through a response when receiving a data request from the client device.

[0056] Additionally, the server device sends a notification message and an indication message to the client device to provide data information to the client device. Additionally, when the server device transmits an indication message to the client device, it receives a confirmation message corresponding to the indication message from the client.

[0057] In addition, the server device can provide data information to a user through an output unit (Display Unit) or receive a request input from a user through an input unit (User Input Interface) in the process of transmitting and receiving notifications, instructions, and confirmation messages to and from a client device.

[0058] Additionally, the server device can read data from a memory unit or write new data to the memory unit during the process of transmitting and receiving messages with the client device.

[0059] Additionally, one server device can be connected to multiple client devices, and can easily reconnect (or connect) to the client devices by utilizing bonding information.

[0060] The above client device (120) refers to a device that requests data information and data transmission from a server device.

[0061] The client device receives data from the server device through a notification message, an instruction message, etc., and when receiving an instruction message from the server device, sends a confirmation message in response to the instruction message.

[0062] Likewise, the client device can provide information to the user through an output unit or receive input from the user through an input unit during the process of transmitting and receiving messages with the server device.

[0063] Additionally, the client device can read data from memory or write new data to the memory during the process of transmitting and receiving messages with the server device.

[0064] Hardware components such as the output section, input section, and memory of the above server device and client device will be examined in detail in Fig. 2.

[0065] Additionally, the wireless communication system can establish a Personal Area Network (PAN) via Bluetooth technology. For example, the wireless communication system can establish a private piconet between devices, enabling the quick and secure exchange of files, documents, and other information.

[0066] FIG. 2 shows an example of an internal block diagram of a device capable of implementing the methods proposed in this specification.

[0067] As illustrated in FIG. 2, the server device (110) includes an input unit (User Input Interface, 112), a power supply unit (Power Supply Unit, 113), a control unit (Control Unit, 114), a memory unit (Memory Unit, 115), a network interface (Network Interface, 116) including a Bluetooth interface, storage (Storage, 117), an output unit (Display Unit, 118), and a multimedia module (Multi Media Module, 119).

[0068] The input unit (User Input Interface, 112), power supply unit (Power Supply Unit, 113), control unit (Control Unit, 114), memory (Memory Unit, 115), network interface (Network Interface, 116) including Bluetooth interface, storage (Storage, 117), output unit (Display Unit, 118), and multimedia module (Multi media Module, 119) are functionally interconnected to perform the method proposed in this specification.

[0069] In addition, as illustrated in FIG. 2, the client devices (#1 and #2) (120) include an input unit (User Input Interface, 122), a power supply unit (Power Supply Unit, 123), a control unit (Control Unit, 124), a memory unit (Memory Unit, 125), a network interface (Network Interface, 126) including a Bluetooth interface, storage (Storage, 127), an output unit (Display Unit, 128), and a multimedia module (Multi media Module, 129).

[0070] The input unit (User Input Interface, 122), power supply unit (Power Supply Unit, 123), control unit (Control Unit, 124), memory (Memory Unit, 125), network interface (Network Interface, 126) including Bluetooth interface, storage (Storage, 127), output unit (Display Unit, 128), and multimedia module (Multi media Module, 129) are functionally interconnected to perform the method proposed in this specification.

[0071] The above network interface (116, 126) refers to a unit (or module) capable of transmitting request / response, command, notification, instruction / confirmation messages, etc. or data between devices using Bluetooth technology.

[0072] The above memory (115, 125) is a unit implemented in various types of devices, and refers to a unit in which various types of data are stored. In addition, the storage (117, 127) refers to a unit that performs a function similar to memory.

[0073] The above control unit (114, 124) refers to a module that controls the overall operation of the server device (110) or client device (120), and controls to request transmission of a message to a network interface or to process a received message.

[0074] The above control unit (114, 124) may include an application-specific integrated circuit (ASIC), another chipset, a logic circuit, and / or a data processing device.

[0075] The above memory (115, 125) may include a ROM (read-only memory), a RAM (random access memory), a flash memory, a memory card, a storage medium, and / or other storage devices.

[0076] The above memory (115, 125) may be internal or external to the processor (114, 124) and may be connected to the processor (114, 124) by various well-known means.

[0077] The above output unit (118, 128) refers to a module for providing device status information and message exchange information to the user through a screen.

[0078] The above power supply unit (power supply unit, 113, 123) refers to a module that receives external power and internal power under the control of the control unit and supplies the power required for the operation of each component.

[0079] As discussed above, BLE technology has a small duty cycle and can significantly reduce power consumption through low data rates.

[0080] Figure 3 shows an example of a Bluetooth communication architecture to which the methods proposed in this specification can be applied.

[0081] Specifically, FIG. 3 shows an example of the architecture of Bluetooth LE (Low Energy).

[0082] As illustrated in FIG. 3, the BLE architecture includes a controller stack (Controller stackACK) operable to handle timing-critical wireless device interfaces and a host stack (Host stackACK) operable to handle high level data.

[0083] The above Controller stack may be referred to as a Controller, but to avoid confusion with the processor, which is an internal component of the device mentioned in FIG. 2 above, it will be referred to as a Controller stackACK hereinafter.

[0084] First, the controller stack may be implemented using a communication module that may include a Bluetooth radio, and a processor module that may include a processing device, such as a microprocessor.

[0085] The host stack can be implemented as part of an OS running on a processor module, or as an instantiation of a package on top of the OS.

[0086] In some cases, the controller stack and the host stack may operate or execute on the same processing device within a processor module.

[0087] The host stack includes GAP (Generic Access Profile, 310), GATT-based Profiles (320), GATT (Generic Attribute Profile, 330), ATT (Attribute Protocol, 340), SM (Security Manager, 350), and L2CAP (Logical Link Control and Adaptation Protocol, 360). However, the host stack is not limited to this and may include various protocols and profiles.

[0088] The host stack multiplexes various protocols, profiles, etc. provided above Bluetooth using L2CAP.

[0089] First, L2CAP (Logical Link Control and Adaptation Protocol,360) provides a single bidirectional channel for transmitting data to a specific protocol or profile.

[0090] L2CAP may be capable of multiplexing data between upper layer protocols, segmenting and reassembling packages, and managing multicast data transmission.

[0091] BLE uses three fixed channels (one for signaling CH, one for Security Manager, and one for Attribute protocol).

[0092] On the other hand, BR / EDR (Basic Rate / Enhanced Data Rate) uses dynamic channels and supports protocol service multiplexer, retransmission, streaming mode, etc.

[0093] SM (Security Manager, 350) is a protocol for authenticating devices and providing key distribution.

[0094] ATT (Attribute Protocol, 340) defines the rules for accessing data from other devices in a server-client architecture. ATT has six message types: Request, Response, Command, Notification, Indication, and Confirmation.

[0095] That is, ① Request and Response messages: The Request message is a message for requesting specific information from a client device to a server device, and the Response message is a response message to the Request message, and refers to a message transmitted from the server device to the client device.

[0096] ② Command message: A message sent from a client device to a server device to instruct a specific action command. The server device does not send a response to the Command message to the client device.

[0097] ③ Notification message: A message sent from a server device to a client device for notification of events, etc.; the client device does not send a confirmation message for the Notification message to the server device.

[0098] ④ Indication and Confirm messages: Messages sent from the server device to the client device for notification of events, etc. Unlike the Notification message, the client device sends a confirmation message for the Indication message to the server device.

[0099] GAP (Generic Access Profile) is a new layer implemented for BLE technology, which is used to control role selection for communication between BLE devices and how multi-profile operation occurs.

[0100] Additionally, GAP is primarily used in device discovery, connection creation, and security procedures, defines how to provide information to users, and defines the types of attributes as follows:

[0101] ① Service: Defines the basic operation of the device through a combination of data-related behaviors.

[0102] ② Include: Defines the relationship between services

[0103] ③ Characteristics: Data values ​​used in the service

[0104] ④ Behavior: Computer-readable format defined as UUID (Universal Unique Identifier, value type)

[0105] GATT-based Profiles are profiles that depend on GATT and are primarily applied to BLE devices. GATT-based Profiles include Battery, Time, FindMe, Proximity, Time, and Object Delivery Service. The specifics of GATT-based Profiles are as follows.

[0106] Battery: How to exchange battery information

[0107] Time: A method for exchanging time information

[0108] FindMe: Distance-based alarm service

[0109] Proximity: How to Exchange Battery Information

[0110] Time: A method for exchanging time information

[0111] GATT can function as a protocol that describes how ATT is used when composing services. For example, GATT can be used to specify how ATT attributes are grouped into services, and can be used to describe the features associated with services.

[0112] Therefore, GATT and ATT can use features to describe the state and services of a device, how features relate to each other, and how they are used.

[0113] The controller stack includes a physical layer (390), a link layer (380), and a host controller interface (370).

[0114] The physical layer (wireless transmission / reception module, 390) is a layer that transmits and receives 2.4 GHz wireless signals and uses GFSK (Gaussian Frequency Shift Keying) modulation and a frequency hopping technique consisting of 40 RF channels.

[0115] The link layer (380) transmits or receives Bluetooth packets.

[0116] Additionally, the link layer performs advertising and scanning functions using three advertising channels, then creates a connection between devices, and provides the ability to send and receive data packets of up to 42 bytes through 37 data channels.

[0117] HCI (Host Controller Interface) provides an interface between the Host stack and the Controller stack, allowing the Host stack to provide commands and data to the Controller stack, and allowing the Controller stack to provide events and data to the Host stack.

[0118] Below, we will briefly look at the procedures of Bluetooth Low Energy (BLE) technology.

[0119] BLE procedures can be divided into device filtering procedures, advertising procedures, scanning procedures, discovering procedures, and connecting procedures.

[0120] Device Filtering Procedure

[0121] Device filtering procedures are a way to reduce the number of devices that respond to requests, instructions, notifications, etc. in the controller stack.

[0122] When a request is received from any device, since it is unnecessary to respond to it, the controller stack can control the power consumption of the BLE controller stack by reducing the number of requests transmitted.

[0123] An advertising device or scanning device may perform the above device filtering procedure to limit the devices that receive advertising packets, scan requests, or connection requests.

[0124] Here, an advertising device refers to a device that transmits an advertising event, i.e., performs an advertisement, and is also expressed as an advertiser.

[0125] A scanning device is a device that performs scanning and transmits scan requests.

[0126] In BLE, when a scanning device receives some advertising packets from an advertising device, the scanning device must send a scan request to the advertising device.

[0127] However, if a device filtering procedure is used and transmission of scan requests is unnecessary, the scanning device may ignore advertising packets transmitted from the advertising device.

[0128] Device filtering procedures may also be used during the connection request process. If device filtering is used during the connection request process, the connection request is ignored, eliminating the need to send a response to the connection request.

[0129] Advertising Procedure

[0130] An advertising device performs an advertising procedure to perform non-directional broadcasts to devices within the area.

[0131] Here, non-directional broadcast refers to broadcast in all directions rather than broadcasting in a specific direction.

[0132] In contrast, a directional broadcast refers to a broadcast in a specific direction. A non-directional broadcast occurs without a connection procedure between an advertising device and a device in a listening (or listening) state (hereinafter referred to as a listening device).

[0133] The advertising process is used to establish a Bluetooth connection with a nearby initiating device.

[0134] Alternatively, the advertising procedure may be used to provide periodic broadcasts of user data to scanning devices listening on the advertising channel.

[0135] In the advertising process, all advertisements (or advertising events) are broadcast through the advertising physical channel.

[0136] Advertising devices can receive scan requests from listening devices that are listening to obtain additional user data from the advertising device. The advertising device transmits a response to the scan request to the device that sent the scan request over the same advertising physical channel as the advertising physical channel that received the scan request.

[0137] Broadcast user data sent as part of advertising packets is dynamic data, whereas scan response data is typically static data.

[0138] An advertising device can receive a connection request from an initiating device on an advertising (broadcast) physical channel. If the advertising device uses a connectable advertising event and the initiating device is not filtered by the device filtering procedure, the advertising device stops advertising and enters connected mode. The advertising device can resume advertising after entering connected mode.

[0139] Scanning Procedure

[0140] A device performing scanning, i.e., a scanning device, performs a scanning procedure to listen for non-directional broadcasts of user data from advertising devices using an advertising physical channel.

[0141] The scanning device transmits a scan request to the advertising device via the advertising physical channel to request additional data from the advertising device. The advertising device transmits a scan response, which is a response to the scan request, including the additional data requested from the scanning device via the advertising physical channel.

[0142] The above scanning procedure can be used while connecting with other BLE devices in a BLE piconet.

[0143] If the scanning device is in initiator mode, which means that it can receive a broadcasted advertising event and initiate a connection request, the scanning device can initiate a Bluetooth connection with the advertising device by sending a connection request to the advertising device over the advertising physical channel.

[0144] When a scanning device sends a connection request to an advertising device, the scanning device stops initiator mode scanning for further broadcasts and enters connection mode.

[0145] Discovery Procedure

[0146] Devices capable of Bluetooth communication (hereinafter referred to as “Bluetooth devices”) perform advertising and scanning procedures to discover nearby devices or to be discovered by other devices within a given area.

[0147] The discovery process is performed asymmetrically. A Bluetooth device attempting to locate other devices in its vicinity is called a discovering device and listens for devices advertising scannable advertising events. A Bluetooth device discovered and available to other devices is called a discoverable device and actively broadcasts advertising events over the advertising (broadcast) physical channel to make it scannable.

[0148] Both the discovering device and the discoverable device may already be connected to other Bluetooth devices in the piconet.

[0149] Connecting Procedure

[0150] The connection procedure is asymmetric, requiring one Bluetooth device to perform an advertising procedure while another Bluetooth device performs a scanning procedure.

[0151] That is, the advertising process can be targeted, resulting in only one device responding to the advertisement. After receiving an accessible advertising event from the advertising device, a connection can be initiated by sending a connection request to the advertising device via the advertising (broadcast) physical channel.

[0152] Next, we will briefly look at the operating states in BLE technology, namely Advertising State, Scanning State, Initiating State, and Connection State.

[0153] Advertising State

[0154] The Link Layer (LL) enters the Advertising state at the direction of the host (stack). When the Link Layer is in the Advertising state, it transmits Advertising Packet Data Units (PDUs) in Advertising events.

[0155] Each advertising event consists of at least one advertising PDU, which are transmitted via the advertising channel indices used. An advertising event may terminate when each advertising PDU has been transmitted via the advertising channel indices used, or may terminate earlier if the advertising device needs to free up space for other functions.

[0156] Scanning State

[0157] The link layer enters the scanning state at the direction of the host (stack). In the scanning state, the link layer listens for advertising channel indices.

[0158] There are two types of scanning states: passive scanning and active scanning, and each scanning type is determined by the host.

[0159] No separate time or advertising channel index is defined for performing scanning.

[0160] During the scanning state, the link layer listens for advertising channel indices for the duration of the scanWindow. The scanInterval is defined as the interval between the start points of two consecutive scan windows.

[0161] The link layer must listen for the completion of all scan intervals in the scan window, as directed by the host, provided there are no scheduling conflicts. In each scan window, the link layer must scan a different advertising channel index. The link layer uses all available advertising channel indices.

[0162] In passive scanning, the link layer only receives packets and does not transmit any packets.

[0163] When actively scanning, the link layer listens to the advertising device for advertising PDUs and depending on the advertising PDU type, may request additional information about the advertising device.

[0164] Initiating State

[0165] The link layer enters the initiated state at the direction of the host (stack).

[0166] When the link layer is in the initiating state, the link layer listens for advertising channel indices.

[0167] During the initiation state, the link layer listens for advertising channel indices during the scan window period.

[0168] connection state

[0169] The link layer enters a connected state when the device performing the connection request, i.e., the initiating device, sends a CONNECT_REQ PDU to the advertising device, or when the advertising device receives a CONNECT_REQ PDU from the initiating device.

[0170] Once a connection enters the connected state, it is considered established. However, the connection need not be considered established at the time it enters the connected state. The only difference between a newly created connection and an established connection is the link-layer connection supervision timeout value.

[0171] When two devices are connected, they act in different roles.

[0172] The link layer that performs the master role is called the master, and the link layer that performs the slave role is called the slave. The master controls the timing of connection events, and connection events indicate the point in time when the master and slave are synchronized.

[0173] Below, we will briefly examine the packets defined in the Bluetooth interface. BLE devices use the packets defined below.

[0174] Packet Format

[0175] The Link Layer has only one packet format, which is used for both advertising channel packets and data channel packets.

[0176] Each packet consists of four fields: Preamble, Access Address, PDU, and CRC.

[0177] When a packet is transmitted on an advertising physical channel, the PDU will be an advertising channel PDU, and when a packet is transmitted on a data physical channel, the PDU will be a data channel PDU.

[0178] Advertising Channel PDU

[0179] Advertising channel PDUs (Packet Data Units) have a 16-bit header and payloads of various sizes.

[0180] The PDU type field of the advertising channel PDU included in the header indicates the PDU type as defined in Table 1 below.

[0181]

[0182] Advertising PDU

[0183] The advertising channel PDU types below are called advertising PDUs and are used in specific events.

[0184] ADV_IND: Connectable non-directional advertising event

[0185] ADV_DIRECT_IND: Connectable directional advertising event

[0186] ADV_NONCONN_IND: Non-directional ad event that is not reachable

[0187] ADV_SCAN_IND: Scannable non-directional ad event

[0188] The above PDUs are transmitted by the link layer in the advertising state and received by the link layer in the scanning state or initiating state.

[0189] Scanning PDU

[0190] The advertising channel PDU type below is called a scanning PDU and is used in the conditions described below.

[0191] SCAN_REQ: Sent by the link layer in scanning state and received by the link layer in advertising state.

[0192] SCAN_RSP: Sent by the link layer in advertising state and received by the link layer in scanning state.

[0193] Initiating PDU

[0194] The advertising channel PDU type below is called an initiation PDU.

[0195] CONNECT_REQ: Sent by the link layer in the initiating state and received by the link layer in the advertising state.

[0196] Data Channel PDU

[0197] A data channel PDU has a 16-bit header, a payload of variable size, and may include a Message Integrity Check (MIC) field.

[0198] The procedures, states, packet formats, etc. in BLE technology discussed above can be applied to perform the methods proposed in this specification.

[0199] Figure 4 shows an example of the structure of the GATT (Generic Attribute Profile) of Bluetooth low energy.

[0200] Referring to Figure 4, a structure for exchanging profile data of Bluetooth low energy can be examined.

[0201] Specifically, GATT (Generic Attribute Profile) defines how to exchange data using services and characteristics between Bluetooth LE devices.

[0202] Typically, a peripheral device (e.g., a sensor device) acts as a GATT server and has definitions for services and characteristics.

[0203] To read or write data, a GATT client sends a data request to a GATT server, and all operations (transactions) are initiated by the GATT client and receive responses from the GATT server.

[0204] The GATT-based operation structure used in Bluetooth LE is based on profiles, services, and characteristics, and can form a vertical structure as shown in Fig. 5.

[0205] The above profile consists of one or more services, and the services may consist of one or more characteristics or other services.

[0206] The above service serves to logically divide data into units and may include one or more characteristics or other services. Each service has a 16-bit or 128-bit identifier called a Universal Unique Identifier (UUID).

[0207] The above characteristic is the lowest unit in the GATT-based operation structure. The characteristic contains only one piece of data and, similar to the above service, has a 16-bit or 128-bit UUID.

[0208] The above characteristics are defined by the values ​​of various pieces of information, and each piece of information requires one attribute. Multiple consecutive attributes can be used for the above characteristics.

[0209] The above attribute consists of four components and has the following meanings:

[0210] - handle: address of the property

[0211] - Type: Type of property

[0212] - Value: The value of the property

[0213] - Permission: Access rights to properties

[0214] FIG. 5 is a flowchart showing an example of a connection procedure method in Bluetooth low energy technology to which the present specification can be applied.

[0215] The server transmits advertising messages to the client through three advertising channels (S5010).

[0216] A server may be called an Advertiser before connection, and a Master after connection. An example of such a server may be a sensor (e.g., a temperature sensor).

[0217] Additionally, a client may be referred to as a "Scanner" before connection and as a "Slave" after connection. An example of a client may be a smartphone.

[0218] As previously discussed, Bluetooth communicates across 40 channels over the 2.4 GHz band. Of these 40 channels, three are advertising channels, used to exchange various advertising packets and other packets used to establish a connection.

[0219] The remaining 37 channels are used for data exchange after connection as data channels.

[0220] After receiving the advertisement message, the client may send a Scan Request message to the server to obtain additional data (e.g., server device name, etc.) from the server.

[0221] In this case, the server transmits a Scan Response message containing additional data in response to a Scan Request message to the client.

[0222] Here, the Scan Request message and the Scan Response message are an end of an advertising packet, and the advertising packet can only contain user data of 31 bytes or less.

[0223] Therefore, if there is data whose size is larger than 3 bytes but the overhead is too high to send the data by establishing a connection, the data is sent in two parts using a scan request message / scan response message.

[0224] Next, the client sends a connection request message to the server to establish a Bluetooth connection with the server (S5020).

[0225] Through this, a Link Layer (LL) connection is established between the server and the client.

[0226] Afterwards, the server and client perform security establishment procedures.

[0227] The secure establishment procedure may be interpreted as or performed incorporating Secure Simple Pairing.

[0228] That is, the security establishment procedure can be carried out through Phase 1 to Phase 3.

[0229] Specifically, a pairing procedure (phase 1) is performed between the server and the client (S5030).

[0230] The pairing procedure involves the client sending a pairing request message to the server, and the server sending a pairing response message to the client.

[0231] The pairing process involves exchanging authentication requirements, input / output capabilities, and key size information between devices. This information is used to determine which key generation method to use in Phase 2.

[0232] Next, as phase 2, legacy pairing or secure connections are performed between the server and the client (S5040).

[0233] In Phase 2, a 128-bit temporary key and a short term key (STK) are generated to perform legacy pairing.

[0234] - Temporary Key: Key created to generate STK

[0235] - Short Term Key (STK): Key value used to create an encrypted connection between devices.

[0236] If a secure connection is performed in Phase 2, a 128-bit Long Term Key (LTK) is generated.

[0237] - Long Term Key (LTK): A key value used not only for encrypted connections between devices but also for future connections.

[0238] Next, as phase 3, a key distribution procedure is performed between the server and the client (S5050).

[0239] This establishes a secure connection between the server and client, forming an encrypted link to enable data transmission and reception.

[0240] Isochronous Channel General

[0241] For audio signals, you can see that audio streaming data or audio data occurs periodically at Idle Event Interval intervals.

[0242] Audio data occurs periodically (or at specific time intervals) depending on its characteristics. Here, a specific time period during which audio data occurs periodically can be expressed as an Idle Event Interval. Each audio data is transmitted during each Idle Event Interval. Furthermore, each audio data can be transmitted throughout the entire Idle Event Interval or a portion of the Idle Event Interval. When transmitting audio streaming data that occurs periodically or regularly using the BLE mechanism, advertising and scanning procedures, communication procedures, and disconnection procedures must be performed each time the generated audio data is transmitted or received. However, audio data is generally generated periodically, and regardless of the amount of data, a latency guarantee for audio data transmission is essential.

[0243] However, there is a problem that latency occurs in audio data transmission when advertising and scanning procedures, communication procedures, and disconnection procedures must be performed every time new audio data is transmitted.

[0244] Audio data transmission through hearing aids (HA) or headsets can achieve higher energy efficiency by utilizing BLE technology rather than Bluetooth BR / EDR technology because the amount of data generated is relatively small. However, as previously discussed, the Data Channel Process of BLE technology requires advertising and connection for each data transmission, which results in a large overhead in data transmission. In particular, the Latency Guarantee, which is absolutely necessary for audio data transmission, cannot be guaranteed.

[0245] In addition, since the Data Channel Process of BLE technology aims to increase energy efficiency by transmitting data that occurs sporadically only when necessary and inducing deep sleep of the BLE device in other time domains, it may be difficult to apply the Data Channel Process of BLE technology to the transmission of audio data that occurs periodically.

[0246] Definition of Isochronous Channels and Related Mechanisms

[0247] A new channel, the Isochronous Channel, is defined to transmit periodically occurring data using BLE technology.

[0248] An isochronous channel is a channel used to transmit isochronous data between devices that use isochronous streams (e.g., Conductor-Member).

[0249] Isochronous data refers to data that is transmitted periodically or regularly at specific time intervals.

[0250] That is, an isochronous channel may refer to a channel through which periodically occurring data, such as audio data or voice data, is transmitted and received in BLE technology. In addition, the isochronous channel may refer to a channel through which data generated based on a user input of a game user's controller device is transmitted and received in a gaming scenario. The isochronous channel may be used to transmit and receive data with a single member, a set of one or more coordinated members, or multiple members. In addition, the isochronous channel corresponds to a flushing channel that may be used to transmit and receive important data in an isochronous stream, such as audio streaming, or in another time domain.

[0251] Composition of various embodiments of this specification

[0252] Problems with prior art

[0253] Conventional Bluetooth-based audio systems are primarily limited to two-channel stereo output, with structural limitations in implementing spatial audio (surround sound) using multiple wireless speakers. In particular, despite the popularization of portable Bluetooth speakers, the technology for linking them with home TVs or set-top boxes to create a stable, low-latency, multi-channel audio environment has not been sufficiently developed.

[0254] Summary of various embodiments of this specification

[0255] This specification provides the scope and structure of multi-channel audio technology between BLE-based TV and multiple speakers.

[0256] This specification provides a technology for controlling multi-channel audio connections between a BLE-based TV and multiple speakers using a Control Assistant installed on a TV or phone.

[0257] This specification provides a technology for controlling volume, audio quality, and transmission quality by utilizing the exchange of power status information between TVs and speakers.

[0258] This specification provides a technique for changing broadcast channel settings using periodic broadcasts and responses between TVs and speakers.

[0259] Unlike conventional low-latency products, this specification ensures compatibility by utilizing Bluetooth standard technology.

[0260] Effects of various embodiments of this specification

[0261] According to an embodiment of the present specification, a realistic movie viewing environment can be provided by providing multi-channel surround audio to a TV and multiple BT wireless speakers at home based on BLE audio.

[0262] According to the embodiments of the present specification, a BT standard compatible multi-channel audio ecosystem can be secured.

[0263] According to an embodiment of the present specification, a multi-channel audio system utilizing a BT Chip can be provided.

[0264] FIG. 6 illustrates an example of a system structure in which multi-channel audio signals are transmitted between a BLE-based TV transmitting device and multiple BLE audio receiving speakers.

[0265] Figure 6 illustrates an example system architecture that wirelessly transmits multi-channel audio signals between a TV transmitter and multiple audio receiver speakers using BLE (Bluetooth Low Energy) technology. The system of Figure 6 configures the TV as an audio transmitter (Initiator) and each speaker as an audio receiver (Acceptor), enabling a multi-channel audio environment without wired connections. It utilizes BLE's ISO channel, making it suitable for audio data transmission where time synchronization is critical.

[0266] The TV LE Audio Tx Device includes a video display, an audio decoder / encoder, a controller, and a BLE Tx interface. The audio decoder / encoder converts surround audio formats such as Dolby or DTS into PCM and encodes it into the LC3 codec suitable for BLE transmission. It also supports mono unicast transmission. The TV wirelessly transmits the processed audio signal to external speakers via the BLE Tx interface. Configuration information can be communicated bidirectionally, while the actual audio stream is transmitted unidirectionally.

[0267] The Speaker LE Audio Rx Device consists of a BLE Tx / Rx interface, an audio decoder, an LC3 decoder, a controller, and a speaker driver. Each speaker receives BLE audio data wirelessly transmitted from the TV through the BLE Tx / Rx interface. The received data is restored to the original audio signal through the LC3 decoder and audio decoder, and this signal is output as sound through the speaker driver. Speakers with Tx / Rx interfaces can be used for exchanging setting information with the TV or receiving control signals.

[0268] The system in Figure 6 operates by processing multichannel audio signals, such as 5.1 channels, from a TV and assigning and transmitting them to wireless speakers, either individually or in groups. Each speaker receives and plays audio data for its assigned channel, allowing users to experience a wireless surround sound system without the need for complex audio cable connections. This offers the advantage of increased installation flexibility and a cleaner user experience.

[0269] FIG. 7 illustrates an example of a compensation procedure for synchronizing image processing delay and audio processing delay in a Bluetooth low-latency audio system proposed in this specification.

[0270] Video and audio signals each have their own unique delays as they pass through various stages of decoding, processing, and output. This delay difference can cause misalignment between video and audio, making it essential to synchronize the two for a natural audiovisual experience.

[0271] The video processing path involves compressed data being decoded, then undergoing image enhancement and display output. This process can include various processes such as frame doubling, anti-aliasing, and TCON (Timing Controller), which, as shown in the diagram, can result in a relatively large delay of approximately 100 ms or more. This is the result of a combination of the physical delay required to display the image on screen and the processing delay.

[0272] The audio processing path involves decoding compressed audio data, then going through the Bluetooth encoding / transmission / decoding process, and possibly applying additional audio enhancements. This includes various audio-related processes such as buffering, pop filtering, woofer boost, and active noise cancellation. These processes introduce delays into the audio signal, and the diagram shows this audio processing delay at approximately 30ms or more. This delay is relatively short compared to video delay.

[0273] There is a significant difference between video processing delay and audio processing delay. The compensation procedure presented in Figure 7 aims to overcome this delay difference and synchronize video and audio. It utilizes information such as the Presentation Time Stamp (PTS) to determine the original timing of the video and audio data, intentionally delaying the output of the audio signal with a shorter delay or making other timing adjustments to ensure that the video and audio are output nearly simultaneously.

[0274] FIG. 8 illustrates an example of a test stream-based calibration procedure for measuring and adjusting the sound pressure level of each speaker based on a user position in a BLE-based audio system proposed in this specification.

[0275] Figure 8 illustrates an example of a test stream-based calibration procedure for measuring and adjusting the sound pressure level (SPL) from each speaker relative to the user's listening position (sweet spot) in a Bluetooth low-latency audio system. This process aims to optimize balanced sound from each speaker in a multi-speaker audio system at the user's primary seating position. This procedure utilizes a measurement device, such as a smartphone, to achieve this goal.

[0276] The calibration process begins with playing a test audio stream to each speaker. As shown in the figure, the user's smartphone or control device individually sends a command to play the test stream to each speaker. Each speaker then plays its own corresponding test sound via a unicast connection. This test stream may be a signal with a specific frequency range or characteristics designed for loudness measurement.

[0277] While the test stream plays through each speaker, the user measures the sound pressure level (SPL) arriving at each speaker using a sound pressure measurement device, such as a smartphone, at their primary listening position (the "Sweet Spot"). The figure shows the user sitting in the center, holding the smartphone, and measuring the SPL values ​​coming from each speaker. The measured SPL values ​​for each speaker position may vary depending on factors such as the distance from the speaker, the speaker's performance, and the surrounding environment (e.g., SPL=60, SPL=80, SPL=30).

[0278] Based on the measured sound pressure level of each speaker, the system adjusts the final audio output. By adjusting the volume or gain of each speaker to compensate for differences in measured SPL values, the system ensures that all speakers sound at the intended relative loudness when the user is listening in the "Sweet Spot." This process compensates for volume differences caused by individual speaker locations or characteristics, and optimizes the overall sound field of the multichannel audio system to the user's location, providing a more immersive sound experience.

[0279] FIG. 9 illustrates an example of an inter-speaker synchronization correction structure for correcting sound synchronization error due to a difference in distance between a TV speaker and a rear speaker in a multi-channel audio system proposed in this specification.

[0280] FIG. 10 illustrates an example of a speaker-to-speaker synchronization structure for compensating for sound synchronization errors due to distance differences between rear speakers in a multi-channel audio system proposed in this specification.

[0281] Figures 9 and 10 illustrate various examples of inter-speaker synchronization structures for compensating for acoustic synchronization errors caused by distance differences between multiple speakers and the user's listening position in a multichannel audio system. Since sound propagates through the air at a finite speed, if each speaker is located at a different distance from the listener, the time it takes for the sound to reach the listening position also varies. This difference in sound arrival times can distort the accurate spatial perception and sound image localization of multichannel sound.

[0282] Figure 9 illustrates the effect of the distance difference between the TV speakers (which typically serve as front speakers) and the rear speakers on audio synchronization. Figure 9 shows that the rear speakers are located further away from the listener than the TV speakers (e.g., 3 meters), causing sound from the rear speakers to arrive at the listening position later than sound from the TV speakers. Even though the system transmits audio signals simultaneously, the listener experiences a temporal mismatch due to the physical distance difference.

[0283] Figure 10 illustrates the effect of distance differences between rear speakers on synchronization. The left and right rear speakers may not be positioned exactly the same distance from the listener, and the figure assumes one rear speaker is slightly further away than the other (e.g., a distance difference of 3 meters). Even these slight distance differences between speakers can cause sound arrival times to vary, and especially in sophisticated surround sound environments, these errors can lead to distortion of the sound image.

[0284] To compensate for this audio synchronization error caused by distance differences, the system measures the distance between each speaker and the listening position or calculates the difference in sound arrival times based on a preset value. The system then performs compensation by intentionally delaying the audio signal output from speakers closer to the listening position by the calculated difference. In other words, by adjusting the timing of sound from all speakers to arrive at the listening position, the system ensures that even in multichannel systems with speakers in different locations, users experience a precise and consistent soundstage as designed.

[0285] FIG. 11 is a diagram illustrating the roles of devices defined for audio broadcasting to which the method proposed in this specification can be applied.

[0286] Referring to Figure 11, a transmitter (e.g., Auracast) TM Transmitter) can include television, laptop, PA system, etc. Assistant (e.g. Auracast TM The Assistant may include a smartphone, a smart watch, a hearing aid remote, etc. The Receiver (e.g., Auracast) TM Receiver) may include headphones, earbuds, hearing aids, etc.

[0287] Auracast TM Auracast is a Bluetooth-based broadcast audio transmission technology, consisting of a transmitter, a receiver, and an assistant, each with a clear role and defined by its standard. Below is Auracast TMDescribes the role of each component and the specific specifications that support it.

[0288] [1] Auracast TM Transmitter

[0289] Auracast TM The Transmitter performs the following roles:

[0290] Broadcast Source

[0291] Public Broadcast Source

[0292] Initiator

[0293] Broadcast Media Sender

[0294] The role is defined in the specification below:

[0295] BAP (Basic Audio Profile), Section 2.2.2.1

[0296] PBP (Public Broadcast Profile), Section 3.1

[0297] CAP (Common Audio Profile), Section 2.1.1

[0298] TMAP (Telephony and Media Audio Profile), Section 3.5.2

[0299] [2] Auracast TM Receiver

[0300] Auracast TM The Receiver has the following roles:

[0301] Broadcast Sink

[0302] Public Broadcast Sink

[0303] Acceptor

[0304] Hearing Aid

[0305] Broadcast Media Receiver

[0306] The role is defined based on the following specifications:

[0307] BAP, Section 2.2.2.2

[0308] PBP, Section 3.2

[0309] CAP, Section 2.1.2

[0310] HAP (Hearing Access Profile), Section 3.2

[0311] TMAP, Section 3.5.2

[0312] [3] Auracast TM Assistant

[0313] Auracast TM The Assistant performs the following roles:

[0314] Broadcast Assistant

[0315] Public Broadcast Assistant

[0316] Commander

[0317] This role is defined in the following specification:

[0318] BAP, Section 2.2.2.3

[0319] PBP, Section 3.3

[0320] CAP, Section 2.1.3

[0321] In this way, each component performs multiple roles and is defined across various Bluetooth standards. For example, the embodiments of this specification described below may be based on the role structure described above. A specific example is Auracast. TM The embodiments of this specification described below may be applied to efficiently perform operation procedures and functions within an environment.

[0322] FIG. 12 is a diagram illustrating key elements of an audio broadcast assistant to which the method proposed in this specification can be applied.

[0323] Referring to FIG. 12, an audio broadcast assistant (e.g., Auracast) to which the method proposed in the present invention can be applied TM Assistant) may include the following key features:

[0324] Audio Stream Information Input

[0325] Audio stream information is fed to the Audio Broadcast Assistant from the audio transmitter or network. This identifies available broadcast streams or provides reference information for subsequent processing.

[0326] [1] The Audio Broadcast Assistant can scan / search for broadcast streams in the surroundings. The Audio Broadcast Assistant can forward the discovered broadcast streams to other devices through scan delegation.

[0327] [2] The Audio Broadcast Assistant can perform Display, Selection, and Control of Broadcast streams.

[0328] [3] The Audio Broadcast Assistant can support Coordinated Sets (e.g., groups that make up a surround sound system).

[0329] [4] The Audio Broadcast Assistant can input / set a Broadcast_Code to the sink (speaker). The Broadcast_Code is used to access a specific broadcast (e.g., an encrypted Broadcast Isochronous Stream (BIS)).

[0330] The Audio Broadcast Assistant broadcasts audio to one or more receivers (e.g., Auracast) via an Asynchronous Connection-Less (ACL) link. TM You can control the Receiver.

[0331] As described above, the main functions of the Audio Broadcast Assistant enable efficient search, selection, control and receiver control of audio broadcast streams.

[0332] FIG. 13 is a diagram illustrating profiles and services used by an audio broadcast assistant to which the method proposed in this specification can be applied.

[0333] An audio broadcast assistant according to an embodiment of the present disclosure can perform advanced broadcast audio control functions by utilizing various layers of profiles and services based on the Bluetooth audio technology stack. The following diagram illustrates the hierarchical structure of Bluetooth technology components used by the audio broadcast assistant.

[0334] 1. Bluetooth Core Specification 5.2 or higher

[0335] This specification is based on Bluetooth Core Specification 5.2 and later and supports new features related to LE Audio. This layer handles low-level operations such as basic connection, pairing, and communication.

[0336] 2. LC3 (Low Complexity Communication Codec)

[0337] A high-efficiency codec for audio compression, supporting low latency and high-quality transmission. In this specification, Auracast is implemented using the LC3 codec. TM Process audio streams efficiently.

[0338] 3. Generic Audio Framework (GAF)

[0339] ① CAP (Common Audio Profile)

[0340] A top profile that manages various audio functions in common

[0341] The Audio Broadcast Assistant provides integrated control of connectivity and functionality between transmitters and receivers via CAP.

[0342] ② CAS (Common Audio Service)

[0343] A service-level component corresponding to CAP, which performs actual audio session control and attribute management.

[0344] 4. Service and Profile Layer

[0345] ① BAP (Basic Audio Profile)

[0346] Basic broadcast audio processing

[0347] ② PACS, ASCS, BASS

[0348] Detailed services for audio transmission channels and broadcast support

[0349] In particular, BASS (Broadcast Audio Scan Service) plays a key role in the scanning and control functions of the Audio Broadcast Assistant.

[0350] ③ Other related services (gray blocks):

[0351] MCP (Media Control Profile), MCS (Media Control Service), VCP (Volume Control Profile), CSIP, TBS, CCP, etc.

[0352] These configure additional functions such as volume control, media playback, call control, etc. and can be integrated into the audio broadcast assistant function as needed.

[0353] 5. Use Case Specific Profiles

[0354] TMAP (Telephone / Media Audio Profile), HAP (Hearing Aid Access Profile), HAS (Hearing Aid Services), PBP (Public Broadcast Profile), etc.

[0355] An audio broadcast assistant according to an embodiment of the present specification can be designed / implemented to support various user scenarios (e.g., hearing aid, media viewing, public place audio reception, etc.) based on these profiles.

[0356] FIG. 14 is a diagram illustrating an audio broadcast assistant application to which the method proposed in this specification can be applied.

[0357] FIG. 15 is a diagram illustrating roles defined for audio broadcast / unicast to which the method proposed in this specification can be applied.

[0358] The audio system according to the embodiments of this specification can provide broadcast and unicast audio services through the cooperation of various devices based on the Basic Audio Profile (BAP) and the Common Audio Profile (CAP). Figure 15 illustrates the role of each component and the structure of the data flow (Control / Audio) between them. The roles are described in detail below with reference to Figure 15.

[0359] Transmitter-side configuration (user and microphone device)

[0360] The BAP Broadcast Source, CAP Initiator, and Microphone device can perform the following roles:

[0361] BAP Broadcast Assistant: Helps you find and connect to broadcast streams.

[0362] CAP Commander: CAP-based control signal transmission

[0363] Volume Controller: Receiver volume control function

[0364] Microphone Controller: Controls microphone input

[0365] A smartphone or central control unit transmits control information and audio streams to peripheral devices.

[0366] Receiver side configuration (Ambient devices such as hearing aids)

[0367] Devices in the Ambient area perform the following roles:

[0368] BAP Broadcast Sink: Receives broadcast audio

[0369] BAP Scan Delegator: Scans surrounding broadcast streams.

[0370] BAP Unicast Server: Acts as a unicast audio transmission server.

[0371] CAP Acceptor: Accepts CAP-based session reception and setup.

[0372] Volume Renderer: Reflects received volume control commands into actual sound levels.

[0373] Media Control Client: Receives commands such as play / stop media.

[0374] BAP Unicast Client: Unicast audio client

[0375] CAP Initiator: Initiates a connection and initiates communication with a microphone or control device.

[0376] Below we describe the volume renderer, volume controller, and initiator source in detail.

[0377] A Volume Renderer (VR) is a device that receives one or more audio inputs and controls the audio output. A Volume Renderer has all inputs and outputs. It has all the information, use case information, and use case intelligence. It determines how to adjust the volume. A Volume Renderer can include earphones, hearing aids, loudspeakers, and CAP acceptors.

[0378] A volume controller (VC) is a device that controls the volume and related state of audio. A volume controller may not have all the information it needs. It may only have a limited amount of information. It does not have use-case information. It requests adjustments and determines when and to what volume to adjust. Volume controllers can include PCs, mobile phones, tablets, and CAP commanders.

[0379] The Initiator Source holds information and knowledge about all audio provided by the stream. It provides context type, mixed audio information, and more.

[0380] The Volume Control Service (VCS) is a GATT-based service that reports or controls the volume status of BLE devices (e.g., speakers, hearing aids, etc.). VCS can include a volume state, a volume control point, and volume flags.

[0381] FIG. 16 illustrates an example of an overall system configuration for multi-channel audio transmission between a BLE-based TV and multiple audio receiving devices proposed in this specification and a profile structure based on Surround Sound Audio Profile (SSAP).

[0382] The system of Fig. 16 is structured such that a TV, which is a source device, acts as an LE Audio transmitter (Tx), multiple speakers act as LE Audio receivers (Rx), and a TV or phone acts as a control assistant, wirelessly transmitting multi-channel audio via BLE. Fig. 16 details the relationship between each component and profile / service, from the application / host software to the physical layer.

[0383] Settings related to App / Host S / W may include User / Phone, Speaker location based sweet-spot calibration.

[0384] Settings related to Audio+middleware may include Volume Level Calibration / Control, Sync ((1) Inter-Speaker (2) TV - Speaker), Codec (LC3).

[0385] Settings related to the Core (PHY / MAC) may include Iso CH Broadcast settings. For example, LE isochronous channel settings for SSAP may include ISO parameters, SDU interval, ISO interval, NSE(=BN), FT, total net bit rate, etc.

[0386] On the TV transmitter side, the audio signal is processed by the multi-channel audio processor, then converted into a format suitable for BLE transmission through the multi-CH LC3 encoding process. The encoded audio data is transmitted to the LE ISO CH (Isochronous Channel) layer via the I2S interface, where LE Isochronous Channels are configured to broadcast multi-channel audio streams in a synchronized form. Finally, it is wirelessly transmitted to the speakers through the BLE Tx PHY / MAC layer, demonstrating that the data transmission rate can range from 2 Mbps to a maximum of 8 Mbps.

[0387] On the control assistant device side (TV or phone), connection to speakers and parameter setting for those speakers can be performed via LE ACL link.

[0388] On the speaker receiving device side, LE ISO CH broadcast data transmitted through BLE Tx / Rx PHY / MAC layers is received. The received data passes through the LE ISO CH layer and is restored to the original multi-channel audio signal through the Multi-CH LC3 audio decoding process. The decoded audio signal is output as sound through the speaker driver. Each speaker receives and plays the audio data of the channel it is responsible for, thereby implementing multi-channel sound. On the speaker side, there are upper layers such as LE Audio Profiles, Sync, and SSAP, which are responsible for interaction and control with the TV.

[0389] In the system of Fig. 16, the Surround Sound Audio Profile (SSAP) and the BLE Audio profiles that form its basis play a crucial role. The Broadcast Audio Profile (BAP) defines the basic functions of audio broadcasting, the Published Audio Capabilities (PAC) provide audio-related capability information including codecs and speaker capabilities, and the Audio Stream Control (ASC) manages audio stream control, QoS, positioning, delay, etc. SSAP can be viewed as a higher-level profile structure that utilizes these sub-profiles to define and control speaker configuration, role assignment, synchronization, etc. required for specific multi-channel audio scenarios such as surround sound.

[0390] As examples of SSAP device roles, a TV or mobile phone can act as a control assistant. The TV can act as a source for broadcast audio. Four speakers can act as sinks, receiving audio and reporting status and functionality.

[0391] Table 2 below illustrates Surround Sound Audio Profile (SSAP) Functions that can be applied to the embodiments proposed in this specification.

[0392]

[0393] Figure 17 is a drawing illustrating the scope and purpose of the SSAP proposed in this specification.

[0394] Specifically, Figure 17 illustrates a structure showing where the Surround Sound Audio Profile (SSAP) is located within the Bluetooth audio standard ecosystem and what it is associated with.

[0395] Referring to Figure 17, SSAP is a new use case profile within the Bluetooth audio architecture, defined alongside existing profiles such as TMAP and GMAP. SSAP is designed as a standard to provide a high-quality surround audio experience by working in conjunction with elements such as the LC3 Codec, GAF (BAP), and Core Spec (CIS / BIS, HDT). The scope of SSAP clearly defines the scenarios to which the profile applies, and its purpose is to enable immersive surround sound delivery even in a Bluetooth environment.

[0396] FIG. 18 is an example of multi-channel transmission using SSAP according to an embodiment of the present specification.

[0397] Referring to Figure 18, the TV acts as an SSAP Source. The TV or phone (app) acts as an SSAP Control Assistant. The SSAP Control Assistant can perform the search / status / support function determination of a sink speaker device (a speaker supporting SSAP) that supports SSAP multichannel audio. For example, the search / status / support function of a speaker supporting SSAP can be determined through an LE ACL link or LE Advertising.

[0398] FIG. 19 is another example of multi-channel transmission using SSAP according to an embodiment of the present specification.

[0399] Referring to Fig. 19, a sound bar connected to a TV or phone via an HDMI (High-Definition Multimedia Interface) cable, an optical cable, or Bluetooth (BT) acts as an SSAP source. The phone (app) acts as an SSAP control assistant. In this case, the SSAP control assistant (phone) can search for / detect the status / support functions of a sink speaker device (speaker supporting SSAP) that supports SSAP multichannel audio, and then transmit the relevant information to the TV / sound bar.

[0400] Hereinafter, with reference to FIGS. 20 to 23b, a multi-channel audio connection control operation between a BLE-based TV and multiple speakers using a Control Assistant (e.g., SSAP assistant) is specifically described.

[0401] FIG. 20 is a diagram illustrating a multi-channel audio connection control operation using a control assistant according to an embodiment of the present specification.

[0402] Referring to FIG. 20, a TV or soundbar (Source) is connected to multiple sink speakers for BLE Multi Channel Audio (SSAP). According to an embodiment of the present disclosure, a control assistant device (e.g., a phone, TV, tablet) searches for and configures nearby sink speakers. The operation of the control assistant device is described in detail below.

[0403] 1) [Sink Discovery]: Sink speakers transmit their status and functionality information via BLE advertisements (ADV_IND). These BLE advertisements may include supported ISO channel parameters, speaker location, codec configuration information, etc.

[0404] 2) [Sink Discovery]: The SSAP Control Assistant scans the BLE advertisements of surrounding Sink devices.

[0405] 3) [Source / Sink Configuration]: The SSAP Control Assistant checks the status of each device: supported ISO channel parameters, speaker locations, codec configuration information, etc.

[0406] 4) [Source / Sink Configuration]: The SSAP control assistant configures BLE link parameters, codec, volume, and presentation_delay settings for multi-channel audio transmission.

[0407] 5) [Source / Sink Re-configuration]: The source reconfigures the ISO channel count, volume, and synchronization parameters of the Sink speakers.

[0408] 6) [Broadcast Audio]: The source broadcasts audio with the newly configured settings.

[0409] For example, a TV can act as an SSAP Control Assistant and determine the search, status, and support functions of a multi-channel audio-capable Sink speaker device. For example, a phone can act as an SSAP Control Assistant and determine the search, status, and support functions of a multi-channel audio-capable Sink speaker device, and then pass these information on to the Source TV / soundbar.

[0410] The SSAP Control Assistant can set parameters related to at least one of the following 1) to 4) for the speakers.

[0411] 1) Broadcast settings (e.g. Broadcast streams, BIS number, BIG number, coordinated set (member within group),

[0412] 2) Broadcast Code,

[0413] 3) Volume settings (e.g. common global for all speakers, individual gain for each speaker (FL, FR, RL, RR))

[0414] 4) Set a delay (e.g. presentation_delay)

[0415] FIG. 21 is a diagram illustrating a multi-channel audio connection control operation using a control assistant according to an embodiment of the present specification at time intervals.

[0416] Specifically, Fig. 21 shows the operations 1) to 6) described in Fig. 20 by time interval.

[0417] [Sink Discovery)]: By scanning the BLE advertisements of Sinks #1~4, the SSAP control assistant determines the status of Sinks #1~4.

[0418] [Source / Sink Configuration]: The SSAP Control Assistant configures parameters for Sinks #1-4. These parameters may include parameters related to at least one of: 1) broadcast configuration (e.g., Broadcast streams, number of BIS, BIG number, coordinated set (member within group), 2) broadcast code, 3) volume configuration, and / or 4) delay configuration (e.g., presentation_delay).

[0419] [Broadcast Audio]: The Source initiates a 4CH Broadcast. Specifically, the Source transmits BIS for each Sink (FL, FR, RL, RR) at each sub-interval within the ISO interval.

[0420] [Sink Report]: The status (off) of Sink#4 is reported to the Source.

[0421] [Source / Sink Reconfiguration]: The Source performs a Sink reconfiguration (4CH(RL, FR, RL, RR) -> 3CH(RL, FR, RL)). Specifically, the Source reconfigures a group (e.g., a BIG, coordinated set, or a group in a surround sound system) excluding Sink#4 (RR).

[0422] [Broadcast Audio]: Source starts a 3CH Broadcast based on the newly configured settings.

[0423] FIG. 22 is a diagram showing the role of a conventional broadcast assistant and the role of a broadcast assistant according to an embodiment of the present specification.

[0424] Referring to FIG. 22, a Control Assistant Device (e.g., Phone, TV, Tablet) can extend the broadcast support role defined in LE Audio to configure sink speakers.

[0425] 22A of Fig. 22 illustrates the role of a conventional broadcast assistant. 22A of Fig. 22 is identical to Fig. 12 described above, and thus redundant descriptions are omitted.

[0426] Referring to FIG. 22B, compared to the role of a conventional broadcast assistant, a broadcast assistant according to an embodiment of the present disclosure can additionally set the volume and audio delay (e.g., Audio_delay or presentation_delay) of a sync speaker.

[0427] 22C of FIG. 22 illustrates parameters set for a sink (speaker) by a broadcast assistant according to an embodiment of the present disclosure. Specifically, compared to 22A of FIG. 22, the broadcast assistant according to an embodiment of the present disclosure may additionally set volume configurations and audio delays (e.g., Audio_delay or presentation_delay).

[0428] FIG. 23a is a diagram illustrating a multi-channel audio connection control operation between a BLE-based TV and multiple speakers using a control assistant according to an embodiment of the present specification. FIG. 23b is a diagram illustrating an LE ACL / Advertising-related payload for a multi-channel audio connection control operation between a BLE-based TV and multiple speakers using a control assistant according to an embodiment of the present specification.

[0429] In Figures 23a and 23b, the device roles are as follows.

[0430] The TV or phone acts as a control assistant.

[0431] The TV acts as a source for broadcast audio.

[0432] Four speakers (FL, FR, RL, RR) operate as a synchronizer to perform audio reception, status and function reporting.

[0433] The time interval operations in Fig. 23a and Fig. 23b are as follows.

[0434] 1) Sink Discovery: The sink speaker transmits a BLE advertisement (ADV_IND) to inform its status and capabilities. The BLE advertisement may include supported ISO CH parameters, speaker position, and codec configuration of the speaker. The SSAP Control Assistant (TV, Phone) operates in scan mode. Specifically, the SSAP Control Assistant scans for BLE advertisements from nearby sink devices. Referring to Fig. 23b, the payload associated with the LE Advertisement transmitted by each speaker (e.g., the payload of the ADV_IND Packet) may include i) header, ii) Volume Delta, iii) Presentation_delay, iv) sync_offset, and v) power (battery status). The SSAP Control Assistant checks the status of each device (e.g., supported ISO CH parameters, speaker position, and codec configuration).

[0435] 2) Sink configuration: Referring to Figure 23b, when speakers are connected to a source via an LE ACL link, the SSAP Control Assistant / source can determine / verify the capabilities of each speaker (e.g., additional capabilities beyond those indicated via advertising). The SSAP Control Assistant configures the BLE link parameters, codec, volume, and multi-channel audio synchronization (presentation_delay) for the speakers.

[0436] 3) The source starts a 4CH broadcast.

[0437] 4) Sink Report: Referring to FIG. 23b, for example, a status report of a specific sink speaker may be transmitted to the source based on an LE ACL. For example, each speaker may transmit a status report to the source based on LE advertising.

[0438] 5) Sink Reconfiguration: The source can perform a sink reconfiguration based on a status report. Specifically, the source can reconfigure the sink speaker's ISO channel count and volume / synchronization parameters. The source then begins broadcasting based on the new settings (e.g., 3CH).

[0439] Hereinafter, a technology for controlling volume, audio quality, and transmission quality by utilizing the exchange of power status information between a TV and speakers is described with reference to FIGS. 24 to 29.

[0440] According to an embodiment of the present specification, the Source transmits audio based on the ISO CH, and the Sink transmits status (volume, sync, power status, etc.) to the Source based on the control CH (LE ACL or LE Advertising). This allows the Source to update the volume, sync, and CH. The above-described operation is described with reference to FIGS. 24 to 26.

[0441] FIG. 24 is a diagram illustrating a situation in which the battery of a specific speaker is very low in a multi-channel transmission operation according to an embodiment of the present disclosure. FIG. 25 is a diagram illustrating an operation according to a conventional method in a situation in which the battery of a specific speaker is very low in a multi-channel transmission operation. FIG. 26 is a diagram illustrating an operation according to an embodiment of the present disclosure in a situation in which the battery of a specific speaker is very low in a multi-channel transmission operation.

[0442] Referring to Figure 24, the battery status of the third speaker (RL) among the four speakers is 90%, and the battery status of the fourth speaker (RR) is 1%.

[0443] In this state, the operation according to the existing method is as shown in Fig. 25.

[0444] Referring to FIG. 25, the fourth speaker (CH#4: RR) is powered off due to a discharged battery, and this ISO CH packet is not received by the speaker. However, in the conventional broadcast mode, the source cannot receive the status (volume, synchronization, power status) of the sink. For example, even if the sink is powered off due to a low battery and cannot receive broadcast audio from the sink, the source cannot know whether the sink is receiving the broadcast audio. On the other hand, the operation according to the embodiment of the present specification can be performed as shown in FIG. 26.

[0445] Referring to Fig. 26, based on the LE ACL connection for volume control, an individual Sink (Sink #4) transmits its status (volume, Sync, Power Status, etc.) to the Source. For this purpose, an LE ACL packet transmission interval is allocated after an LE Audio packet transmission interval within the ISO Interval. Based on the status of the Sink, the Source updates the Sink configuration. For example, the Source updates the number of ISO CHs and the Volume / Sync control per speaker by reflecting the status of multiple Sinks. As a specific example, after Sink #4 is turned off, the Source updates the broadcast settings by changing the number of audio channels from 4 to 3. The Source then starts a broadcast based on the new CH (3 CH).

[0446] FIG. 27 is a diagram showing an example of a CH change operation due to removal of a specific speaker during a 4 CH broadcast operation for 4 speakers according to an embodiment of the present specification.

[0447] Specifically, FIG. 27 illustrates an embodiment 1 of a CH change operation due to speaker removal (e.g., battery out) in a Broadcast for 4 speakers (transmitted to 4 BIS within 1 BIG). The CH change operation will be described in detail below with reference to FIG. 27.

[0448] 1) Based on the LE ACL connection for Sink status report, individual Sinks (e.g. Speaker 4) report their status (volume, sync, power status, etc.) to the Source. For this purpose, an LE ACL packet transmission interval is allocated after the LE Audio packet transmission interval within the ISO Interval.

[0449] 2) The Source updates the ISO CH count and the Volume / Sync control for each speaker to reflect the status of multiple Sinks. Specifically, since the battery status of Speaker 4 (RR) is 1%, the Source changes the ISO CH count from 4 to 3.

[0450] 3) The source device starts broadcasting based on the new CHs (transmitting 3 BIS).

[0451] FIG. 28 is a diagram showing another example of a CH change operation due to removal of a specific speaker during a 4 CH broadcast operation for 4 speakers according to an embodiment of the present specification.

[0452] Specifically, Fig. 28 illustrates Example 2 of a CH change operation due to speaker removal (e.g., Battery out) in a Broadcast for 4 speakers (transmitted to 4 BIS within 1 BIG).

[0453] Referring to Fig. 28, Sinks (Speakers 1 to 4) transmit their status (volume, sync, power status, etc.) to the Source based on LE Advertising for Sink status report. For this purpose, a post-LE Advertising packet transmission period is allocated within the ISO Interval, and the Source (TV) operates in scan mode during the LE Advertising packet transmission period. Since the subsequent operations are the same as in Fig. 27, duplicate descriptions are omitted.

[0454] Below, a technique for changing broadcast channel settings using periodic broadcast and response is described with reference to FIG. 29.

[0455] In one embodiment, an operation may be considered to use periodic BLE Broadcast and Response to determine the status of multiple speakers and then change to an optimal Broadcast channel setting.

[0456] The status of multiple speakers can be identified by applying Periodic Advertising with Response (PAwR) or ISO CH.

[0457] For example, sinks (speaker cells) can transmit channel status (e.g. Packet Error Rate, Channel Status (Good / Poor), Volume, Sync, Power Status, etc.) responses within the periodic broadcast interval of a control device (TV, Sound Bar).

[0458] For example, a control device (Broadcaster) can, when necessary, issue an LE ACL connection request (AUX_ CONNECT_REQ) to a specific device (sink, speaker). The interval between the Broadcast and Response cycles can be adjusted depending on the number of devices and their settings.

[0459] FIG. 29 is a diagram illustrating an operation of changing channel settings by utilizing periodic BLE broadcast and response according to an embodiment of the present specification.

[0460] Specifically, Figure 29 illustrates an embodiment in which a Sink transmits status (volume, Sync, Power Status, etc.) to a Source through a periodic Response.

[0461] A source (TV or Sound Bar) transmits an 8CH broadcast (BIS 1-8). Specifically, the source transmits a BIS for each of the 8 speakers based on Broadcast Slots at each periodic advertising subevent interval (e.g., PAwR Subevent#0, PAwR Subevent#1, etc.).

[0462] Each speaker (Speaker 1-8) transmits a response to the source based on the sink response slots. The spacing of each slot can be defined as the periodic advertising response slot spacing. The response of Speaker 1 indicates the state of Speaker 1 (Volume Delta=+3, Presentation_delay=20ms, Sync_offset=-50us, Location=FR, Power=1%).

[0463] The source can reconfigure the group (e.g., a group or coordinated set in a surround sound system) based on the state of speaker 1 (Power = 1%), excluding speaker 1 (Spk1~8 -> Spk2~8). The source can initiate a broadcast by changing channel 8 to channel 7 (transmitting BIS 1~7).

[0464] The embodiments described below are specifically described with reference to FIG. 30 in terms of the operation of a source (e.g., a TV device). The methods described below are distinguished for convenience of explanation, and it is understood that some components of one method may be substituted for some components of another method, or may be applied in combination with each other, as long as they are not mutually exclusive.

[0465] FIG. 30 is a flowchart illustrating a method performed by a source according to one embodiment of the present specification.

[0466] According to various embodiments of the present specification, a method is provided that is performed by a source such as a TV that supports a short-range communication system such as Bluetooth.

[0467] The source includes a first processor corresponding to a host stack; a second processor corresponding to a first controller stack; a memory; and a transceiver. The host stack and the controller stack are connected via a Host Controller Interface (HCI).

[0468] In S3010, the source scans advertisements for speakers associated with a surround sound system. For example, each advertisement includes information indicating whether each speaker supports a Surround Sound Audio Profile (SSAP). For example, each advertisement may include information indicating the availability of each speaker. For example, each advertisement may include information indicating the capabilities of each speaker. S3010 may be based on the sink discovery operation described above (Figs. 21, 23a, and 23b).

[0469] In the S3020, the source is connected to the above speakers.

[0470] In S3030, the source transmits information including at least one parameter to each of the speakers. For example, S3020 and S3030 may be based on the Source / Sink Configuration operation described above. For example, the information including at least one parameter may be based on a setting by the control assistant described above (Figs. 21, 22, 23a, and 23b).

[0471] In one embodiment, the at least one parameter may include a volume control parameter. For example, the volume control parameter may include information based on settings by the control assistant described above (22C of FIG. 22, Volume_Configurations). As a specific example, the volume control parameter may include i) a parameter related to a common global gain for the speakers and / or ii) a parameter related to an individual gain for each of the speakers.

[0472] In one embodiment, the source may include a TV, a sound bar, or a smart phone defined to act as a SSAP assistant that manages discovery and grouping of nearby speakers.

[0473] In one embodiment, the speakers connected to the source may belong to a group associated with the surround sound system.

[0474] In one embodiment, the method may further include a group reconfiguration step. Specifically, the source may reset / reconfigure the group by excluding specific speakers from the speakers. The group reconfiguration may be performed based on status information received based on an LE ACL link or LE Advertising. This will be described in detail below.

[0475] In one embodiment, the method may further include receiving status information from the specific speaker. Specifically, the source may receive status information from the specific speaker based on an LE ACL link. The group may be reset based on the status information. For example, the status information may include at least one of i) volume delta, ii) presentation delay, iii) sync offset, iv) location, and / or v) battery.

[0476] In one embodiment, the method may further include the step of receiving periodic advertisements. Specifically, the source may receive periodic advertisements from the speakers. In other words, the source may scan the periodic advertisements of the speakers (the Scan Mode operation described above). The group may be reconfigured based on the periodic advertisements. For example, each of the periodic advertisements may include status information of each speaker. The status information may include at least one of i) volume delta, ii) presentation delay, iii) sync offset, iv) location, and / or v) battery.

[0477] In one embodiment, the information including the at least one parameter may be transmitted based on a Low Energy Asynchronous Connection-Less (LE ACL) link.

[0478] In one embodiment, the at least one parameter may further include at least one of: i) a parameter related to a broadcast code, ii) a parameter related to a broadcast configuration, and / or iii) a parameter related to a presentation delay.

[0479] In one embodiment, an audio signal for each of the speakers may be transmitted based on an LE ISO (Low Energy Isochronous) channel. For example, if the source described above is a TV operating as a SSAP assistant, the source may transmit an audio signal for each of the speakers based on an LE ISO channel. For example, if the source described above is a smart phone operating as a SSAP assistant, a broadcast audio source (e.g., a TV, a sound bar) may transmit an audio signal for each of the speakers based on an LE ISO channel.

[0480] For example, the audio signal may be based on a Broadcast Isochronous Stream (BIS).

[0481] For example, the BIS for each of the speakers may be transmitted within an ISO sub interval.

[0482] In one embodiment, the channels associated with the speakers may include at least one of i) a Front Left (FL) channel, ii) a Front Right (FR) channel, iii) a Rear Left (RL) channel, and / or iv) a Rear Right (RR) channel.

[0483] According to various embodiments of the present disclosure, a control device for controlling a source is provided. The control device includes at least one processor and at least one memory operably connected to the at least one processor. The at least one memory may be configured to store instructions for performing a method of operating a source according to FIG. 30 based on execution by the at least one processor.

[0484] According to various embodiments of the present disclosure, one or more non-transitory computer-readable media (CRM) storing one or more instructions are provided. The one or more instructions, when executed by one or more processors, perform operations, and the operations may include a method of operating a source according to FIG. 30.

[0485] The embodiments described below are specifically described with reference to FIG. 31 in terms of speaker operation. The methods described below are distinguished for convenience of explanation, and it is understood that some components of one method may be substituted for or combined with some components of another method, as long as they are not mutually exclusive.

[0486] FIG. 31 is a flowchart illustrating a method performed by a speaker according to another embodiment of the present specification.

[0487] According to various embodiments of the present specification, a method is provided that is performed by a speaker supporting a short-range communication system such as Bluetooth.

[0488] The speaker includes a third processor corresponding to a host stack; a fourth processor corresponding to a third controller stack; memory; and a transceiver. The host stack and the controller stack are connected via a Host Controller Interface (HCI).

[0489] In S3110, the speaker transmits an advertisement to the source. For example, the advertisement includes information indicating whether the speaker supports a Surround Sound Audio Profile (SSAP). For example, the advertisement may include information indicating the availability of the speaker. For example, the advertisement may include information indicating the capabilities of the speaker. S3110 may be based on the sink discovery operation described above (FIGS. 21, 23A, and 23B).

[0490] In the S3120, the speaker is connected to the above source.

[0491] In S3130, the speaker receives information including at least one parameter from the source. For example, S3120 and S3130 may be based on the Source / Sink Configuration operation described above. For example, the information including at least one parameter may be based on a setting by the control assistant described above (FIGS. 21, 22, 23a, and 23b).

[0492] In one embodiment, the at least one parameter may include a volume control parameter. For example, the volume control parameter may include information based on settings by the control assistant described above (22C of FIG. 22, Volume_Configurations). As a specific example, the volume control parameter may include i) a parameter related to a common global gain for the speakers and / or ii) a parameter related to an individual gain for each of the speakers.

[0493] In one embodiment, the source may include a TV, a sound bar, or a smart phone defined to act as a SSAP assistant that manages discovery and grouping of nearby speakers.

[0494] In one embodiment, the speaker connected to the source may belong to a group associated with a surround sound system.

[0495] In one embodiment, group reconfiguration may be performed by the source. Specifically, the source may reset / reconfigure the group by excluding the speaker from the speakers. The group reconfiguration may be performed based on status information received based on an LE ACL link or LE Advertising. This will be described in detail below.

[0496] In one embodiment, the method may further include a step of transmitting status information to the source. Specifically, the speaker may transmit the status information to the source based on an LE ACL link. The group may be reset based on the status information. For example, the status information may include at least one of i) volume delta, ii) presentation delay, iii) sync offset, iv) location, and / or v) battery.

[0497] In one embodiment, the method may further include the step of transmitting a periodic advertisement. Specifically, the speaker may transmit a periodic advertisement to the source. The group may be reset based on the periodic advertisement. For example, the periodic advertisement may include status information of the speaker. The status information may include at least one of i) volume delta, ii) presentation delay, iii) sync offset, iv) location, and / or v) battery.

[0498] In one embodiment, the information including the at least one parameter may be received based on a Low Energy Asynchronous Connection-Less (LE ACL) link.

[0499] In one embodiment, the at least one parameter may further include at least one of: i) a parameter related to a broadcast code, ii) a parameter related to a broadcast configuration, and / or iii) a parameter related to a presentation delay.

[0500] In one embodiment, an audio signal for the speaker may be received based on an LE ISO (Low Energy Isochronous) channel. For example, if the source described above is a TV operating as an SSAP assistant, the speaker may receive an audio signal for the speaker from the source based on an LE ISO channel. For example, if the source described above is a smart phone operating as an SSAP assistant, the speaker may receive an audio signal for the speaker from a broadcast audio source (e.g., a TV, a sound bar) based on an LE ISO channel.

[0501] For example, the audio signal may be based on a Broadcast Isochronous Stream (BIS).

[0502] For example, the BIS for the speaker may be received within an ISO sub interval.

[0503] In one embodiment, the channels associated with the speaker may include i) a Front Left (FL) channel, ii) a Front Right (FR) channel, iii) a Rear Left (RL) channel, or iv) a Rear Right (RR) channel.

[0504] According to various embodiments of the present disclosure, a speaker is provided. The speaker includes a third processor corresponding to a host stack; a fourth processor corresponding to a third controller stack; a memory; a transceiver; and a speaker device. The host stack and the controller stack are connected via a Host Controller Interface (HCI). The memory may be configured to store instructions for performing a method of operating a speaker according to FIG. 31 based on instructions executed by the third processor and the fourth processor.

[0505] According to various embodiments of the present disclosure, a control device for controlling a speaker is provided. The control device includes at least one processor and at least one memory operably connected to the at least one processor. The at least one memory may be configured to store instructions for performing a method for operating a speaker according to FIG. 31 based on instructions executed by the at least one processor.

[0506] According to various embodiments of the present disclosure, one or more non-transitory computer-readable media (CRM) storing one or more instructions are provided. The one or more instructions, when executed by one or more processors, perform operations, and the operations may include a method of operating a speaker according to FIG. 31.

[0507] The claims described in the various embodiments of this specification may be combined in various ways. For example, the technical features of the method claims of the various embodiments of this specification may be combined and implemented as a device, and the technical features of the device claims of the various embodiments of this specification may be combined and implemented as a method. Furthermore, the technical features of the method claims of the various embodiments of this specification may be combined with the technical features of the device claims of the various embodiments of this specification may be combined and implemented as a device, and the technical features of the method claims of the various embodiments of this specification may be combined with the technical features of the device claims of the various embodiments of this specification may be combined and implemented as a method.

Claims

1. In a method performed by a source, A step of scanning advertisements of speakers related to a surround sound system, each advertisement including information indicating whether a Surround Sound Audio Profile (SSAP) is supported by each speaker; Step of connecting to the above speakers; and A step of transmitting information including at least one parameter to each of the above speakers; A method characterized in that at least one of the above parameters comprises a volume control parameter.

2. In paragraph 1, A method characterized in that the source comprises a TV, a sound bar or a smart phone defined to act as a SSAP assistant that manages discovery and grouping of nearby speakers.

3. In paragraph 1, A method characterized in that the speakers connected to the source belong to a group associated with the surround sound system.

4. In paragraph 3, A method characterized by comprising the step of resetting the group by excluding a specific speaker from among the above speakers.

5. In paragraph 4, Further comprising a step of receiving status information from the specific speaker; A method characterized in that the group is reset based on the state information.

6. In paragraph 5, A method characterized in that the above status information includes at least one of i) volume delta, ii) presentation delay, iii) sync offset, iv) location and / or v) battery.

7. In paragraph 4, further comprising the step of receiving periodic advertisements from said speakers; A method characterized in that the group is reset based on the periodic advertisements.

8. In paragraph 7, Each of the above periodic advertisements contains status information for each speaker, A method characterized in that the above status information includes at least one of i) volume delta, ii) presentation delay, iii) sync offset, iv) location and / or v) battery.

9. In paragraph 1, A method characterized in that the above information is transmitted based on an LE ACL (Low Energy Asynchronous Connection-Less) link.

10. In paragraph 1, A method characterized in that the above volume control parameters include i) parameters related to a common global gain for the speakers and / or ii) parameters related to an individual gain for each of the speakers.

11. In paragraph 1, A method characterized in that the at least one parameter comprises i) a parameter related to a broadcast code, ii) a parameter related to a broadcast configuration, and / or iii) a parameter related to a presentation delay.

12. In paragraph 1, A method characterized in that an audio signal for each of the above speakers is transmitted based on an LE ISO (Low Energy Isochronous) channel.

13. In paragraph 12, A method characterized in that the above audio signal is based on a BIS (Broadcast Isochronous Stream).

14. In paragraph 13, A method characterized in that the BIS for each of the above speakers is transmitted within an ISO sub interval.

15. In paragraph 1, A method characterized in that the channels associated with the above speakers include at least one of i) a Front Left (FL) channel, ii) a Front Right (FR) channel, iii) a Rear Left (RL) channel, and / or iv) a Rear Right (RR) channel.

16. In terms of source, A first processor corresponding to a host stack; a second processor corresponding to a first controller stack; a memory; and a transceiver, The above host stack and the above controller stack are connected through HCI (Host Controller Interface), A source characterized in that the memory stores instructions that cause the source to perform all steps according to the method of any one of claims 1 to 15, based on being executed by the first processor and the second processor.

17. A method performed by a speaker, A step of transmitting an advertisement to a source, the advertisement including information indicating whether a surround sound audio profile (SSAP) is supported by the speaker; a step of connecting to the above source; and comprising the step of receiving information including at least one parameter from the source; A method characterized in that at least one of the above parameters comprises a volume control parameter.

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