Apparatus and method for reducing consumed current of bluetooth hid in short-range wireless communication system

Abstract

According to various embodiments of the present disclosure, provided is a method for operation of a first device in a short-range wireless communication system, the first device comprising: a first processor corresponding to a host stack; a second processor corresponding to a controller stack; a memory; an input device corresponding to a user interface (UI); an output device corresponding to the Ui; and a transceiver, the host stack and the controller stack being connected to each other through a host controller interface (HCI), and the method comprising the steps of: establishing a connection to a second device on the basis of a first time interval; determining a second time interval corresponding to N times the first time interval within the range smaller than a supervision timeout at which link loss with the second device occurs, said N being an integer greater than 0; and after transmitting a first signal to the second device, transmitting a second signal to the second device every second time interval.

Description

Device and method for reducing current consumption of a Bluetooth HID device in a short-range wireless communication system

[0001] The present disclosure relates to a device and method for reducing the power consumption of a Bluetooth HID device in a short-range wireless communication system. Specifically, the present disclosure relates to a device and method for reducing the power consumption by setting the signal transmission interval of a Bluetooth HID device within a range smaller than a supervision timeout at which a link loss occurs.

[0002]

[0003] In the existing Bluetooth standard, when using ISO channels (Isochronous Channels) or ACL (Asynchronous Connection Logical), the Central device and Peripheral device must be able to exchange Polls and Responses at the minimum cycle (Sub_Interval or Connection Interval).

[0004] In Bluetooth technology for Ultra Low Latency, the minimum cycle for transmitting and receiving signals can be reduced to less than 1ms, and since the peripheral device must receive a poll and respond every cycle, there is a disadvantage of high battery consumption.

[0005] However, since the peripheral device does not have HID (Human Interface Device) data to be transmitted by the user every cycle, most of the Poll receptions other than the HID Response that transmits HID data and the Empty Response (Response with only Ack / Nack) are empty responses.

[0006] This Empty Response has the problem of being an unnecessary operation from a battery consumption perspective.

[0007]

[0008] To solve the above-described problems, the present disclosure provides a device and method for reducing power consumption of a Bluetooth HID device in a short-range wireless communication system.

[0009] The present disclosure provides a device and method for reducing current consumption by setting a signal transmission interval of a Bluetooth HID device within a range smaller than a supervision timeout at which link loss occurs.

[0010] The technical problems to be achieved in the present disclosure 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 the present disclosure belongs from the description below.

[0011]

[0012] According to various embodiments of the present disclosure, a method of operating a first device in a short-range wireless communication system is provided, wherein the first device includes a first processor corresponding to a host stack; a second processor corresponding to a controller stack; a memory; an input device corresponding to a user interface (UI); an output device corresponding to the UI; and a transceiver, wherein the host stack and the controller stack are connected by a Host Controller Interface (HCI), and the method comprises: establishing a connection with a second device based on a first time interval; determining a second time interval corresponding to N times the first time interval within a range smaller than a Supervision Timeout at which a link loss occurs with the second device, wherein N is an integer greater than 0; and transmitting a second signal to the second device at every second time interval after transmitting a first signal to the second device.

[0013] According to various embodiments of the present disclosure, in a short-range wireless communication system, a first device includes a first processor corresponding to a host stack; a second processor corresponding to a controller stack; a memory; an input device corresponding to a user interface (UI); an output device corresponding to the UI; and a transceiver, wherein the host stack and the controller stack are connected by a Host Controller Interface (HCI), and the memory stores instructions for performing operations based on what is executed by the first processor and the second processor, wherein the operations are performed in a method for operating the first device in a short-range wireless communication system, wherein the first device includes a first processor corresponding to a host stack; a second processor corresponding to a controller stack; a memory; an input device corresponding to a user interface (UI); an output device corresponding to the UI; And a transceiver, wherein the host stack and the controller stack are connected by a Host Controller Interface (HCI), the first device is provided, comprising: a step of establishing a connection with a second device based on a first time interval; a step of determining a second time interval corresponding to N times the first time interval within a range smaller than a Supervision Timeout in which a link loss occurs with the second device, wherein N is an integer greater than 0; and a step of transmitting a second signal to the second device at every second time interval after transmitting a first signal to the second device.

[0014]

[0015] To solve the above-described problems, the present disclosure can provide a device and method for reducing power consumption of a Bluetooth HID device in a short-range wireless communication system.

[0016] The present disclosure can provide a device and method for reducing current consumption by setting a signal transmission interval of a Bluetooth HID device within a range smaller than a supervision timeout at which link loss occurs.

[0017]

[0018] The accompanying drawings are intended to aid in understanding the present disclosure and, together with detailed descriptions, may provide embodiments of the present disclosure. However, the technical features of the present disclosure 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.

[0019] FIG. 1 is a schematic diagram showing an example of a wireless communication system using the Bluetooth low energy technology proposed in the present disclosure.

[0020] FIG. 2 shows an example of an internal block diagram of a device capable of implementing the methods proposed in the present disclosure.

[0021] FIG. 3 illustrates an example of a Bluetooth communication architecture to which the methods proposed in the present disclosure can be applied.

[0022] Figure 4 shows an example of the structure of the GATT (Generic Attribute Profile) of Bluetooth low energy.

[0023] 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 disclosure can be applied.

[0024] Figure 6 shows an example of a process for transmitting and receiving signals between a conventional host device (central device) and an HID device (peripheral device).

[0025] FIG. 7 illustrates an example of a process for transmitting and receiving signals between a host device (central device) and an HID device (peripheral device) according to various embodiments of the present disclosure.

[0026] FIG. 8 illustrates an example of an operation process of a host device (central device) in a system according to various embodiments of the present disclosure.

[0027] FIG. 9 illustrates an example of an operation process of a wireless device in a short-range wireless communication system according to various embodiments of the present disclosure.

[0028]

[0029] In various embodiments of the present disclosure, “A or B” may mean “only A,” “only B,” or “both A and B.” In other words, in various embodiments of the present disclosure, “A or B” may be interpreted as “A and / or B.” For example, in various embodiments of the present disclosure, “A, B or C” may mean “only A,” “only B,” “only C,” or “any combination of A, B and C.”

[0030] In various embodiments of the present disclosure, 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."

[0031] In various embodiments of the present disclosure, “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 disclosure, 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.”

[0032] Additionally, in various embodiments of the present disclosure, “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.”

[0033]

[0034] Figure 1 is a schematic diagram showing an example of a wireless communication system using the Bluetooth low energy technology proposed in this specification.

[0035] A wireless communication system (100) includes at least one server device (Server device, 120) and at least one client device (Client device, 110).

[0036] The server device and client device perform Bluetooth communication using Bluetooth Low Energy (BLE, hereinafter referred to as 'BLE' for convenience) technology.

[0037] 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.

[0038] Additionally, BLE technology simplifies the connection process between devices and is designed to have a smaller packet size compared to Bluetooth BR / EDR technology.

[0039] 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.

[0040] 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.

[0041] The above server device (120) may be expressed as a data service device, a slave device, a slave, a server, a conductor, a host device, a gateway, a sensing device, a monitoring device, a first device, a second device, etc.

[0042] The above client device (110) may be expressed as a master device, a master, a client, a member, a sensor device, a sink device, a collector, a third device, a fourth device, etc.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] The above client device (120) refers to a device that requests data information and data transmission from a server device.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] FIG. 2 shows an example of an internal block diagram of a device capable of implementing the methods proposed in this specification.

[0056] As illustrated in FIG. 2, the master 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).

[0057] 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.

[0058] In addition, as illustrated in FIG. 2, the slave 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).

[0059] The above 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.

[0060] The above network interface (116, 126) refers to a unit (or module) that can transmit data, such as request / response, command, notification, instruction / confirmation messages, etc., between devices using Bluetooth technology.

[0061] 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.

[0062] The above control unit (114, 124) refers to a module that controls the overall operation of the master device (110) or slave device (120), and requests transmission of a message to the network interface or controls processing of a received message.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] As discussed above, BLE technology has a small duty cycle and can significantly reduce power consumption through low data rates.

[0069] Figure 3 shows an example of a Bluetooth communication architecture to which the methods proposed in this specification can be applied.

[0070] Specifically, FIG. 3 shows an example of the architecture of Bluetooth LE (Low Energy).

[0071] 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.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] In some cases, the controller stack and the host stack may operate or execute on the same processing device within a processor module.

[0076] 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.

[0077] The host stack multiplexes various protocols, profiles, etc. provided above Bluetooth using L2CAP.

[0078] First, L2CAP (Logical Link Control and Adaptation Protocol,360) provides a single bidirectional channel for transmitting data to a specific protocol or profile.

[0079] L2CAP may be capable of multiplexing data between upper layer protocols, segmenting and reassembling packages, and managing multicast data transmission.

[0080] BLE uses three fixed channels (one for signaling CH, one for Security Manager, and one for Attribute protocol).

[0081] On the other hand, BR / EDR (Basic Rate / Enhanced Data Rate) uses dynamic channels and supports protocol service multiplexer, retransmission, streaming mode, etc.

[0082] SM (Security Manager, 350) is a protocol for authenticating devices and providing key distribution.

[0083] 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.

[0084] 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.

[0085] 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.

[0086] 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.

[0087] 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.

[0088] 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.

[0089] 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:

[0090] ① Service: Defines the basic operation of the device through a combination of data-related behaviors.

[0091] ② Include: Defines the relationship between services

[0092] ③ Characteristics: Data values ​​used in the service

[0093] ④ Behavior: Computer-readable format defined as UUID (Universal Unique Identifier, value type)

[0094] 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.

[0095] Battery: How to exchange battery information

[0096] Time: A method for exchanging time information

[0097] FindMe: Distance-based alarm service

[0098] Proximity: How to Exchange Battery Information

[0099] Time: A method for exchanging time information

[0100] 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.

[0101] 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.

[0102] The controller stack includes a physical layer (390), a link layer (380), and a host controller interface (370).

[0103] 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.

[0104] The link layer (380) transmits or receives Bluetooth packets.

[0105] 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.

[0106] 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.

[0107] Below, we will briefly look at the procedures of Bluetooth Low Energy (BLE) technology.

[0108] BLE procedures can be divided into device filtering procedures, advertising procedures, scanning procedures, discovering procedures, and connecting procedures.

[0109] Device Filtering Procedure

[0110] Device filtering procedures are a way to reduce the number of devices that respond to requests, instructions, notifications, etc. in the controller stack.

[0111] 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.

[0112] 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.

[0113] 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.

[0114] A scanning device is a device that performs scanning and transmits scan requests.

[0115] 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.

[0116] However, if a device filtering procedure is used to make sending scan requests unnecessary, the scanning device may ignore advertising packets transmitted from the advertising device.

[0117] 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.

[0118] Advertising Procedure

[0119] An advertising device performs an advertising procedure to perform a non-directional broadcast to devices within the area.

[0120] Here, non-directional broadcast refers to broadcast in all directions rather than broadcasting in a specific direction.

[0121] 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).

[0122] The advertising process is used to establish a Bluetooth connection with a nearby initiating device.

[0123] Alternatively, the advertising procedure may be used to provide periodic broadcasts of user data to scanning devices listening on the advertising channel.

[0124] In the advertising process, all advertisements (or advertising events) are broadcast through the advertising physical channel.

[0125] 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.

[0126] Broadcast user data sent as part of advertising packets is dynamic data, whereas scan response data is typically static data.

[0127] 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.

[0128] Scanning Procedure

[0129] 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.

[0130] 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.

[0131] The above scanning procedure can be used while connecting with other BLE devices in a BLE piconet.

[0132] If the scanning device receives a broadcasted advertising event and is in initiator mode, which allows it to initiate a connection request, the scanning device can initiate a Bluetooth connection with the advertising device by transmitting a connection request to the advertising device over the advertising physical channel.

[0133] 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.

[0134] Discovery Procedure

[0135] 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.

[0136] The discovery process is performed asymmetrically. A Bluetooth device attempting to locate other devices in its vicinity is called a discovering device, and it listens for devices advertising scannable advertising events. A Bluetooth device that has been discovered and is available to other devices is called a discoverable device, and it actively broadcasts advertising events over the advertising (broadcast) physical channel to make it scannable.

[0137] Both the discovering device and the discoverable device may already be connected to other Bluetooth devices in the piconet.

[0138] Connecting Procedure

[0139] The connection procedure is asymmetric, requiring one Bluetooth device to perform an advertising procedure while another Bluetooth device performs a scanning procedure.

[0140] 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.

[0141] Next, we will briefly look at the operating states in BLE technology, namely Advertising State, Scanning State, Initiating State, and Connection State.

[0142] Advertising State

[0143] 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.

[0144] 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.

[0145] Scanning State

[0146] 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.

[0147] There are two types of scanning states: passive scanning and active scanning, and each scanning type is determined by the host.

[0148] No separate time or advertising channel index is defined for performing scanning.

[0149] 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.

[0150] 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.

[0151] In passive scanning, the link layer only receives packets and does not transmit any packets.

[0152] 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.

[0153] Initiating State

[0154] The link layer enters the initiated state at the direction of the host (stack).

[0155] When the link layer is in the initiating state, the link layer listens for advertising channel indices.

[0156] During the initiation state, the link layer listens for advertising channel indices during the scan window period.

[0157] connection state

[0158] 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.

[0159] 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.

[0160] When two devices are connected, they act in different roles.

[0161] 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.

[0162] Below, we will briefly examine the packets defined in the Bluetooth interface. BLE devices use the packets defined below.

[0163] Packet Format

[0164] The Link Layer has only one packet format, which is used for both advertising channel packets and data channel packets.

[0165] Each packet consists of four fields: Preamble, Access Address, PDU, and CRC.

[0166] 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.

[0167] Advertising Channel PDU

[0168] Advertising channel PDUs (Packet Data Units) have a 16-bit header and payloads of various sizes.

[0169] The PDU type field of the advertising channel PDU included in the header indicates the PDU type as defined in Table 1 below.

[0170] PDU TypePDU NameChannelPermitted PHYsLE 1MLE 2MLE Coded0000bADV_INDPrimary AdvertisingO0001bADV_DIRECT_INDPrimary AdvertisingO0010bADV_NONCONN_INDPrimary AdvertisingO0011bSCAN_REQPrimary AdvertisingOAUX_SCAN_REQSecondary AdvertisingOOO0100bSCAN_RSPPrimary AdvertisingO0101bCONNECT_INDPrimary AdvertisingOAUX_CONNECT_REQSecondary AdvertisingOOO0110bADV_SCAN_INDPrimary AdvertisingO

[0171] Advertising PDU

[0172] The advertising channel PDU types below are called advertising PDUs and are used in specific events.

[0173] ADV_IND: Connectable non-directional advertising event

[0174] ADV_DIRECT_IND: Connectable directional advertising event

[0175] ADV_NONCONN_IND: Non-directional ad event that is not reachable

[0176] ADV_SCAN_IND: Scannable non-directional ad event

[0177] 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.

[0178] Scanning PDU

[0179] The advertising channel PDU type below is called a scanning PDU and is used in the conditions described below.

[0180] SCAN_REQ: Sent by the link layer in scanning state and received by the link layer in advertising state.

[0181] SCAN_RSP: Sent by the link layer in advertising state and received by the link layer in scanning state.

[0182] Initiating PDU

[0183] The advertising channel PDU type below is called an initiation PDU.

[0184] CONNECT_REQ: Sent by the link layer in the initiating state and received by the link layer in the advertising state.

[0185] Data Channel PDU

[0186] A data channel PDU has a 16-bit header, a payload of variable size, and may include a Message Integrity Check (MIC) field.

[0187] The procedures, states, packet formats, etc. in BLE technology discussed above can be applied to perform the methods proposed in this specification.

[0188]

[0189] Figure 4 shows an example of the structure of the GATT (Generic Attribute Profile) of Bluetooth low energy.

[0190] Referring to Figure 4, a structure for exchanging profile data of Bluetooth low energy can be examined.

[0191] Specifically, GATT (Generic Attribute Profile) defines how to exchange data using services and characteristics between Bluetooth LE devices.

[0192] Typically, a peripheral device (e.g., a sensor device) acts as a GATT server and has definitions for services and characteristics.

[0193] 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.

[0194] 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.

[0195] The above profile consists of one or more services, and the services may consist of one or more characteristics or other services.

[0196] 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).

[0197] 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.

[0198] 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.

[0199] The above attribute consists of four components and has the following meanings:

[0200] - handle: address of the property

[0201] - Type: Type of property

[0202] - Value: The value of the property

[0203] - Permission: Access rights to properties

[0204]

[0205] FIG. 5 is a flowchart showing an example of a connection procedure method in Bluetooth low energy technology to which the present invention can be applied.

[0206] The server transmits advertising messages to the client through three advertising channels (S5010).

[0207] 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).

[0208] 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.

[0209] 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.

[0210] The remaining 37 channels are used for data exchange after connection as data channels.

[0211] 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.

[0212] In this case, the server transmits a Scan Response message containing additional data in response to a Scan Request message to the client.

[0213] 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.

[0214] 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.

[0215] Next, the client sends a connection request message to the server to establish a Bluetooth connection with the server (S5020).

[0216] Through this, a Link Layer (LL) connection is established between the server and the client.

[0217] Afterwards, the server and client perform security establishment procedures.

[0218] The secure establishment procedure may be interpreted as or performed incorporating Secure Simple Pairing.

[0219] That is, the security establishment procedure can be carried out through Phase 1 to Phase 3.

[0220] Specifically, a pairing procedure (phase 1) is performed between the server and the client (S5030).

[0221] 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.

[0222] 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.

[0223] Next, as phase 2, legacy pairing or secure connections are performed between the server and the client (S5040).

[0224] In Phase 2, a 128-bit temporary key and a short term key (STK) are generated to perform legacy pairing.

[0225] - Temporary Key: Key created to generate STK

[0226] - Short Term Key (STK): Key value used to create an encrypted connection between devices.

[0227] If a secure connection is performed in Phase 2, a 128-bit Long Term Key (LTK) is generated.

[0228] - Long Term Key (LTK): A key value used not only for encrypted connections between devices but also for future connections.

[0229] Next, as phase 3, a key distribution procedure is performed between the server and the client (S5050).

[0230] This establishes a secure connection between the server and client, forming an encrypted link to enable data transmission and reception.

[0231] Isochronous Channel General

[0232] For audio signals, you can see that audio streaming data or audio data occurs periodically at Idle Event Interval intervals.

[0233] 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.

[0234] 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.

[0235] 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.

[0236] 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.

[0237] Definition of Isochronous Channels and Related Mechanisms

[0238] A new channel, the Isochronous Channel, is defined to transmit periodically occurring data using BLE technology.

[0239] An isochronous channel is a channel used to transmit isochronous data between devices that use isochronous streams (e.g., Conductor-Member).

[0240] Isochronous data refers to data that is transmitted periodically or regularly at specific time intervals.

[0241] 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.

[0242]

[0243] Composition of various embodiments of the present disclosure

[0244] The background for the various embodiments of the present disclosure is as follows.

[0245] (1) In the existing Bluetooth standard, when using ISO channels (Isochronous Channels) or ACL (Asynchronous Connection Logical), the Central device and Peripheral device must be able to exchange Poll and Response at the minimum cycle (Sub_Interval or Connection Interval).

[0246] (2) In Bluetooth technology for Ultra Low Latency, the minimum cycle for transmitting and receiving signals can be reduced to less than 1ms, and since the peripheral device must receive a poll and respond every cycle, there is a disadvantage of high battery consumption.

[0247] (3) However, since the peripheral device does not have HID (Human Interface Device) data to be transmitted by the user every cycle, most of the Poll receptions other than the HID Response that transmits HID data and the Empty Response (Response with only Ack / Nack) are received.

[0248] (4) This Empty Response has the problem of being an unnecessary operation from the perspective of battery consumption.

[0249]

[0250] Proposals according to various embodiments of the present disclosure are as follows.

[0251] (1) The present invention relates to a method and device for receiving a poll and sending a response only when an integer multiple of the first cycle between a central device and a peripheral device is used by HID (Human Interface Device) devices using Bluetooth technology using an ISO channel or ACL, or when the HID device has data to send to the central device, or before a Supervision Timeout (before a Link Lost occurs).

[0252] (2) From a battery consumption perspective, unnecessary Empty Response operations can be reduced within the range defined in the standard.

[0253]

[0254] The effects according to various embodiments of the present disclosure are as follows.

[0255] (1) Most Bluetooth HID devices are battery-operated, so power consumption is an important factor in the product.

[0256] (2) Through the present invention, the battery consumption of the HID device can be drastically reduced by reducing unnecessary Bluetooth transmission and reception.

[0257]

[0258] Figure 6 shows an example of a process for transmitting and receiving signals between a conventional host device (central device) and an HID device (peripheral device).

[0259] Referring to Figure 6, the Central device and the Peripheral device exchange Poll and Response (Ack / Nack) at every minimum cycle (Sub Interval or Connection Interval).

[0260] For HID devices, a significant portion are Poll and Empty Response (Ack / Nack), and there are not many HID Responses that transmit HID Data intended by the user.

[0261] The host device (Central device) can be a TV, smartphone, laptop, etc.

[0262] HID devices (Peripheral devices) can be keyboards, mice, gamepads, etc.

[0263] The Host device (Central device) transmits a signal to the HID device (Peripheral device), and then transmits a signal to the HID device (Peripheral device) at a Sub Interval / Connection Interval cycle. The Host device (Central device) can receive a response signal from the HID device (Peripheral device).

[0264] If there is no data to transmit, the response signal is an empty response and corresponds to an acknowledgment / negative acknowledgment (ACK / NACK) for the signal transmitted by the host device (central device).

[0265] If there is data to transmit, the response signal corresponds to a HID Response containing the HID data intended by the user.

[0266] HID devices (Peripheral devices) consume a lot of power because they transmit and receive signals at the same time interval as the Host device (Central device).

[0267]

[0268] FIG. 7 illustrates an example of a process for transmitting and receiving signals between a host device (central device) and an HID device (peripheral device) according to various embodiments of the present disclosure.

[0269] Referring to Figure 7, the Host device (Central device) receives a Poll from the HID device (Peripheral device) every integer multiple of the minimum cycle and responds.

[0270] An integer multiple of the minimum period can be randomly selected as long as Supervision Timeout (Link Lost) does not occur.

[0271] However, when there is data to be sent from a peripheral device, it always receives a Poll and transmits HID Data as a HID Response.

[0272] The host device (Central device) can be a TV, smartphone, laptop, etc.

[0273] HID devices (Peripheral devices) can be keyboards, mice, gamepads, etc.

[0274] The Host device (Central device) transmits a signal to the HID device (Peripheral device), and then transmits a signal to the HID device (Peripheral device) at a Sub Interval / Connection Interval cycle. The Host device (Central device) can receive a response signal from the HID device (Peripheral device).

[0275] If there is no data to transmit, the response signal is an empty response and corresponds to an acknowledgment / negative acknowledgment (ACK / NACK) for the signal transmitted by the host device (central device).

[0276] If there is data to transmit, the response signal corresponds to a HID Response containing the HID data intended by the user.

[0277] HID devices (Peripheral devices) transmit and receive signals at longer intervals than Host devices (Central devices), so power consumption is reduced.

[0278] For example, a HID device (Peripheral device) can transmit and receive signals at a time interval that is an integer number N times greater than that of a Host device (Central device).

[0279]

[0280] FIG. 8 illustrates an example of an operation process of a host device (central device) in a system according to various embodiments of the present disclosure.

[0281] Referring to Figure 8, the Host device (Central device) receives a Poll from the HID device (Peripheral device) every integer multiple of the minimum cycle and responds.

[0282] An integer multiple of the minimum period can be randomly selected as long as Supervision Timeout (Link Lost) does not occur.

[0283] However, when there is data to be sent from a peripheral device, it always receives a Poll and transmits HID Data as a HID Response.

[0284] In step 1, the Central device and the Peripheral device are connected at regular intervals.

[0285] In step 2, after a set period of time has elapsed since the connection was established, the Central device determines whether to apply a current consumption reduction technique according to various embodiments of the present invention. Whether to apply a current consumption reduction technique may be determined based on whether there is an abnormality in signal transmission and reception with the Peripheral device. If there is no abnormality in signal transmission and reception with the Peripheral device, the Central device may decide to apply a current consumption reduction technique according to various embodiments of the present invention. Otherwise, the Central device may remain in the initial connection cycle.

[0286] In step 3, the Central device determines an integer multiple N for the signal transmission / reception cycle with the Peripheral device. The integer multiple N can be randomly determined from among values ​​such that the minimum cycle XN is not greater than the Supervision Timeout value at which Link Loss occurs.

[0287] In Step 4, the Central and Peripheral devices are connected at a frequency N times the minimum cycle. However, the Central and Peripheral devices can receive polls at any time if there is data to be sent to them.

[0288]

[0289] [Description of Host Device Claim]

[0290] The embodiments described below are specifically described with reference to FIG. 9 in terms of terminal operation. The methods described below are distinguished for convenience of explanation, and it is understood that, unless mutually exclusive, some components of one method may be substituted for or combined with some components of another method.

[0291] FIG. 9 illustrates an example of an operation process of a wireless device in a short-range wireless communication system according to various embodiments of the present disclosure.

[0292] According to various embodiments of the present disclosure, a method is provided that is performed by a wireless device (i.e., a first device) in a short-range wireless communication system.

[0293] The first device includes a first processor corresponding to a host stack; a second processor corresponding to a controller stack; a memory; an input device corresponding to a user interface (UI); an output device corresponding to the UI; and a transceiver. The host stack and the controller stack are connected via a Host Controller Interface (HCI).

[0294] At step S901, the first device establishes a connection with the second device based on the formulation 1 time interval.

[0295] In step S902, the first device determines a second time interval equal to N times the first time interval within a range less than a supervision timeout during which a link loss occurs with the second device, where N is an integer greater than 0.

[0296] In step S903, the first device transmits a first signal to the second device, and then transmits a second signal to the second device at second time intervals.

[0297]

[0298] According to various embodiments of the present disclosure, N may be an integer greater than 0 and less than or equal to M, which is a maximum integer multiple of the first time interval within a range less than the Supervision Timeout during which link loss with the second device occurs.

[0299] According to various embodiments of the present disclosure, the N may be randomly determined from among integers between 1 and the M.

[0300] According to various embodiments of the present disclosure, the embodiment of FIG. 9 may further include a step of transmitting a third signal after a time interval of (N+1) times the first time interval from the time of transmission of the second signal, if the second signal is transmitted to the second device without error.

[0301] According to various embodiments of the present disclosure, the embodiment of FIG. 9 may further include a step of transmitting a fourth signal after a time interval of N times the first time interval from the time of transmission of the third signal, if an error occurs in the transmission of the third signal to the second device.

[0302] According to various embodiments of the present disclosure, the embodiment of FIG. 9 may further include a step of transmitting a fifth signal after a time interval of (N-1) times the first time interval from the time of transmission of the second signal, if an error occurs in the transmission of the second signal to the second device.

[0303] According to various embodiments of the present disclosure, whether the second signal was transmitted to the second device without error can be determined based on whether a response signal to the second signal is received from the second device.

[0304]

[0305] According to various embodiments of the present disclosure, a wireless device is provided in a short-range wireless communication system. The wireless device includes a first processor corresponding to a host stack; a second processor corresponding to a controller stack; a memory; an input device corresponding to a user interface (UI); an output device corresponding to the UI; and a transceiver. 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 an operating method of a first device according to FIG. 9 based on instructions executed by the first processor and the second processor.

[0306]

[0307] According to various embodiments of the present disclosure, a control device for controlling a wireless device in a short-range wireless communication system 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 an operating method of a first device according to FIG. 9 based on instructions executed by the at least one processor.

[0308]

[0309] 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 the operating method of the first device according to FIG. 9.

[0310]

[0311] The claims described in the various embodiments of the present disclosure may be combined in various ways. For example, the technical features of the method claims of the various embodiments of the present disclosure may be combined and implemented as a device, and the technical features of the device claims of the various embodiments of the present disclosure may be combined and implemented as a method. Furthermore, the technical features of the method claims of the various embodiments of the present disclosure may be combined and implemented as a device, and the technical features of the method claims of the various embodiments of the present disclosure may be combined and implemented as a method.

Claims

1. In a method for operating a first device in a short-range wireless communication system, the first device includes a first processor corresponding to a host stack; a second processor corresponding to a controller stack; a memory; an input device corresponding to a user interface (UI); an output device corresponding to the UI; and a transceiver, wherein the host stack and the controller stack are connected by a Host Controller Interface (HCI). A step of establishing a connection with a second device based on a first time interval; A step of determining a second time interval corresponding to N times the first time interval within a range smaller than a supervision timeout at which a link loss occurs with the second device, wherein N is an integer greater than 0; A step of transmitting a first signal to the second device, and then transmitting a second signal to the second device at second time intervals, method.

2. In paragraph 1, The above N is an integer greater than or equal to 0 and less than or equal to M, which is a maximum integer multiple of the first time interval within a range less than the Supervision Timeout during which link loss with the second device occurs. method.

3. In paragraph 2, The above N is randomly determined from among integers between 1 and M. method.

4. In paragraph 1, If the second signal is transmitted to the second device without error, further comprising a step of transmitting a third signal after a time interval of (N+1) times the first time interval from the time of transmitting the second signal. method.

5. In paragraph 4, If an error occurs in the transmission of the third signal to the second device, the method further includes the step of transmitting the fourth signal after a time interval of N times the first time interval from the time of transmitting the third signal. method.

6. In paragraph 1, If an error occurs in the transmission of the second signal to the second device, further comprising the step of transmitting the fifth signal after a time interval of (N-1) times the first time interval from the time of transmission of the second signal. method.

7. In paragraph 1, Whether the second signal is transmitted to the second device without error is determined based on whether a response signal to the second signal is received from the second device. method.

8. In a short-range wireless communication system, in a first device, A first processor corresponding to a host stack; a second processor corresponding to a controller stack; a memory; an input device corresponding to a user interface (UI); an output device corresponding to the UI; and a transceiver. The above host stack and the above controller stack are connected through HCI (Host Controller Interface), The above memory stores instructions for performing operations based on what is executed by the first processor and the second processor, The above actions are, In a method of operating a first device in a short-range wireless communication system, the first device includes a first processor corresponding to a host stack; a second processor corresponding to a controller stack; a memory; an input device corresponding to a user interface (UI); an output device corresponding to the UI; and a transceiver, wherein the host stack and the controller stack are connected by a Host Controller Interface (HCI). A step of establishing a connection with a second device based on a first time interval; A step of determining a second time interval corresponding to N times the first time interval within a range smaller than a supervision timeout at which a link loss occurs with the second device, wherein N is an integer greater than 0; A step of transmitting a first signal to the second device, and then transmitting a second signal to the second device at second time intervals, Device 1.

9. In paragraph 8, The above N is an integer greater than or equal to 0 and less than or equal to M, which is a maximum integer multiple of the first time interval within a range less than the Supervision Timeout during which link loss with the second device occurs. Device 1.

10. In paragraph 9, The above N is randomly determined from among integers between 1 and M. Device 1.

11. In paragraph 8, The above actions are, If the second signal is transmitted to the second device without error, further comprising a step of transmitting a third signal after a time interval of (N+1) times the first time interval from the time of transmitting the second signal. Device 1.

12. In paragraph 11, The above actions are, If an error occurs in the transmission of the third signal to the second device, the method further includes the step of transmitting the fourth signal after a time interval of N times the first time interval from the time of transmitting the third signal. Device 1.

13. In paragraph 8, The above actions are, If an error occurs in the transmission of the second signal to the second device, further comprising the step of transmitting the fifth signal after a time interval of (N-1) times the first time interval from the time of transmission of the second signal. Device 1.

14. In paragraph 8, Whether the second signal is transmitted to the second device without error is determined based on whether a response signal to the second signal is received from the second device. Device 1.

Images