Bluetooth device, bluetooth device multi-link fast switching method and system

Abstract

The application discloses a Bluetooth device, a Bluetooth device multi-link fast switching method and system, the method comprises the following steps: calculating the syncword time difference between the time when the device acting as a slave role in each link receives the packet from the source device and the time when the device acting as a slave role in each link receives the packet from the source device; adjusting the microsecond clock in the local clock of the device acting as a slave role in each link based on the syncword time difference, keeping the microsecond clock offset of the device acting as a slave role in each link unchanged, and keeping the local clock of the device acting as a slave role in each link and the clock of the source device synchronized. In the application, the phase difference of the clock system of each link can be kept synchronized, so that the microsecond clock offset does not need to be updated when switching, part of the switching time consumption ratio can be saved, and the purpose of fast switching is achieved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of Bluetooth communication, and particularly relates to a Bluetooth device, a Bluetooth device multi-link fast switching method and a system. BACKGROUND

[0002] With the increasingly wide application of Bluetooth technology in the field of audio, Bluetooth audio devices play a very important role in people's daily life. When classic Bluetooth and BLE Bluetooth are used in more complex audio application fields, such as TWS voice, voice broadcast, voice MESH and the like, the Bluetooth device in a multi-link and multi-role needs to have the function of switching between two Bluetooth piconet networks. At present, the common method is to define the Bluetooth connection established between the Bluetooth master device and the source device as piconet1, define the Bluetooth connection established between the Bluetooth slave device and the master device as piconet2, and the Bluetooth slave device establishes a listening link with the source device on piconet1. Since there are situations of packet loss or receiving errors in the listening link, the Bluetooth master device usually needs to forward the lost or received error packets to the Bluetooth slave device to improve the communication efficiency.

[0003] In the current scheme, the master device as a relay node and the slave device as a listening node need to switch between the two links, and the time consumption of the switching process between the two links will have a significant impact on the bandwidth of the link.

[0004] The internal clock of the Bluetooth device is calculated in two parts, one part is bt_clk in units of half Bluetooth time slots, with a unit of 312.5us, and the other part is an internal microsecond timer, with a unit of us, ranging from 0 to 1249us. According to the communication protocol standard of classic Bluetooth, the clock in the Bluetooth piconet network takes the local clock of the Bluetooth device in the Master role as the standard, and the Slave role needs to constantly update the Bluetooth clock offset bt_clk_offset in units of half Bluetooth time slots 312.5us and the microsecond-level clock offset us_offset in units of us to keep synchronization with the Master device clock.

[0005] In the current scheme, when piconet1 is running, the native clock local clock of the source device is taken as the master clock of piconet1, recorded as Bluetooth clock bt_clk1 and microsecond clock us_n1. The Bluetooth master in piconet1 keeps clock synchronization with the source device according to the Bluetooth clock offset bt_clk_offset1 and microsecond clock offset us_offset1 obtained when the connection is established; since the Bluetooth clock bt_clk1 and microsecond clock us_n1 of the source device will drift over time, the Bluetooth master needs to periodically update its Bluetooth clock offset bt_clk_offset1 and microsecond clock offset us_offset1 subsequently.

[0006] When piconet1 is running, the Bluetooth slave listens to the music package of the source device as the Slave on the listening link, and the slave obtains the Bluetooth clock offset bt_clk_offset3 and microsecond clock offset us_offset3 when the listening link is established with the source device, and starts to keep synchronization with the source device; since the Bluetooth clock bt_clk1 and microsecond clock us_n1 of the source device will drift over time, the Bluetooth slave needs to periodically update its Bluetooth clock offset bt_clk_offset3 and microsecond clock offset us_offset3 subsequently.

[0007] After piconet1 is running, when switching to piconet2, the Bluetooth master simultaneously acts as the Master in piconet2 and the Slave in piconet1, and its native clock local clock is taken as the master clock of piconet2, recorded as Bluetooth clock bt_clk2 and microsecond clock us_n2. The Bluetooth slave acts as the Slave in piconet2 and starts to keep synchronization with the Bluetooth master according to the Bluetooth clock offset bt_clk_offset2 and microsecond clock offset us_offset2 obtained when the connection is established; since the Bluetooth clock bt_clk2 and microsecond clock us_n2 of the Bluetooth master drift, the slave needs to periodically update bt_clk_offset2 and us_offset2 subsequently.

[0008] When the link is switched, the Bluetooth master acting as the relay node needs to switch between (bt_clk_offset1, us_offset1) on piconet1 and (bt_clk2, us_n2) on piconet2; the Bluetooth slave acting as the listening node needs to switch between (bt_clk_offset2, us_offset2) on piconet2 and (bt_clk_offset3, us_offset3) on the listening link.

[0009] In the current solution, (bt_clk1, us_n1) and (bt_clk2, us_n2) are two different clock systems with no relation to each other. Furthermore, as the system clock drifts, the phase difference between these two clock systems changes, resulting in random values ​​for bt_clk_offset and us_offset. This necessitates updating the Bluetooth clock offset bt_clk_offset and microsecond clock offset us_offset during each link switch. Simultaneously, because the phase difference between these two clock systems is randomly changing, Bluetooth communication requires preparation for the next time slot's transmission and reception in the previous time slot. Since this is not time slot aligned, the RF and modem may lack sufficient preparation time within a time slot to complete the current Master or Slave activity. These two issues significantly increase the switching time percentage when link switches are frequent, significantly impacting bandwidth and leading to low communication efficiency. Summary of the Invention

[0010] To address the aforementioned issues, this invention proposes a Bluetooth device, a method and system for fast multi-link switching in Bluetooth devices, which can significantly reduce the time consumption during link switching and improve communication efficiency and Bluetooth communication bandwidth.

[0011] To achieve the above-mentioned technical objectives and effects, the present invention is implemented through the following technical solution:

[0012] In a first aspect, the present invention provides a method for fast multi-link switching in Bluetooth devices, comprising:

[0013] Calculate the syncword time difference between two consecutive times when the device acting as a Slave receives a packet from the source device in each link used for communication with the source device;

[0014] Based on the syncword time difference, the microsecond clock in the local clock of the device acting as a slave in each link is adjusted so that the microsecond clock offset of the device acting as a slave in each link remains unchanged, and the local clock of the device acting as a slave in each link is synchronized with the clock of the source device.

[0015] Optionally, when the Bluetooth link piconet1, which includes a source device and a Bluetooth master device connected in communication, is running, the source device acts as the Master in the Bluetooth link piconet1, and the Bluetooth master device acts as the Slave in the Bluetooth link piconet1.

[0016] In response to the Bluetooth master receiving the packet sent by the source device in the Bluetooth link piconet1, the syncword time difference between the two times when the Bluetooth master receives the packet sent by the source device is calculated, and the microsecond clock us1 in the local clock of the Bluetooth master is adjusted based on the syncword time difference, so that the local clock of the Bluetooth master is synchronized with the clock of the source device, and the microsecond clock offset us_offset1 remains unchanged.

[0017] Optionally, when the Bluetooth link piconet2 including the Bluetooth master and the Bluetooth slave connected in communication is running, the Bluetooth master acts as a Master role in the Bluetooth link piconet2, and the Bluetooth slave acts as a Slave role in the Bluetooth link piconet2.

[0018] When the Bluetooth link piconet2 is running, the microsecond clocks in the local clocks of the Bluetooth master and the Bluetooth slave are adjusted at the same time, so that the clock phase difference between the Bluetooth master and the Bluetooth slave, between the Bluetooth master and the source device, and between the Bluetooth slave and the source device is all 625us.

[0019] Optionally, when the Bluetooth link piconet1 is running, the difference clk_adj_us between the microsecond clock offset us_offset1 of the Bluetooth master and 625us is calculated by the Bluetooth master.

[0020] When the Bluetooth link piconet2 is running, the microsecond clocks in the local clocks of the Bluetooth master and the Bluetooth slave are adjusted at the same time, and the adjustment value is clk_adj_us, so that the microsecond clock offset us_offset1 remains 625us thereafter.

[0021] Optionally, when the Bluetooth link piconet1 is running, the source device sends a packet to the Bluetooth master, the Bluetooth slave establishes a listening link with the source device, and the Bluetooth slave acts as a Slave role in the listening link.

[0022] In response to the Bluetooth slave receiving the packet sent by the source device in the listening link, the syncword time difference between the two times when the Bluetooth slave receives the packet sent by the source device is calculated, and the microsecond clock us3 in the local clock of the Bluetooth slave is adjusted based on the syncword time difference, so that the local clock of the Bluetooth slave is synchronized with the clock of the source device, and the microsecond clock offset us_offset3 remains unchanged.

[0023] Optionally, when the Bluetooth link piconet2 including the Bluetooth master and the Bluetooth slave connected in communication is running, the Bluetooth master acts as a Master role in the Bluetooth link piconet2, and the Bluetooth slave acts as a Slave role in the Bluetooth link piconet2.

[0024] At the end of the operation of the Bluetooth link piconet1, in response to the Bluetooth slave device switching from the listening link to the Bluetooth link piconet2, using the local clock adjusted by the microsecond clock adjustment in the local clock on the Bluetooth link piconet1 with the syncword time difference, as the system clock of the Bluetooth link piconet2, the local clocks of the Bluetooth slave device and the Bluetooth master device remain synchronized, without adjusting the microsecond clock us2 in the local clock of the Bluetooth link piconet2, keeping the microsecond clock offset us_offset2 unchanged.

[0025] Optionally, when the Bluetooth slave device switches from the Bluetooth link piconet2 to the listening link, the microsecond clock offset us_offset3 remains unchanged, and when the Bluetooth slave device switches from the listening link to the Bluetooth link piconet2 again, the microsecond clock offset us_offset2 remains unchanged, so that the phase difference between the Bluetooth master device and the source device, the Bluetooth master device and the Bluetooth slave device, and the Bluetooth slave device and the source device is all 625us, and the microsecond clock offsets us_offset1, us_offset2 and us_offset3 are all 625us, aligned according to the Bluetooth time slot.

[0026] Optionally, the Bluetooth master device and the Bluetooth slave device enter and exit the Bluetooth transceiving working state at the same time, and the Bluetooth link switching occurs in the idle time of the Bluetooth non-working state.

[0027] In a second aspect, the present application provides a Bluetooth device for performing the steps in the Bluetooth device multi-link fast switching method as described in one of the first aspects, when the Bluetooth device is in the link communicating with the source device as a Slave role, based on the syncword time difference before and after receiving the packet sent by the source device to adjust the microsecond clock in its local clock, so that its microsecond clock offset remains unchanged, and its local clock remains synchronized with the clock of the source device.

[0028] In a second aspect, the present application provides a Bluetooth audio device multi-link fast switching system, comprising: a source device, a Bluetooth master device and a Bluetooth slave device;

[0029] The source device establishes a Bluetooth link piconet1 with the Bluetooth master device, a listening link between the source device and the Bluetooth slave device, and a Bluetooth link piconet2 between the Bluetooth master device and the Bluetooth slave device;

[0030] When the Bluetooth link piconet1 is running, the Bluetooth master device as Slave role calculates the time difference of syncword between the two times when it receives the packet sent by the source device, and adjusts the microsecond clock in the local clock based on the time difference of syncword, so that the local clock of the Bluetooth master device is synchronized with the clock of the source device, and the microsecond clock offset us_offset1 remains unchanged;

[0031] When the Bluetooth link is running, the Bluetooth slave device as Slave role calculates the time difference of syncword between the two times when it receives the packet sent by the source device, and adjusts the microsecond clock in the local clock based on the time difference of syncword, so that the local clock of the Bluetooth slave device is synchronized with the clock of the source device, and the microsecond clock offset us_offset3 remains unchanged.

[0032] Optionally, when the Bluetooth link piconet2 is running, the Bluetooth master device acts as Master role in the Bluetooth link piconet2, and the Bluetooth slave device acts as Slave role in the Bluetooth link piconet2;

[0033] When the Bluetooth link piconet2 is running, the microsecond clock in the local clock of the Bluetooth master device and the Bluetooth slave device is adjusted at the same time, so that the clock phase difference between the Bluetooth master device and the Bluetooth slave device, between the Bluetooth master device and the source device, and between the Bluetooth slave device and the Bluetooth source device is 625us.

[0034] Optionally, when the Bluetooth link piconet1 is running, the Bluetooth master device calculates the difference clk_adj_us between the microsecond clock offset us_offset1 and 625us;

[0035] When the Bluetooth link piconet2 is running, the Bluetooth master device and the Bluetooth slave device adjust the microsecond clock in their respective local clocks at the same time, and the adjustment value is clk_adj_us, so that the microsecond clock offset us_offset1 remains 625us thereafter.

[0036] Optionally, when the Bluetooth link piconet2 including the Bluetooth master device and the Bluetooth slave device in communication is running, the Bluetooth master device acts as Master role in the Bluetooth link piconet2, and the Bluetooth slave device acts as Slave role in the Bluetooth link piconet2;

[0037] When the Bluetooth link piconet1 is running, the Bluetooth slave device switches from the listening link to the Bluetooth link piconet2, uses the local clock adjusted by the microsecond clock in the local clock based on the syncword time difference on the Bluetooth link piconet1 as the system clock of the Bluetooth link piconet2, and the local clocks of the Bluetooth slave device and the Bluetooth master device remain synchronized, without adjusting the microsecond clock us2 in the local clock of the Bluetooth link piconet2 and keeping the microsecond clock offset us_offset2 unchanged.

[0038] Optionally, when the Bluetooth slave device switches from the Bluetooth link piconet2 to the listening link, the microsecond clock offset us_offset3 remains unchanged; when the Bluetooth slave device switches from the listening link to the Bluetooth link piconet2 again, the microsecond clock offset us_offset2 remains unchanged, so that the phase difference between the Bluetooth master device and the source device, the Bluetooth master and the Bluetooth slave device, and the Bluetooth slave device and the source device is 625us, and the microsecond clock offsets us_offset1, us_offset2 and us_offset3 are all 625us, and the Bluetooth time slots are aligned.

[0039] Optionally, the Bluetooth master device and the Bluetooth slave device enter and exit the Bluetooth transceiving working state at the same time, and the Bluetooth link switching occurs in the idle time of the Bluetooth non-working state.

[0040] Compared with the prior art, the present application has the following beneficial effects:

[0041] In the present application, the device serving as the Slave role in the link communicating with the source device follows the microsecond-level drift of the local clock of the source device in real time based on the syncword time difference when a packet is received, adjusts the microsecond clock part of the local clock in real time, and keeps the microsecond clock offset value us_offset unchanged, so that the time consumption in the link switching process can be significantly reduced, and the communication efficiency and the Bluetooth communication bandwidth can be improved. BRIEF DESCRIPTION OF DRAWINGS

[0042] In order to make the content of the present application more easily and clearly understood, the present application will be further described in detail below according to specific embodiments and in conjunction with the drawings, in which:

[0043] Figure 1 A flowchart of the Bluetooth device multi-link fast switching of an embodiment of the present application;

[0044] Figure 2 A structural schematic diagram of the Bluetooth device multi-link fast switching device of an embodiment of the present application. DETAILED DESCRIPTION

[0045] In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not used to limit the protection scope of the present application.

[0046] The application principles of the present application will be described in detail below with reference to the drawings.

[0047] Embodiment 1

[0048] A method for multi-link fast switching of Bluetooth devices is provided in the embodiments of the present application, as shown in the following steps. Figure 1

[0049] Step (1) calculates the syncword time difference between the time when the device acting as a Slave role in each link for communication with the source device receives the packet sent by the source device and the time when the device acting as a Slave role in each link receives the next packet; the syncword refers to a synchronization word;

[0050] Step (2) adjusts the microsecond clock in the local clock of the device acting as a Slave role in each link based on the syncword time difference, so that the microsecond clock offset of the device acting as a Slave role in each link remains unchanged, and the local clock of the device acting as a Slave role in each link and the clock of the source device remain synchronized.

[0051] According to the method in the embodiments of the present application, the device acting as a Slave role on the Bluetooth link piconet is modified from the original method of keeping the local clock of the device acting as a Slave role synchronized with the clock of the source device by constantly adjusting the microsecond clock offset us_offset obtained on the link, to the method of adjusting the microsecond clock part in the local clock of the device acting as a Slave role according to the syncword time difference between the time when the device acting as a Slave role receives the packet and the time when the device acting as a Slave role receives the next packet, so that the local clock of the device acting as a Slave role is kept synchronized with the clock of the source device, and the microsecond clock offset us_offset remains unchanged. Since the device acting as a Slave role on each link follows the microsecond-level drift of the local clock of the source device in real time when communicating with the source device, and adjusts the microsecond-level value of its own local clock in real time without adjusting the microsecond clock offset relative to the source device, this makes the phase difference of the clock system of each link remain unchanged when the device acting as a Slave role switches between the link for communication with the source device and the link for communication with other devices acting as Slave roles, and the phase difference remains synchronized during the link switching process, thereby significantly reducing the time consumption during the link switching process, improving the communication efficiency and the Bluetooth communication bandwidth.

[0052] ​In one specific mode of the embodiment, the device playing the role of Slave in the link can calculate the syncword time difference according to the two adjacent times of receiving the packet sent by the source device, or calculate the syncword time difference according to the two non-adjacent times of receiving the packet sent by the source device.

[0053] In one specific mode of the embodiment, the device playing the role of Slave in the link (hereinafter referred to as slave device) can calculate the syncword time difference in the following way:

[0054] S001, obtaining the time point t0 at which the slave device receives the syncword in the Nth packet sent by the source device; N is a natural number.

[0055] S002, obtaining the time point t1 at which the slave device receives the syncword in the N+i th packet sent by the source device; i is a positive integer.

[0056] S003, calculating the difference between t1 and t0, and performing modulo operation on the difference between t1 and t0 with respect to the working period of one transceiving packet of the slave device, to obtain the syncword time difference.

[0057] Generally, the working period of one transceiving packet of the Bluetooth device is 1250us. Therefore, the difference between t1 and t0 can be divided by 1250us, and the remainder can be taken as the syncword time difference.

[0058] In one specific mode of the embodiment, when the Bluetooth link piconet1 containing the source device and the Bluetooth master device in communication is running, the source device plays the role of Master in the Bluetooth link piconet1, and the Bluetooth master device plays the role of Slave in the Bluetooth link piconet1.

[0059] In response to the Bluetooth master device receiving the packet sent by the source device in the Bluetooth link piconet1, the Bluetooth master device calculates the syncword time difference between the two times of receiving the packet sent by the source device, and adjusts the microsecond clock us1 in the local clock of the Bluetooth master device based on the syncword time difference, so that the local clock of the Bluetooth master device is synchronized with the clock of the source device, and the microsecond clock offset us_offset1 remains unchanged.

[0060] When the Bluetooth link piconet1 is running, the source device sends packets to the Bluetooth master device, such as sending audio data packets, voice data packets, etc. The Bluetooth slave device establishes a listening link with the source device, and the Bluetooth slave device acts as a Slave role on the listening link; in response to the Bluetooth slave device receiving the source device packets on the listening link, the Bluetooth slave device calculates the syncword time difference between the two times when the Bluetooth slave device receives the source device packets, and adjusts the microsecond clock us3 in the local clock of the Bluetooth slave device based on the syncword time difference, so that the local clock of the Bluetooth slave device is synchronized with the clock of the source device, and the microsecond clock offset us_offset3 remains unchanged.

[0061] In a specific implementation of the embodiment of the application, when the Bluetooth link piconet2 including the Bluetooth master device and the Bluetooth slave device connected in communication is running, the Bluetooth master device acts as a Master role in the Bluetooth link piconet2, and the Bluetooth slave device acts as a Slave role in the Bluetooth link piconet2.

[0062] In response to the Bluetooth master device and the Bluetooth slave device switching to the Bluetooth link piconet2 after the Bluetooth link piconet1 is running, the local clock adjusted by the microsecond clock in the local clock using the syncword time difference on the Bluetooth link piconet1 is used as the system clock of the Bluetooth link piconet2. Since the Bluetooth master device has undergone the adjustment of the microsecond clock us1 on the Bluetooth link piconet1, and the Bluetooth slave device has undergone the adjustment of the microsecond clock us3 on the listening link, the Bluetooth slave device and the Bluetooth master device have both been synchronized with the clock of the source device, and the Bluetooth slave device does not need to adjust the microsecond clock us2 in the local clock on the Bluetooth link piconet2 on the Bluetooth link piconet2, so as to keep the microsecond clock offset us_offset2 unchanged.

[0063] Further, the method in the embodiment of the application also adjusts the us value of the microsecond clock of the local clock native clk of the Bluetooth master device and the Bluetooth slave device on the Bluetooth link piconet2 at the same time, so that the clock phase difference between the Bluetooth master device and the Bluetooth slave device, between the Bluetooth master device and the source device, and between the Bluetooth slave device and the source device is all 625us, that is, the slot unit 625us of the Bluetooth link running.

[0064] In a specific embodiment, on the Bluetooth link piconet1, the difference clk_adj_us between the microsecond clock offset us_offset1 and 625us is obtained by the Bluetooth master device calculation; on the Bluetooth link piconet2, the microsecond clock in the local clock of the Bluetooth master device and the Bluetooth slave device is simultaneously adjusted by clk_adj_us, so that us_offset1 is kept as 625us thereafter. The simultaneous adjustment of the microsecond clock in the local clock of the Bluetooth master device and the Bluetooth slave device can be realized based on the standard procedure defined by the Bluetooth protocol specification.

[0065] When the Bluetooth slave device switches to the listening link again, the microsecond clock offset us_offset3 is kept unchanged, and when the Bluetooth slave device switches to the Bluetooth link piconet2 again, the microsecond clock offset us_offset2 is kept unchanged, so that the phase difference between the Bluetooth master device and the source device, between the Bluetooth master and slave devices, and between the Bluetooth slave device and the source device is 625us, at this time, us_offset1, us_offset2 and us_offset3 are all 625us, and the time slots are aligned. Thus, in the method of the present application, the phase difference of the local clocks between the source device and the Bluetooth master device, between the Bluetooth master and slave devices, and between the source device and the Bluetooth slave device is kept unchanged and can be aligned with the time slots, which can significantly reduce the time consumption in the link switching process and the time consumption caused by the multi-link asynchronous switching, and improve the communication efficiency and the Bluetooth communication bandwidth.

[0066] The method in the embodiment of the present application will be described in detail below in combination with a specific embodiment.

[0067] As shown in Figure 2 The method in the embodiment of the present application is applied to a Bluetooth audio device multi-link fast switching system, which comprises a source device, a Bluetooth master device and a Bluetooth slave device. The Bluetooth master device and the Bluetooth slave device can both be selected as Bluetooth audio devices.

[0068] When the Bluetooth link piconet1 is running, the source device acts as a Master role in the Bluetooth link piconet1, and the Bluetooth master device (repeater) acts as a Slave role in the Bluetooth link piconet1. When the Bluetooth master device receives a packet in the Bluetooth link piconet1, it will usually start the reception hardware configuration in advance for a period of time. Based on the method in the embodiment of the present application, the microsecond clock us1 in the local clock of the Bluetooth master device is adjusted on the Bluetooth link piconet1 by the time difference of the syncword before and after, that is, the microsecond unit value of the local clock of the Bluetooth master device is adjusted each time, and the microsecond clock offset us_offset1 is kept unchanged.

[0069] When the Bluetooth master device switches to the Bluetooth link piconet2 after the operation of the Bluetooth link piconet1 is ended, the Bluetooth master device acts as the Master of the Bluetooth link piconet2, and the Bluetooth slave device acts as the Slave in the Bluetooth link piconet2, and the local clock adjusted by the microsecond clock in the local clock on the Bluetooth link piconet1 is used as the system clock of the Bluetooth link piconet2. When the Bluetooth master device switches to the Bluetooth link piconet1 again, the value of the microsecond clock offset us_offset1 of the Bluetooth master device remains unchanged, so that the Bluetooth master device can save the process of configuring and updating the microsecond clock offset us_offset1 every time in the link switching process, realize the saving of part of the switching time consumption ratio, and achieve the purpose of fast switching.

[0070] When the Bluetooth link piconet1 is running and the audio source device plays music, the Bluetooth master device receives the audio data packet sent by the audio source device, the slave device establishes a listening link with the Bluetooth audio source device, and the Bluetooth slave device (listening node) acts as the Slave on the listening link and receives the audio data packet sent by the audio source device through the listening link. When the Bluetooth slave device receives the packet on the listening link, the receiving hardware configuration is usually started in advance for a period of time. Based on the method in the embodiment of the application, the microsecond clock us3 in the local clock of the Bluetooth slave device is adjusted through the time difference of the syncword of the two times of packet receiving on the listening link, that is, the microsecond unit value of the local clock of the Bluetooth slave device is adjusted each time, and the microsecond clock offset us_offset3 remains unchanged.

[0071] When the Slave in the Bluetooth link piconet2 and the Bluetooth slave device on the listening link are the same device, when the Bluetooth master device switches to the Bluetooth link piconet2 after the operation of the Bluetooth link piconet1 is ended, the Bluetooth master device acts as the Master of the Bluetooth link piconet2, and the Bluetooth slave device acts as the Slave of the Bluetooth link piconet2 when the Bluetooth link piconet1 is switched to the Bluetooth link piconet2 after the operation of the Bluetooth link piconet1 is ended.

[0072] Since the Bluetooth master has made the microsecond clock usl adjustment of the local clock on the Bluetooth link piconetl, and its local clock after the microsecond clock adjustment in the local clock on the Bluetooth link piconetl is taken as the system clock of the Bluetooth link piconet2, and the Bluetooth slave also makes the microsecond clock us3 adjustment of the local clock when listening on the Bluetooth link piconetl, the adjustment of usl and the adjustment of us3 are both based on the adjustment of the source device clock, so that the Bluetooth master and the Bluetooth slave both follow the clock synchronization of the source device, and then when switching to the Bluetooth link piconet2, the clocks of the Bluetooth master and the Bluetooth slave have been kept synchronized, and there is no need to make the us2 adjustment of the Bluetooth link piconet2, so that the effect of keeping the microsecond clock offset us_offset2 unchanged is achieved.

[0073] Further, the method in the embodiment of the application keeps the microsecond clock offset us_offset unchanged, and based on the standard process defined by the Bluetooth protocol specification, simultaneously adjusts the microsecond clock us of the local clock native clk of the Bluetooth master and the Bluetooth slave on the Bluetooth link piconet2, so that the clock phase difference between the Bluetooth master and the Bluetooth slave, between the Bluetooth master and the source device, and between the Bluetooth slave and the Bluetooth source device is all 625us, that is, the slot unit 625us of the Bluetooth link.

[0074] In some specific embodiments, on the Bluetooth link piconetl, the Bluetooth master calculates the difference clk_adj_us between its microsecond clock offset us_offsetl and 625us; and on the Bluetooth link piconet2, based on the standard process defined by the Bluetooth protocol specification, simultaneously adjusts the microsecond clock of the local clock of the Bluetooth master and the Bluetooth slave, and the adjustment value is clk_adj_us, so that us_offsetl keeps 625us thereafter.

[0075] When the Bluetooth slave device switches from the Bluetooth link piconet2 to the listening link again, the value of the microsecond clock offset us_offset3 of the Bluetooth slave device will remain unchanged; when switching from the listening link to the Bluetooth link piconet2 again, the value of the microsecond clock offset us_offset2 will remain unchanged. At this time, us_offset1, us_offset2 and us_offset3 are the same, all being 625us, and the links are aligned in slot units slot, which is an integer multiple of the unit 312.5us of bt_clk_offset. Since the microsecond offset of the slave on each link remains unchanged at this time, the clock offset bt_clk_offset1 of the Bluetooth master device on the Bluetooth link piconet1 relative to the source device, and the clock offset bt_clk_offset3 of the Bluetooth slave device relative to the source device remain unchanged, and the clock offset bt_clk_offset2 of the Bluetooth slave device on the Bluetooth link piconet2 relative to the Bluetooth master device also remains unchanged.

[0076] When the links are aligned in slot units slot, and us_offset1, us_offset2 and us_offset3 are all 625us, the Bluetooth slave device only needs to update the values of bt_clk_offest bt_clk_offset3 and bt_clk_offset2 when switching between the listening link and the Bluetooth link piconet2, and this action of updating us_offset can be omitted in the software, which can save part of the switching time consumption ratio and achieve the purpose of fast switching.

[0077] When the links are aligned in slot units slot, and us_offset1, us_offset2 and us_offset3 are all 625us, and within the Bluetooth idle time before the link switching, the first TX or RX starting point after the Bluetooth master device switches is calculated in advance according to the Bluetooth standard in the software, and the parameters required for hardware TX / RX transmission are configured in advance, so that the switched link can quickly communicate, and the communication efficiency will be greatly improved, basically without wasting any time, achieving piconet switching without time consumption.

[0078] In the specific implementation process, the link types of the Bluetooth link piconet1 and the Bluetooth link piconet2 can be the following two cases: (1) both the Bluetooth link piconet1 and the Bluetooth link piconet2 are classic Bluetooth links; (2) one of them is a classic Bluetooth link and the other is a BLE link.

[0079] Embodiment 2

[0080] The Bluetooth device can be a Bluetooth master device or a Bluetooth slave device; when the Bluetooth master device and the Bluetooth slave device are in a link with a source device as a Slave role, the Bluetooth master device adjusts the microsecond clock in the local clock based on the time difference of the syncword of the two times when the source device sends a packet, so that the microsecond clock offset remains unchanged, and the local clock of the Bluetooth master device is synchronized with the clock of the source device.

[0081] The Bluetooth device can be used to perform the Bluetooth device multi-link fast switching method in embodiment 1, and the specific process is described in other parts of the specification, which will not be repeated here.

[0082] Embodiment 3

[0083] In an embodiment of the application, a Bluetooth audio device multi-link fast switching system is provided, as shown in Figure 2 The source device, the Bluetooth master device and the Bluetooth slave device are provided.

[0084] The source device establishes a Bluetooth link piconet1 with the Bluetooth master device, a listening link between the source device and the Bluetooth slave device, and a Bluetooth link piconet2 between the Bluetooth master device and the Bluetooth slave device.

[0085] When the Bluetooth link piconet1 is running, the Bluetooth master device as a Slave role calculates the time difference of the syncword of the two times when the source device sends a packet, and adjusts the microsecond clock in the local clock based on the time difference of the syncword, so that the local clock of the Bluetooth master device is synchronized with the clock of the source device, and the microsecond clock offset us_offset1 remains unchanged.

[0086] When the listening link is running, the Bluetooth slave device as a Slave role calculates the time difference of the syncword of the two times when the source device sends a packet, and adjusts the microsecond clock in the local clock based on the time difference of the syncword, so that the local clock of the Bluetooth slave device is synchronized with the clock of the source device, and the microsecond clock offset us_offset3 remains unchanged.

[0087] In a specific embodiment of the application, when the Bluetooth link piconet2 is running, the Bluetooth master device is in the Bluetooth link piconet2 as a Master role, and the Bluetooth slave device is in the Bluetooth link piconet2 as a Slave role.

[0088] When the Bluetooth link piconet2 is running, the microsecond clock in the local clock of the Bluetooth master device and the Bluetooth slave device is simultaneously adjusted, so that the clock phase difference between the Bluetooth master device and the Bluetooth slave device, between the Bluetooth master device and the source device, and between the Bluetooth slave device and the source device is all 625us.

[0089] In one specific embodiment of the embodiment of the application, when the Bluetooth link piconet1 is running, the Bluetooth master device calculates the difference clk_adj_us between its microsecond clock offset us_offset1 and 625us;

[0090] When the Bluetooth link piconet2 is running, the Bluetooth master device and the Bluetooth slave device simultaneously adjust the microsecond clock in the local clock, and the adjustment value is clk_adj_us, so that us_offset1 remains 625us thereafter.

[0091] In one specific embodiment of the embodiment of the application, when the Bluetooth link piconet2 including the Bluetooth master device and the Bluetooth slave device in communication is running, the Bluetooth master device acts as a Master role in the Bluetooth link piconet2, and the Bluetooth slave device acts as a Slave role in the Bluetooth link piconet2.

[0092] When the Bluetooth link piconet1 is running, the Bluetooth slave device switches from the listening link to the Bluetooth link piconet2, uses the local clock adjusted by the time difference of the syncword on the Bluetooth link piconet1 as the system clock of the Bluetooth link piconet2, and the local clocks of the Bluetooth slave device and the Bluetooth master device remain synchronized, without adjusting the microsecond clock us2 in the local clock of the Bluetooth link piconet2, and keeping the microsecond clock offset us_offset2 unchanged.

[0093] In one specific embodiment of the embodiment of the application, when the Bluetooth slave device switches from the Bluetooth link piconet2 to the listening link, the microsecond clock offset us_offset3 remains unchanged; when the Bluetooth slave device switches from the listening link to the Bluetooth link piconet2 again, the microsecond clock offset us_offset2 remains unchanged, so that the phase difference between the master device and the source device, between the master and slave devices, and between the Bluetooth slave device and the source device is all 625us, and the microsecond clock offsets us_offset1, us_offset2 and us_offset3 are all 625us, in accordance with the Bluetooth time slot alignment.

[0094] In one specific implementation of the embodiment, the Bluetooth master device and the Bluetooth slave device enter the Bluetooth transceiving working state simultaneously and exit the Bluetooth transceiving working state simultaneously, and the Bluetooth link switching occurs in the idle time of the Bluetooth non-working state.

[0095] The working process of the system in the embodiment will be described in detail below in combination with a specific implementation.

[0096] When the Bluetooth link piconet1 is running, the source device acts as a Master role in the Bluetooth link piconet1, the Bluetooth master device (repeater) acts as a Slave role in the Bluetooth link piconet1, and the Bluetooth master device starts to configure the receiving hardware in advance when receiving a packet in the Bluetooth link piconet1. Based on the method in the embodiment, the microsecond clock us1 in the local clock of the Bluetooth master device is adjusted through the time difference of the syncword before and after the two times on the Bluetooth link piconet1, that is, the microsecond unit value of the local clock of the Bluetooth master device is adjusted each time, and the microsecond clock offset us_offset1 remains unchanged.

[0097] When the Bluetooth master device ends running on the Bluetooth link piconet1 and switches to the Bluetooth link piconet2, the Bluetooth master device acts as a Master of the Bluetooth link piconet2, and the Bluetooth slave device acts as a Slave role in the Bluetooth link piconet2. The local clock adjusted through the microsecond clock in the local clock on the Bluetooth link piconet1 is used as the system clock of the Bluetooth link piconet2. When the Bluetooth master device switches to the Bluetooth link piconet1 again, the value of the microsecond clock offset us_offset1 of the Bluetooth master device remains unchanged. In this way, the Bluetooth master device can save the process of configuring and updating the microsecond clock offset us_offset1 each time in the link switching process, realize the saving of part of the switching time consumption ratio, and achieve the purpose of fast switching.

[0098] When the Bluetooth link piconet1 is running and the audio source device is playing music, the Bluetooth master device receives the audio data packet sent by the audio source device, and the slave device establishes a listening link with the audio source device. The Bluetooth slave device (listening node) acts as a Slave role on the listening link and receives the audio data packet sent by the audio source device through the listening link. When receiving a packet on the listening link, the Bluetooth slave device usually starts to configure the receiving hardware in advance. Based on the method in the embodiment, the microsecond clock us3 in the local clock of the Bluetooth slave device is adjusted through the time difference of the syncword before and after the two times of receiving a packet on the listening link, that is, the microsecond unit value of the local clock of the Bluetooth slave device is adjusted each time, and the microsecond clock offset us_offset3 remains unchanged.

[0099] When the slave in the Bluetooth link piconet2 is the same device as the Bluetooth slave device on the listening link, after the Bluetooth master device runs on the Bluetooth link piconet1 and ends, the Bluetooth master device switches to the Bluetooth link piconet2 as the Master of the Bluetooth link piconet2, and after the Bluetooth slave device runs on the Bluetooth link piconet1 and ends, the Bluetooth slave device switches to the Bluetooth link piconet2 as the Slave of the Bluetooth link piconet2.

[0100] Since the Bluetooth master device has made the microsecond clock us1 adjustment of the local clock on the Bluetooth link piconet1, and the local clock after the microsecond clock adjustment in the local clock is used as the system clock of the Bluetooth link piconet2, and the Bluetooth slave device also makes the microsecond adjustment us3 of the local clock when listening on the Bluetooth link piconet1, the adjustment of us1 and the adjustment of us3 are both based on the adjustment of the source device clock, so that the Bluetooth master device and the Bluetooth slave device are synchronized with the clock of the source device, and then when switching to the Bluetooth link piconet2, the clocks of the Bluetooth master device and the Bluetooth slave device are already synchronized, and there is no need to make the us2 adjustment of the Bluetooth link piconet2, so that the effect of keeping the microsecond clock offset us_offset2 unchanged is achieved.

[0101] Further, the method in the embodiment of the application keeps the microsecond clock offset us_offset unchanged, and based on the standard process defined by the Bluetooth protocol specification, adjusts the microsecond clock us value of the local clock native clk of the Bluetooth master device and the Bluetooth slave device on the Bluetooth link piconet2 at the same time, so that the clock phase difference between the Bluetooth master device and the Bluetooth slave device, between the Bluetooth master device and the source device, and between the Bluetooth slave device and the Bluetooth source device is 625us, that is, the slot unit 625us of the Bluetooth link running.

[0102] In some specific embodiments, on the Bluetooth link piconet1, the Bluetooth master device calculates the difference clk_adj_us between the microsecond clock offset us_offset1 and 625us; on the Bluetooth link piconet2, based on the standard process defined by the Bluetooth protocol specification, the microsecond clock in the local clock of the Bluetooth master device and the Bluetooth slave device is adjusted at the same time, and the adjustment value is clk_adj_us, so that us_offset1 remains 625us thereafter.

[0103] When the Bluetooth slave device switches from the Bluetooth link piconet2 to the listening link again, the value of the microsecond clock offset us_offset3 of the Bluetooth slave device remains unchanged; when it switches from the listening link to the Bluetooth link piconet2 again, the value of the microsecond clock offset us_offset2 remains unchanged. At this time, us_offset1, us_offset2 and us_offset3 are the same, all being 625us, and the links are aligned in slot units slot, which is an integer multiple of the unit 312.5us of bt_clk_offset. Since the microsecond offset of the slave on each link remains unchanged at this time, the clock offset bt_clk_offset1 of the Bluetooth master device on the Bluetooth link piconet1 relative to the source device, and the clock offset bt_clk_offset3 of the Bluetooth slave device relative to the source device remain unchanged, and the clock offset bt_clk_offset2 of the Bluetooth slave device on the Bluetooth link piconet2 relative to the Bluetooth master device also remains unchanged.

[0104] When the links are aligned in slot units slot, and us_offset1, us_offset2 and us_offset3 are all 625us, the Bluetooth slave device only needs to update the values of bt_clk_offest bt_clk_offset3 and bt_clk_offset2 when switching between the listening link and the Bluetooth link piconet2, and this action of updating us_offset can be omitted in the software, which can save part of the switching time consumption ratio and achieve the purpose of fast switching.

[0105] When the links are aligned in slot units slot, and us_offset1, us_offset2 and us_offset3 are all 625us, and during the Bluetooth idle time before the link switching, the first TX or RX starting point after the switching of the Bluetooth master device is calculated in advance according to the Bluetooth standard in the software, and the parameters required for the hardware TX / RX transmission are configured in advance, then the switched link can quickly communicate, and the communication efficiency will be greatly improved, basically without wasting any time, achieving the piconet switching without time consumption.

[0106] In the specific implementation process, the link types of the Bluetooth link piconet1 and the Bluetooth link piconet2 can be the following two cases: (1) both the Bluetooth link piconet1 and the Bluetooth link piconet2 are classic Bluetooth links; (2) one of them is a classic Bluetooth link and the other is a BLE link.

[0107] Those skilled in the art will appreciate that embodiments of the application can be readily used as software, hardware, or a combination of software and hardware. In one

[0108] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 one or more flowcharts and / or blocks can represent code, circuits, hardware components, or executable computer program instructions on a machine-readable or computer-readable storage medium which, when executed by a computer or other Figure 1 an apparatus with a processor-based platform adapted to perform the functions described in a flowchart block(s) or a combination of flowchart blocks.

[0109] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 one or more flowcharts and / or blocks can represent code, circuits, hardware components, or executable computer program instructions on a machine-readable or computer-readable storage medium which, when executed by a computer or other Figure 1 an apparatus with a processor-based platform adapted to perform the functions described in a flowchart block(s) or a combination of flowchart blocks.

[0110] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 one or more flowcharts and / or blocks can represent code, circuits, hardware components, or executable computer program instructions on a machine-readable or computer-readable storage medium which, when executed by a computer or other Figure 1 an apparatus with a processor-based platform adapted to perform the functions described in a flowchart block(s) or a combination of flowchart blocks.

[0111] The embodiments of the application described above are intended to be merely exemplary and those skilled in the art will recognize that many changes can be made to the specific embodiments described which will fall within the scope of the present application as defined by the claims below. The skilled person will readily appreciate that the application is not limited to the embodiments described above, and that modifications and variations can be made without departing from the spirit and scope of the application.

[0112] The above shows and describes the basic principles and main features of the present application and the advantages of the present application. Those skilled in the art should understand that the present application is not limited to the above embodiments, and the above embodiments and descriptions in the specification are only to illustrate the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the claimed present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. A method for fast multi-link switching in a Bluetooth device, characterized in that, include: Calculate the syncword time difference between two consecutive times when the device acting as a Slave receives a packet from the source device in each link used for communication with the source device; Based on the syncword time difference, the microsecond clock in the local clock of the device acting as a slave in each link is adjusted so that the microsecond clock offset of the device acting as a slave in each link remains unchanged, and the local clock of the device acting as a slave in each link is synchronized with the clock of the source device. When the Bluetooth link piconet2, which includes a Bluetooth master device and a Bluetooth slave device that are connected for communication, is running, the Bluetooth master device acts as the Master in the Bluetooth link piconet2, and the Bluetooth slave device acts as the Slave in the Bluetooth link piconet2. When the Bluetooth link piconet2 is running, the microsecond clocks in the local clocks of the Bluetooth master and Bluetooth slave devices are adjusted simultaneously so that the clock phase difference between the Bluetooth master and Bluetooth slave devices, between the Bluetooth master and the source device, and between the Bluetooth slave and the Bluetooth source device is 625µs.

2. The method for fast multi-link switching in a Bluetooth device according to claim 1, characterized in that: When the Bluetooth link piconet1, which includes a source device and a Bluetooth master device, is running, the source device acts as the Master in the Bluetooth link piconet1, and the Bluetooth master device acts as the Slave in the Bluetooth link piconet1. In response to the Bluetooth master device receiving a packet from the source device in the Bluetooth link piconet1, the syncword time difference between the two times the Bluetooth master device receives the packet from the source device is calculated, and the microsecond clock us1 in the local clock of the Bluetooth master device is adjusted based on the syncword time difference, so that the local clock of the Bluetooth master device is synchronized with the clock of the source device, and the microsecond clock offset us_offset1 remains unchanged.

3. The method for fast multi-link switching in a Bluetooth device according to claim 1, characterized in that: When the Bluetooth link piconet1 is running, the difference clk_adj_us between its microsecond clock offset us_offset1 and 625us is calculated by the Bluetooth master device. On the Bluetooth link piconet2, the microsecond clock in the local clocks of both the Bluetooth master and slave devices is adjusted by the value clk_adj_us, so that the microsecond clock offset us_offset1 remains at 625us thereafter.

4. A method for fast multi-link switching in a Bluetooth device according to any one of claims 1 to 3, characterized in that: When the Bluetooth link piconet1 is running, the source device sends packets to the Bluetooth master device, and the Bluetooth slave device establishes a listening link with the source device, with the Bluetooth slave device acting as a slave on the listening link. In response to the Bluetooth slave device receiving a packet from the source device on the listening link, the syncword time difference between the two times the Bluetooth slave device receives the packet from the source device is calculated, and the microsecond clock us3 in the local clock of the Bluetooth slave device is adjusted based on the syncword time difference, so that the local clock of the Bluetooth slave device is synchronized with the clock of the source device, and the microsecond clock offset us_offset3 remains unchanged.

5. A method for fast multi-link switching in a Bluetooth device according to claim 4, characterized in that: When the Bluetooth link piconet2, which includes a Bluetooth master device and a Bluetooth slave device that are connected for communication, is running, the Bluetooth master device acts as the Master in the Bluetooth link piconet2, and the Bluetooth slave device acts as the Slave in the Bluetooth link piconet2. When Bluetooth link piconet1 ends, in response to the Bluetooth slave device switching from the listening link to Bluetooth link piconet2, the local clock adjusted by the microsecond clock in the local clock of Bluetooth link piconet1 using the syncword time difference is used as the system clock of Bluetooth link piconet2. The local clocks of Bluetooth slave device and Bluetooth master device remain synchronized. The microsecond clock us2 in the local clock of Bluetooth link piconet2 is not adjusted, and the microsecond clock offset us_offset2 remains unchanged.

6. A method for fast multi-link switching in a Bluetooth device according to claim 5, characterized in that: When a Bluetooth slave device switches from Bluetooth link piconet2 to the listening link, the microsecond clock offset us_offset3 remains unchanged. When the Bluetooth slave device switches back from the listening link to Bluetooth link piconet2, the microsecond clock offset us_offset2 remains unchanged, ensuring that the phase difference between the Bluetooth master and source devices, the Bluetooth master and slave devices, and the Bluetooth slave and source devices is 625µs, and the microsecond clock offsets us_offset1, us_offset2, and us_offset3 are all 625µs, aligned according to the Bluetooth time slot.

7. A method for fast multi-link switching in a Bluetooth device according to claim 6, characterized in that: The Bluetooth master device and Bluetooth slave device simultaneously enter and exit the Bluetooth transceiver working state, and the Bluetooth link switching occurs during the idle time when the Bluetooth is not in operation.

8. A Bluetooth device, comprising a storage medium and a processor; the storage medium being used to store instructions; the processor being used to execute the steps of the Bluetooth device multi-link fast handover method as described in any one of claims 1 to 7, characterized in that: When the Bluetooth device acts as a slave in the link communicating with the source device, it adjusts the microsecond clock in its local clock based on the time difference between the syncwords before and after receiving a packet from the source device, so that its microsecond clock offset remains unchanged and its local clock is synchronized with the clock of the source device.

9. A multi-link fast switching system for Bluetooth audio devices, characterized in that, include: Source device, Bluetooth master device, and Bluetooth slave device; The source device establishes a Bluetooth link piconet1 with the Bluetooth master device, a listening link is established between the source device and the Bluetooth slave device, and a Bluetooth link piconet2 is established between the Bluetooth master device and the Bluetooth slave device. When the Bluetooth link piconet1 is running, the Bluetooth master device, acting as the Slave, calculates the syncword time difference between the two times it receives the packet from the source device, and adjusts the microsecond clock in its local clock based on the syncword time difference, so that the local clock of the Bluetooth master device is synchronized with the clock of the source device, and keeps the microsecond clock offset us_offset1 unchanged. When the listening link is running, the Bluetooth slave device, acting as the Slave, calculates the syncword time difference between the two times it receives a packet from the source device, and adjusts the microsecond clock in its local clock based on the syncword time difference, so that the local clock of the Bluetooth slave device is synchronized with the clock of the source device, and the microsecond clock offset us_offset3 remains unchanged. When the Bluetooth link piconet2 is running, the Bluetooth master device acts as the Master in the Bluetooth link piconet2, and the Bluetooth slave device acts as the Slave in the Bluetooth link piconet2. When the Bluetooth link piconet2 is running, the microsecond clocks in the local clocks of the Bluetooth master and Bluetooth slave devices are adjusted simultaneously so that the clock phase difference between the Bluetooth master and Bluetooth slave devices, between the Bluetooth master and the source device, and between the Bluetooth slave and the Bluetooth source device is 625µs.

10. A Bluetooth audio device multi-link fast switching system according to claim 9, characterized in that: When the Bluetooth link piconet1 is running, the Bluetooth master device calculates the difference clk_adj_us between its microsecond clock offset us_offset1 and 625us. When the Bluetooth link piconet2 is running, the Bluetooth master device and the Bluetooth slave device simultaneously adjust the microsecond clock in their respective local clocks by the value clk_adj_us, so that the microsecond clock offset us_offset1 remains at 625us thereafter.

11. A Bluetooth audio device multi-link fast switching system according to any one of claims 9 to 10, characterized in that, When the Bluetooth link piconet2, which includes a Bluetooth master device and a Bluetooth slave device that are connected for communication, is running, the Bluetooth master device acts as the Master in the Bluetooth link piconet2, and the Bluetooth slave device acts as the Slave in the Bluetooth link piconet2. When Bluetooth link piconet1 finishes running, the Bluetooth slave device switches from the listening link to Bluetooth link piconet2. It uses the local clock adjusted by using the syncword time difference to adjust the microsecond clock in the local clock of Bluetooth link piconet1 as the system clock of Bluetooth link piconet2. The local clocks of Bluetooth slave device and Bluetooth master device remain synchronized. The microsecond clock us2 in the local clock of Bluetooth link piconet2 is not adjusted, and the microsecond clock offset us_offset2 remains unchanged.

12. A Bluetooth audio device multi-link fast switching system according to claim 11, characterized in that, When a Bluetooth slave device switches from Bluetooth link piconet2 to the listening link, the microsecond clock offset us_offset3 remains unchanged; when the Bluetooth slave device switches back from the listening link to Bluetooth link piconet2, the microsecond clock offset us_offset2 remains unchanged, so that the phase difference between the Bluetooth master and source devices, the Bluetooth master and Bluetooth slave devices, and the Bluetooth slave and source devices is 625us, and the microsecond clock offsets us_offset1, us_offset2, and us_offset3 are all 625us, aligned according to the Bluetooth time slot.

13. A Bluetooth audio device multi-link fast switching system according to claim 12, characterized in that, The Bluetooth master device and Bluetooth slave device simultaneously enter and exit the Bluetooth transceiver working state, and the Bluetooth link switching occurs during the idle time when the Bluetooth is not in operation.

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