A communication method between the master and slave devices of a TWS Bluetooth system

Abstract

The present invention discloses a communication method between the master and slave devices of a TWS Bluetooth system. In the existing communication of the TWS Bluetooth system, the master device and the slave device perform periodic communication at the same time point according to a certain bandwidth and interval, which reduces the communication quality or causes a large number of retransmissions due to insufficient bandwidth. In the present invention, the master device of the TWS Bluetooth system establishes a classic Bluetooth link with the sound source device and the slave device, and the slave device establishes a virtual monitoring link with the sound source device. For the data interaction communication between the master device and the slave device, the master device determines the required communication bandwidth according to the communication data volume, the Bluetooth data packet type, and the allowed number of retransmissions and notifies the slave device. The master device and the slave device communicate within the communication bandwidth, and immediately release the remaining bandwidth and switch to the communication with the sound source device after the communication ends. The method of the present invention saves the overhead of the communication bandwidth between the master and slave devices and improves the communication quality of the TWS Bluetooth system by dynamically adjusting the communication bandwidth between the master and slave devices.

Description

Technical Field

[0001] The present invention belongs to the technical field of Bluetooth wireless transmission, and relates to a master-slave device communication method for a TWS Bluetooth system, which is applied to the master-slave device communication of a TWS (True Wireless Stereo) Bluetooth system, and can effectively reduce the communication bandwidth overhead between the master and slave devices of the TWS Bluetooth system and increase the reliability of the TWS Bluetooth system communication. Background Art

[0002] The current TWS Bluetooth systems on the market generally consist of a master device (such as a headset), a slave device (such as a headset), and a sound source device (such as a mobile phone), as Figure 1 shown. The usual implementation method is that the master device and the sound source device establish a first link through the classic Bluetooth BR / EDR protocol, the master device and the slave device establish a second link through the classic Bluetooth BR / EDR protocol, and the master device sends the link information of the first link to the slave device through the second link. The slave device establishes a virtual listening link relative to the sound source device to monitor the communication data between the sound source device and the master device, so as to realize the synchronous reception of the data of the sound source device by the master and slave devices.

[0003] In a TWS Bluetooth system, the master device and the slave device usually perform periodic communication at the same time point at a certain bandwidth and interval, as Figure 2 shown. However, this master-slave device communication method has deficiencies. If the master-slave communication bandwidth of the second link is set too large, the communication bandwidth of the first link and the virtual listening link to the sound source device will be reduced, and the communication quality of the first link and the virtual listening link will be lowered; if the master-slave communication bandwidth of the second link is set too small, when data needs to be exchanged between the master device and the slave device, a large number of retransmissions will occur due to insufficient bandwidth, and even the link will time out and disconnect. Summary of the Invention

[0004] The purpose of the present invention is to provide a master-slave device communication method for a TWS Bluetooth system in view of the deficiencies of the existing master-slave device communication in the TWS Bluetooth system, which can effectively reduce the communication bandwidth overhead between the master and slave devices, and at the same time better ensure the communication quality of the links between the master device and the slave device and the sound source device.

[0005] The specific technical solution of the present invention is as follows:

[0006] Step (1): The master device and the sound source device establish a classic Bluetooth connection to form a first link L1; the master device and the slave device establish a classic Bluetooth connection to form a second link L2; the slave device and the sound source device establish a virtual listening link Ln;

[0007] Step (2): Set the communication interval time t of the second link L2 to be T, where T is the communication period;

[0008] Step (3) sets the minimum time period BW-ab for the second link to maintain the connection for synchronous communication. The minimum time period BW-ab starts from the start point a of the communication cycle T.

[0009] Step (4) When L2 is only maintaining the connection without communication data interaction, it is default that the master and slave devices perform a synchronous communication starting from the start point a of the minimum time period BW-ab. The master device sends a pull packet to the slave device, and the slave device sends a null packet back to the master device after receiving it. After the minimum time period BW-ab ends, the master device switches to L1 communication, and the slave device switches to Ln communication.

[0010] Step (5) When there is communication data Dn to be interactively communicated on L2, the master device determines the required communication time B according to the communication data volume P, the Bluetooth data packet type Q, and the allowed retransmission times N. B = f(P, Q, N), where f(·) is a set fitting equation, and the Bluetooth data packet type Q and the allowed retransmission times N are preset values.

[0011] Step (6) The master device sends the control data packet D0 containing the communication time B to the slave device through L2. After the master device confirms the completion of the D0 transmission, it adjusts the communication time period BW-ac of its own L2. BW-ac = B. After the slave device confirms the receipt of D0, it adjusts the communication time period BW-ac of its own L2. In the time period BW-bc other than the minimum time period BW-ab in the communication time period BW-ac, the L2 of the master device is allowed to be multiplexed with L1, and the L2 of the slave device is allowed to be multiplexed with Ln.

[0012] Step (7) The master and slave devices interactively communicate the communication data Dn through L2 using the Bluetooth data packet type Q.

[0013] Step (8) When the communication data Dn of L2 fails to complete all interactive communications within one communication cycle, the remaining data of Dn continues to be interactively communicated within the communication time period BW-ac of the next communication cycle.

[0014] Step (9) After the interactive communication of the communication data Dn of L2 ends, the master device switches to L1 communication, and the slave device switches to Ln communication, and resumes the default communication mode of Step (4) in the next communication cycle.

[0015] Advantages of the present invention: When the master device and the slave device perform data interactive communication, they determine the required communication bandwidth according to the communication data volume, the Bluetooth data packet type, and the allowed retransmission times. The master device and the slave device communicate within the communication bandwidth, and immediately release the remaining bandwidth and switch to the communication with the sound source device after the communication ends. The method of the present invention can save the communication bandwidth overhead of the master and slave devices and improve the communication quality of the TWS Bluetooth system by dynamically adjusting the communication bandwidth of the master and slave devices. Description of the Drawings

[0016] Figure 1 It is a topology diagram of the TWS Bluetooth system;

[0017] Figure 2 It is a schematic diagram of the communication bandwidth allocation of the existing TWS Bluetooth system;

[0018] Figure 3 It is a schematic diagram of steps (3)-(4) of the method of the present invention;

[0019] Figure 4 It is a schematic diagram of steps (5)-(7) of the method of the present invention;

[0020] Figure 5 It is a schematic diagram of step (8) of the method of the present invention. Detailed implementation manners

[0021] A method for the master-slave device communication of a TWS Bluetooth system, specifically:

[0022] Step (1) The master device establishes a classic Bluetooth connection with the sound source device to form a first link L1; the master device establishes a classic Bluetooth connection with the slave device to form a second link L2; the slave device establishes a virtual listening link Ln with the sound source device;

[0023] Step (2) Set the communication interval time t = T of the second link L2, where T is the communication period;

[0024] Step (3) As Figure 3 , set the minimum time period BW-ab for the second link to maintain the connection for synchronous communication, and the minimum time period BW-ab starts from the starting point a of the communication period T;

[0025] Step (4) When L2 is only maintaining the connection without communication data interaction, it is default that the master and slave devices perform a synchronous communication starting from the starting point a of the minimum time period BW-ab. The master device sends a pull packet to the slave device, and after receiving it, the slave device sends a null packet back to the master device. After the minimum time period BW-ab ends, the master device switches to L1 communication, and the slave device switches to Ln communication;

[0026] Step (5) When there is communication data Dn to be interacted and communicated on L2, the master device determines the required communication time B according to the communication data volume P, the Bluetooth data packet type Q, and the allowed retransmission times N, B = f(P, Q, N), where f(·) is a set fitting equation, and the Bluetooth data packet type Q and the allowed retransmission times N are preset values; the Bluetooth data packet type Q is the ACL data packet type defined in the classic Bluetooth BR / EDR protocol;

[0027] Step (6) As Figure 4, the master device sends the control data packet D0 containing the communication time B to the slave device through L2. After the master device confirms the completion of the D0 transmission, it adjusts its own communication time period BW-ac of L2, where BW-ac = B. After the slave device confirms the receipt of D0, it adjusts its own communication time period BW-ac of L2; in the time period BW-bc of the communication time period BW-ac except for the minimum time period BW-ab, the L2 of the master device is allowed to be multiplexed with L1, and the L2 of the slave device is allowed to be multiplexed with Ln;

[0028] Step (7) The master and slave devices interact and communicate the communication data Dn through L2 using the Bluetooth packet type Q;

[0029] Step (8) As Figure 5 , when the communication data Dn of L2 fails to complete all the interactive communications within one communication cycle, the remaining data of Dn continues the interactive communication within the communication time period BW-ac of the next communication cycle;

[0030] Step (9) After the interactive communication of the communication data Dn of L2 ends, the master device switches to L1 communication, and the slave device switches to Ln communication, and resumes the default communication mode of step (4) in the next communication cycle.

Claims

1. A communication method between the master and slave devices of a TWS Bluetooth system, characterized in that: Step (1): The master device establishes a classic Bluetooth connection with the sound source device to form a first link L1; The master device establishes a classic Bluetooth connection with the slave device to form a second link L2; The slave device establishes a virtual listening link Ln with the sound source device; Step (2): Set the communication interval time t = T of the second link L2, where T is the communication cycle; Step (3): Set the minimum time period BW-ab for the second link to maintain the connection for synchronous communication, and the minimum time period BW-ab starts from the starting point a of the communication cycle T; Step (4): When L2 is only maintaining the connection without communication data interaction, it is default that the master and slave devices start a synchronous communication at the starting point a of the minimum time period BW-ab. The master device sends a pull packet to the slave device, and the slave device sends a null packet back to the master device after receiving it. After the minimum time period BW-ab ends, the master device switches to L1 communication, and the slave device switches to Ln communication; Step (5): When there is communication data Dn to be interactively communicated on L2, the master device determines the required communication time B according to the communication data volume P, the Bluetooth data packet type Q, and the allowed retransmission times N, B = f(P, Q, N), where f(·) is a set fitting equation, and the Bluetooth data packet type Q and the allowed retransmission times N are preset values; Step (6): The master device sends a control data packet D0 containing the communication time B to the slave device through L2. After the master device confirms that D0 is sent successfully, it adjusts its own communication time period BW-ac of L2, BW-ac = B. After the slave device confirms receiving D0, it adjusts its own communication time period BW-ac of L2; In the time period BW-bc other than the minimum time period BW-ab in the communication time period BW-ac, the master device's L2 is allowed to be multiplexed with L1, and the slave device's L2 is allowed to be multiplexed with Ln; Step (7): The master and slave devices interactively communicate the communication data Dn through L2 using the Bluetooth data packet type Q; Step (8): When the communication data Dn of L2 fails to complete all interactive communications within one communication cycle, the remaining data of Dn continues to be interactively communicated within the communication time period BW-ac of the next communication cycle; Step (9): When the interactive communication of the communication data Dn of L2 ends, the master device switches to L1 communication, and the slave device switches to Ln communication, and resumes the default communication mode of step (4) in the next communication cycle.

2. The master-slave device communication method of a TWS Bluetooth system according to claim 1, characterized in that: The Bluetooth data packet type Q is the ACL data packet type defined in the classic Bluetooth BR / EDR protocol.

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