Implementation method of bluetooth-based multi-person ad hoc network intercom

Abstract

The application belongs to the technical field of communication, and particularly relates to a kind of implementation methods of multi-person ad hoc network intercom based on Bluetooth, comprising the following steps: initiating a networking request by a networking device; in a broadcast or scanning manner, the networking device sends a broadcast data packet to surrounding devices and continuously scans surrounding devices; screening devices whose parameters meet preset connection conditions as target networking devices; establishing a communication channel connection between the networking device and the target networking device, wherein the communication channel comprises a data transmission channel and a voice transmission channel; using a connection quality evaluation mechanism to evaluate the connection quality of the communication channel, generate an evaluation result, and adjust the connection of networking according to the evaluation result; through innovative device discovery and connection strategy, efficient networking protocol and topology structure, optimized voice transmission quality and dynamic connection management and optimization, the scheme can meet the needs of convenient, efficient and high-quality multi-person real-time intercom.

Description

Technical Field

[0001] This invention belongs to the field of communication technology, specifically relating to a method for implementing multi-user self-organizing network intercom based on Bluetooth. Background Technology

[0002] With social development and technological advancements, people's demand for instant communication is increasing, especially in situations requiring real-time communication such as outdoor activities and group travel. Quickly establishing temporary communication networks has become crucial. Traditional voice communication methods, such as those relying on cellular networks or WiFi, often fail to meet the needs in remote areas, where network coverage is insufficient, or where additional costs are involved. Although walkie-talkies are widely used in various situations due to their portability, they also suffer from drawbacks such as high power consumption, poor sound quality, and only supporting half-duplex communication, affecting the user experience.

[0003] Bluetooth technology has been widely used in short-range communication due to its advantages such as low power consumption and low cost. However, existing Bluetooth intercom solutions still have significant shortcomings in group intercom applications:

[0004] Traditional Bluetooth intercom solutions face a series of technical challenges in practical applications that hinder their widespread and efficient use. The device pairing process is cumbersome and complex, relying entirely on manual user operation, requiring repeated pairing before each use. Furthermore, once paired, the devices in traditional Bluetooth intercom solutions have fixed locations, leading to slow routing when devices or their locations change, making them unsuitable for dynamically changing scenarios. The networking capability of traditional Bluetooth intercom solutions is typically limited to two users, failing to meet the needs of multi-user networking. Finally, the voice transmission quality of traditional Bluetooth intercom solutions is poor, exhibiting unclear voice and high latency, negatively impacting user experience.

[0005] In summary, existing Bluetooth intercom technologies suffer from problems such as cumbersome pairing processes, fixed device locations, limited networking capabilities, and poor voice transmission quality. These issues restrict the application of Bluetooth technology in multi-person real-time intercom scenarios. Current Bluetooth voice intercom technologies cannot adequately meet users' needs for convenient, efficient, and high-quality multi-person real-time intercom communication in various scenarios. Therefore, there is an urgent need to provide a Bluetooth-based multi-person self-organizing network intercom implementation method that can satisfy the requirements for convenient, efficient, and high-quality multi-person real-time intercom communication. Summary of the Invention

[0006] To address the aforementioned technical problems, this invention provides a method for implementing multi-person self-organizing network intercom based on Bluetooth, which can meet the needs of convenient, efficient, and high-quality real-time intercom communication among multiple people.

[0007] The technical solution adopted in this invention is as follows: A method for implementing multi-user self-organizing network intercom based on Bluetooth, comprising the following steps:

[0008] The device to be networked initiates a network formation request;

[0009] The device to be networked sends broadcast data packets to surrounding devices and continuously scans for surrounding devices, using either broadcast or scanning methods.

[0010] Select devices in the surrounding network whose parameters meet the preset connection conditions as target networking devices;

[0011] Establish a communication channel connection between the device to be networked and the target device, wherein the communication channel includes a data transmission channel and a voice transmission channel;

[0012] A connection quality assessment mechanism is used to assess the connection quality of the communication channel, generate assessment results, and adjust the network connection based on the assessment results.

[0013] Furthermore, the connection process of the communication channel includes the following steps:

[0014] Initiate a data transmission channel connection request to establish multiple data transmission channel connections between the device to be networked and the target device;

[0015] Complete the exchange of network information;

[0016] Initiate voice transmission channel connections to establish multiple voice transmission channel connections between the device to be networked and the target device.

[0017] Furthermore, the networking method includes serial networking, and the networking information of the serial networking includes head device, intermediate device, tail device, the position of each device in the network, the number of devices in the network, and the list of device addresses in the network. There are several intermediate devices and they are located between the head device and the tail device.

[0018] The information synchronization of the serial network includes the following steps:

[0019] The target networking device that successfully connects to the device to be networked is the newly added device. The newly added device is then connected to the serial network group. The newly added device simultaneously sends link update requests to the preceding device and the following device until the preceding device receives the link update request.

[0020] The head device initiates a network information synchronization command, which is transmitted sequentially from the head device to the tail device.

[0021] After receiving the network information synchronization command, the tail device starts from the tail device. Each intermediate device before the tail device replies to the previous intermediate device and sends a response data packet.

[0022] The head device receives response data packets from the intermediate and tail devices, integrates them, generates summary information, and transmits the integrated summary information to the entire serial network.

[0023] After the network information transmission is completed, the head device and the tail device respectively obtain identifiers.

[0024] Furthermore, the networking method also includes tree networking, and the networking information of the tree networking includes root node device, stem node device, leaf node device, number of devices in the network, and list of device addresses in the network;

[0025] The information synchronization of the tree-shaped network includes the following steps:

[0026] After a node device scans and finds the target networking device, it connects the target networking device as a new device to the tree network group and sends a link change notification to the root node device.

[0027] When the root node device receives a link change notification, it initiates a network information synchronization request, which is then passed down from the root node to each node device.

[0028] Each node device receives the network information synchronization request and replies with confirmation information from the root node device.

[0029] Furthermore, both the serial network group and the tree network group are equipped with a retransmission mechanism, which is as follows:

[0030] The system determines whether the data packet sending device receives a response from the data packet receiving device within a preset response time after sending the data packet. If not, the data packet sending device will retransmit the packet.

[0031] Furthermore, the connection quality assessment mechanism includes the following steps:

[0032] The system acquires the signal strength between each device in the network in real time, determines whether the signal strength between each device in the network is lower than the preset signal strength threshold, and if so, triggers the reconnection mechanism and reselects the connection path.

[0033] Real-time acquisition of packet loss rate between upstream network devices and corresponding network devices of each network device;

[0034] Determine whether the packet loss rate between the upstream network device and the corresponding network device of each network device in the network is greater than the preset disconnection threshold. If so, disconnect the network device from the corresponding upstream network device and trigger reconnection.

[0035] Determine whether the packet loss rate between the upstream network device and the corresponding network device of each network device in the network is greater than the preset mute threshold and less than or equal to the preset disconnection threshold. If so, control the corresponding network device to perform mute processing.

[0036] Determine whether the packet loss rate between the upstream network device and the corresponding network device of each network device in the network is greater than the preset relay threshold and less than or equal to the preset mute threshold. If so, control the network device to stop forwarding the data received from the corresponding upstream network device.

[0037] Furthermore, the broadcast or scanning uses Bluetooth Low Energy broadcast or scanning mechanism to discover each device, the data transmission channel uses asynchronous connectionless link to transmit networking information, and the voice transmission channel uses synchronous connection guided link, enhanced synchronous connection guided link or isochronous channel to transmit voice data in real time.

[0038] Furthermore, it also includes processing the voice data of the voice transmission channel. The process of processing the voice data includes:

[0039] The device to be networked collects voice data from the target network device that has successfully connected to it through the voice transmission channel, and simultaneously collects voice data from the local microphone of each device.

[0040] The VAD algorithm and volume detection are used to detect the voice data of the target networking device that has successfully connected to the network and the corresponding local MIC voice data, and to filter out the valid voice data.

[0041] The effective speech data is mixed to generate mixed effective speech data;

[0042] The mixed and valid voice data is encoded and sent to the target networking device that is already connected to the device to be networked.

[0043] The beneficial effects of this invention are:

[0044] 1. The device to be networked actively initiates a network request, simplifying user operations and eliminating the need for manual settings. Automated broadcasting and scanning enable devices to quickly discover available surrounding devices, reducing the time and cost of manual searching and pairing. Based on preset connection conditions, it filters out target network devices whose parameters match the preset connection criteria, ensuring the selection of the most suitable network device and improving network efficiency and reliability. Dedicated data transmission and voice transmission channels are established, allowing for the separate processing of different types of information, optimizing information transmission efficiency, reducing latency and interference. Real-time monitoring of network status and dynamic adjustment of network connections ensure optimal communication quality even in complex and changing environments.

[0045] 2. Utilizing Bluetooth Low Energy's broadcast or scanning mechanism, the device automatically discovers and connects to other devices without the need for a complex pairing process. When the device's location changes, the connection path can be dynamically adjusted to ensure a stable connection even after the device's location changes. Compared with traditional Bluetooth pairing methods, this method is not strictly limited by the device's location, improving flexibility and ease of use.

[0046] 3. This invention not only supports serial networking (head device, intermediate device, tail device), but also tree networking (root node device, stem node device, leaf node device). It can flexibly select the most suitable network structure according to the actual application scenario, with strong networking flexibility, supporting multiple topologies to meet the needs of different scenarios. The device positions can be changed at will to meet the needs of different application scenarios.

[0047] 4. Enables full-duplex real-time intercom, with communication efficiency and user experience superior to half-duplex walkie-talkies. By establishing multiple data transmission channels and voice transmission channels, it supports full-duplex real-time intercom, allowing each device to send and receive voice simultaneously, ensuring efficient real-time communication.

[0048] 5. A dedicated voice transmission channel, combined with noise reduction, echo cancellation, VAD (Voice Activity Detection), and volume detection technologies, ensures low-latency and high-definition voice communication. Effective filtering and mixing of voice data further enhances voice quality, generating clear and coherent mixed voice data from various devices, ensuring that the voices of all participants can be heard clearly.

[0049] 6. By monitoring parameters such as signal strength and packet loss rate between devices in real time, the system dynamically adjusts connection paths to ensure network stability and efficient operation. When device locations change or devices join / leave the network, the system can automatically adjust connections to ensure network stability and scalability. A retransmission mechanism ensures reliability; if a network device does not receive a response within a preset response time, it retransmits the data packet to ensure data transmission reliability and reduce data loss due to network instability. Attached Figure Description

[0050] Figure 1 A flowchart illustrating the implementation method of Bluetooth-based multi-user self-organizing network intercom provided in the embodiments of this application;

[0051] Figure 2 A schematic diagram of the serial networking network topology in the Bluetooth-based multi-person self-organizing network intercom implementation method provided in the embodiments of this application;

[0052] Figure 3 A schematic diagram of the tree-shaped network topology in the Bluetooth-based multi-person self-organizing network intercom implementation method provided in the embodiments of this application;

[0053] Figure 4 The diagram shows the logic block diagram of the audio mixing logic in the Bluetooth-based multi-user self-organizing network intercom implementation method provided in the embodiments of this application. Detailed Implementation

[0054] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and should not be construed as limiting the scope of the invention.

[0055] like Figures 1-4 As shown, a method for implementing a Bluetooth-based multi-user self-organizing network intercom is as follows: Figure 1 As shown, it includes the following steps:

[0056] The device to be networked initiates a network formation request;

[0057] The device to be networked sends broadcast data packets to surrounding devices and continuously scans for surrounding devices, using either broadcast or scanning methods.

[0058] In this embodiment, device discovery is achieved using Bluetooth Low Energy (BLE) broadcast or scanning mechanisms. After a device initiates network formation, it continuously broadcasts information about itself and its status to surrounding devices at fixed 32-millisecond intervals. The broadcast data packets include the following:

[0059] Device address: Assigned by the Bluetooth Special Interest Group (SIG) and used as a unique identifier for the device;

[0060] Signal strength: The strength of the communication signal between two networked devices, used to determine the distance between the devices;

[0061] Manufacturer Identifier: The device manufacturer identifier is used to distinguish the manufacturer;

[0062] Manufacturer ID: Identifies the manufacturer;

[0063] Product ID: Defined according to product model;

[0064] Network ID: Randomly assigned during network setup; only networks with the same ID can interconnect.

[0065] Peer device address: The address of the peer device in one of the networking modes;

[0066] Busy sign: Indicates whether the device is currently busy;

[0067] Number of users in the network: This indicates the number of users currently in the network.

[0068] Connected device status: storage data channel connection status and voice channel connection status.

[0069] Select devices in the surrounding network whose parameters meet the preset connection conditions as target networking devices;

[0070] In this embodiment, the device continuously scans for broadcast signals from surrounding devices while broadcasting. It continuously scans for surrounding devices and filters them based on factors such as signal strength, prioritizing devices with strong signals that meet the rules. Then, it filters the broadcast packets it has scanned to improve the detection efficiency.

[0071] The parameters include: signal strength, broadcast packet length, vendor identifier, vendor ID, network ID, Busy flag, number of devices in the group, and number of empty slots in the connected device list.

[0072] Preset connection conditions include:

[0073] The signal strength of the target networking device is greater than the connection signal strength threshold of -75dBm;

[0074] The broadcast packet length, vendor identifier, vendor ID, and network ID of the target networking device and the device to be networked are all equal;

[0075] If the target networking device does not have the Busy flag, it means that the target networking device is not busy. Avoid connecting two or more devices to each other, which may lead to connection failure and waste time.

[0076] With 8 or fewer devices in a group, the number of connected devices can be flexibly controlled to improve the user experience.

[0077] The number of empty slots in the connected device list is greater than 0, and each device can directly connect to 3 devices.

[0078] Additionally, if the address of the peer device is greater than that of the device itself, it waits for the peer device to initiate a connection and does not initiate a connection itself.

[0079] Establish a communication channel connection between the device to be networked and the target device, wherein the communication channel includes a data transmission channel and a voice transmission channel;

[0080] Specifically, the connection process of the communication channel includes the following steps:

[0081] Initiate a data transmission channel connection request to establish multiple data transmission channel connections between the device to be networked and the target device to complete the exchange of network information;

[0082] Initiating a voice transmission channel connection establishes multiple voice transmission channel connections between the device to be networked and the target device. In this embodiment, the data transmission channel and the voice transmission channel are completely independent. The data transmission channel is established first for network information transmission. Only after this is completed is the voice transmission channel established. A data transmission channel connection request is initiated to the target device to establish multiple data transmission channel connections between the device to be networked and the target device for network exchange. After the network information exchange is completed, a voice transmission channel connection is initiated to the target device to establish the voice transmission channel between the device to be networked and the target device. By establishing the data transmission channel first and ensuring its stability and reliability before establishing the voice transmission channel, the success of each stage can be verified step by step, reducing potential problems when establishing complex connections all at once. By establishing the data transmission channel first, network information exchange and synchronization can be completed quickly, accelerating the overall network construction speed and shortening user waiting time. Based on the feedback information provided by the data transmission channel (such as signal strength, packet loss rate, etc.), the system can dynamically adjust the relevant parameters of the voice transmission channel to adapt to the current network conditions, further improving communication efficiency.

[0083] In this embodiment, each device can establish multiple data transmission channels and voice transmission channels. The system also includes connection list management: after the scanning conditions are met, the found device information is added to the connectable list, and the data channel connection function is called to initiate a connection. The device information includes: peer address, signal strength, device data channel, voice channel status, total number of devices in the group, and its position within the group.

[0084] If the current device is not in a connected state, disconnected state, or not updating the network information list, and the target device is not connected, initiate a data transmission channel connection.

[0085] During the connection initiation process, the device will stop broadcasting and scanning to ensure connection speed and success rate.

[0086] After receiving the connection request, the device responds to the request and establishes a data channel connection.

[0087] The device will update its broadcast information in real time based on the current connection status and number of connections, and will restart the broadcast once the connection is completed.

[0088] After the data transmission channel connection is completed and the network information is transmitted, the device that initiated the data channel connection will initiate the voice transmission channel connection again.

[0089] A connection quality assessment mechanism is used to assess the connection quality of the communication channel, generate assessment results, and adjust the network connection based on the assessment results.

[0090] In this embodiment, as Figure 2As shown, the networking method includes serial networking. The networking information of the serial networking includes head device, intermediate device, tail device, the position of each device in the network, the number of devices in the network, and the list of device addresses in the network. There are several intermediate devices, which are located between the head device and the tail device.

[0091] The information synchronization of the serial network includes the following steps:

[0092] The target networking device that successfully connects to the device to be networked is the newly added device. The newly added device is then connected to the serial network group. The newly added device simultaneously sends link update requests to the preceding device and the following device until the preceding device receives the link update request.

[0093] The head device initiates a network information synchronization command, which is transmitted sequentially from the head device to the tail device.

[0094] After receiving the network information synchronization command, the tail device starts from the tail device. Each intermediate device before the tail device replies to the previous intermediate device and sends a response data packet.

[0095] In this embodiment, the response data packet contains information such as the address of the corresponding device and its location in the network.

[0096] The head device receives response data packets from the intermediate and tail devices, integrates them, generates summary information, and transmits the integrated summary information to the entire serial network.

[0097] By following the steps above, the information transmission of each device can be synchronized to the intermediate devices and the head device. Finally, after the head device receives all the information, it will perform a data distribution to transmit the summarized information to the entire network.

[0098] After the network information transmission is completed, the head device and the tail device respectively obtain identifiers.

[0099] In this embodiment, the head device and tail device obtain the identifiers Token_Head and Token_tail, respectively, to identify the head device and tail device. The head device and tail device will simultaneously start broadcasting and scanning to connect to new devices.

[0100] After the network information is transmitted, the devices in the network will announce the information via voice, and will also start broadcasting and scanning, depending on their location and number of connections.

[0101] In this embodiment, a custom lightweight protocol is used for networking to reduce communication overhead and complexity. The lightweight protocol includes operations such as device joining, leaving, and status updates to ensure dynamic adjustment of the network structure.

[0102] As a preferred option, such as Figure 3 As shown, the networking method also includes tree networking, and the information transmission of tree networking uses a data transmission channel to transmit networking information.

[0103] In a tree-structured network, there are three roles: root node, stem node, and leaf node. The root node is the starting node of the tree network and is responsible for initiating network information synchronization requests during network setup. The stem node is the intermediate node connecting the root node and the leaf nodes and is responsible for forwarding network information and voice data. The leaf node is the ending node of the tree network and is usually not directly connected to other leaf nodes, but only to the stem node or the root node.

[0104] The networking information for a tree-structured network includes the following:

[0105] Node role: Identifies whether the node is a root node, stem node, or leaf node;

[0106] Number of devices that have completed network setup: The number of devices that have successfully joined the current network.

[0107] Device addresses within the network: A list of Bluetooth addresses for all devices on the network.

[0108] In a tree-structured network, the root node initiates the last link. The root node is responsible for initiating network information synchronization requests, ensuring information consistency and up-to-dateness across the entire network. The root node sends these requests to the next lower-level nodes via data transmission channels (such as ACL links).

[0109] The transmission path is hierarchical, specifically from the root node to the stem node, and then to the leaf node. The specific path is: root node -> stem node -> leaf node. Each node, upon receiving the network topology information, will pass the information to its next-level node, until it reaches the final leaf node.

[0110] After receiving the information synchronization request from the root node, each node needs to reply to the root node to confirm that it has received and processed the network information. If a node fails to reply in a timely manner or its reply is lost for other reasons, the root node will resend the request to ensure that all nodes receive the latest network information.

[0111] If a node loses connection to a device, it will proactively send a link change notification to the root node. Upon receiving the link change notification, the root node will re-initiate a network information synchronization request to synchronize the latest network information to all nodes, ensuring real-time updates and consistency of the network structure.

[0112] Specifically, the information synchronization of the tree-shaped network includes the following steps:

[0113] After a node device scans and finds the target networking device, it connects the target networking device as a new device to the tree network group and sends a link change notification to the root node device.

[0114] When the root node device receives a link change notification, it initiates a network information synchronization request. The network information synchronization request is passed from the root node to the stem node device and the leaf node device.

[0115] Each node device receives the network information synchronization request and replies with confirmation information to the root node device. The root node device ensures that the information is successfully transmitted.

[0116] If the connection status of a node device changes (new connection or disconnection), the node will proactively send a link change notification to the root node.

[0117] After receiving the link change notification, the root node re-initiates the network information synchronization request to synchronize the latest network information to each node.

[0118] As a preferred embodiment, both the serial network and the tree network are equipped with a retransmission mechanism, which is as follows:

[0119] The system determines whether a response is received from the data packet receiving device within a preset response time after the data packet sending device sends the data packet. If not, the data packet sending device retransmits the packet. In this embodiment, the data packet sending device sends data packets to the data packet receiving device. Each data packet typically has a unique sequence number or ID so that the receiver can identify and acknowledge a specific data packet. After receiving the data packet, the data packet receiving device checks it. If the data packet is correct, the data packet receiving device generates an ACK message and sends it back to the data packet sending device to confirm that the data packet has been successfully received. The ACK message usually contains the sequence number or ID of the acknowledged data packet, so the sender can clearly know which data packet has been successfully received. After sending the data packet, the data packet sending device starts a timer to wait for the ACK response from the data packet receiving device. The data packet sending device retransmits twice. Specifically, if the data packet sending device does not receive the response within the preset response time (135ms), it considers the data packet lost or the reception to have failed, triggering the first retransmission. The retransmission restarts the timer, and if it times out again, a second retransmission is performed. If no ACK response is received after the second retransmission, the data packet may be marked as unreachable or other error handling logic may be executed. If the set number of retransmissions (2) is exceeded, retransmission will not be attempted further. Excessive attempts can cause link congestion, making it difficult for the receiving device to receive data. If the device has exhausted its retransmission limit without completing data transmission, it will actively disconnect. Additionally, if the receiving device receives a data packet but replies with an error message, it will handle the error according to the corresponding error code, such as retransmitting or performing other operations.

[0120] As a preferred embodiment, the connection quality assessment mechanism includes the following steps:

[0121] The system acquires the signal strength between each device in the network in real time, determines whether the signal strength between each device in the network is lower than the preset signal strength threshold, and if so, triggers the reconnection mechanism and reselects the connection path.

[0122] In this embodiment, the signal strength between each network device is acquired in real time, and a filtering algorithm is used for linear operation to ensure the accuracy of the signal strength. The preset signal strength threshold is -75dBm. When the signal strength between devices is lower than -75dBm, the device with poor link quality is disconnected and a new device is connected to optimize communication performance.

[0123] Real-time acquisition of packet loss rates between upstream network devices and corresponding network devices for each network device within the network;

[0124] Determine whether the packet loss rate between the upstream network device and the corresponding network device of each network device in the network is greater than the preset disconnection threshold. If so, disconnect the network device from the corresponding upstream network device and trigger reconnection.

[0125] Determine whether the packet loss rate between the upstream network device and the corresponding network device of each network device in the network is greater than the preset mute threshold and less than or equal to the preset disconnection threshold. If so, control the corresponding network device to perform mute processing.

[0126] Determine whether the packet loss rate between the upstream network device and the corresponding network device of each network device in the network is greater than the preset relay threshold and less than or equal to the preset mute threshold. If so, control the network device to stop forwarding the data received from the corresponding upstream network device.

[0127] The specific rules for handling packet loss rate of network devices are as follows: (e.g.) Figure 2 As shown in the example of serial networking: Device A -> Device B -> Device C -> Device D)

[0128] The disconnection threshold (70%) handling logic is as follows: When a network device detects that the packet loss rate between itself and its directly connected upstream network device is greater than 70%, then:

[0129] The networking device directly disconnects from the upstream networking device and triggers the reconnection mechanism, broadcasting its own information and scanning for surrounding devices to reconnect.

[0130] The logic for handling the silence threshold (50%) is as follows: When a network device detects a packet loss rate between itself and its directly connected upstream network device that is greater than 50% and less than or equal to 70% (e.g., Figure 2As shown, device B detects the packet loss rate between device A and device B, and device C detects the packet loss rate between device B and device C. The specific process of controlling the corresponding network devices to perform silent processing is as follows:

[0131] (1) Mute immediately: Stop playing audio data from this upstream source;

[0132] (2) Block forwarding: Stop transmitting data from the upstream to the downstream (e.g., Figure 2 As shown, when device B determines that the data packet loss rate from device A is greater than 50% and less than or equal to 70%, device B will discard the data transmitted from device A and will not forward the data transmitted from device A to device B to device C.

[0133] (3) Local data independence: The audio data collected by the network devices themselves (such as MIC input) can still be forwarded to downstream devices normally (such as the MIC data of device B can still be transmitted to device C).

[0134] The relay threshold (40%) processing logic is as follows: When a network device detects that the packet loss rate between itself and its directly connected upstream network device is greater than 40% and less than or equal to 50%, then:

[0135] (1) Continue playback: Play audio from the upstream network device normally;

[0136] (2) Stop relay: Only block the forwarding of data from upstream network devices of this network device (e.g., Figure 2 As shown, device B can still play the audio transmitted from device A to device B, but it stops forwarding the data transmitted from device A to device B to device C.

[0137] (3) Mixed forwarding: Audio collected by the network devices themselves (such as MIC input) can be mixed with other normal link data and sent down.

[0138] Normal transmission logic: When a network device detects that the packet loss rate between itself and its directly connected upstream network device is less than or equal to 40%:

[0139] (1) Continuously play audio data from upstream networking devices;

[0140] (2) Completely forward data from upstream networking devices and this networking device to downstream networking devices.

[0141] In this embodiment, three different thresholds are set to reduce noise interference and improve call clarity.

[0142] In this embodiment, the reconnection mechanism is as follows: the device to be networked analyzes the location of surrounding target network devices based on signal strength and adjusts the network connection path.

[0143] In this embodiment, when the device location changes or a device joins / leaves the network, the device detects the location change based on the signal strength change and dynamically adjusts the network connection path. Specifically, it disconnects devices with a signal strength less than -75dBm and connects devices with a signal strength greater than or equal to -75dBm.

[0144] After the device connection is completed, it continues to broadcast or scan. If its own voice quality is poor (judged based on signal strength and packet loss rate) and there are closer devices nearby, it will actively disconnect the inferior link and connect to the new device.

[0145] A connection quality assessment mechanism is introduced to dynamically adjust the network and ensure user experience. Theoretically, there is no upper limit to the number of devices, but considering real-time voice communication and user experience, the maximum is generally limited to 16. When the maximum number of connected devices is reached, the network can still broadcast or scan to find new connection opportunities. Specifically, after performing a link quality assessment, connection adjustments occur in two ways: if the link quality is too poor (signal strength less than -75dBm), the connection is disconnected, triggering a reconnection; if the current link quality is not good enough (signal strength less than -75dBm) and there are other connectable devices nearby, the current connection is disconnected to connect to the discovered connectable device.

[0146] In this embodiment, the connection quality assessment mechanism also includes a packet loss prediction mechanism, used to continuously observe transmitted and received data and predict packet loss. The packet loss prediction mechanism includes the following steps:

[0147] Obtain the data packet reception interval within the network;

[0148] Determine whether the data packet reception interval is greater than the preset normal reception interval threshold; if so, it is determined to be a delayed data packet.

[0149] Using 10 consecutive data packets as an observation window, the trend of delayed data packet quantity and reception interval is analyzed, and packet loss prediction results are generated.

[0150] Specifically, the prediction process of the packet loss prediction mechanism is as follows:

[0151] At the receiving end of the device, the timestamp of each voice data packet is recorded, and the transmission delay of the data packet is calculated.

[0152] Specifically, the system presets a normal data packet reception timestamp of 7.5ms (normal reception interval threshold) to receive a data packet at regular intervals. If the packet reception interval is greater than 7.5ms, it indicates that the data packet is delayed.

[0153] Observe changes in data packet transmission delay to predict potential packet loss. If the transmission delay of multiple consecutive data packets increases significantly, packet loss is predicted, indicating a deterioration in link quality. Specifically, the system predicts a deterioration in link quality when any of the following conditions are met:

[0154] Within an observation window consisting of 10 consecutive data packets, the number of data packets N≥7 with a reception interval ΔT>7.5ms;

[0155] Within an observation window consisting of 10 consecutive data packets, the sequence of data packet reception intervals exhibits a monotonically increasing trend (e.g., the first packet reception delay is 1ms, and the 7th packet reception delay is 3ms).

[0156] If the data packet transmission delay is relatively stable, the predicted link quality is good. Specifically, the system predicts excellent link quality if and only if the following two core conditions are met simultaneously:

[0157] Within an observation window consisting of 10 consecutive data packets, the number n of all data packets with a reception interval ΔT > 7.5 ms satisfies n ≤ 6;

[0158] Within an observation window consisting of 10 consecutive data packets, the sequence of data packet reception intervals does not exhibit a monotonically increasing trend.

[0159] If potential packet loss is predicted, a mechanism can be triggered in advance to find a connectable device and disconnect the current link, minimizing noise for the user and ensuring a good user experience.

[0160] As a preferred embodiment, the data transmission channel connection uses an asynchronous connection-guided link to transmit network information, and the voice transmission channel connection uses a synchronous connection-guided link or an enhanced synchronous connection-guided link to transmit voice data in real time.

[0161] As a preferred embodiment, the method also includes processing the voice data of the voice transmission channel. The process of processing the voice data includes:

[0162] Each device collects voice data from other devices through the voice transmission channel, and simultaneously collects voice data from the local microphone of each device;

[0163] Specifically, the voice transmission channel uses SCO (Synchronous Connection Guided Link), eSCO (Enhanced Synchronous Connection Guided Link), or ISOC (Isochronous Channel) to transmit voice data in real time. These links provide synchronous connection guided services to achieve high-quality real-time voice transmission. Among them, the SCO link provides basic real-time voice transmission, the eSCO link supports higher data rates and more reliable transmission with error correction functions, and ISOC, introduced in Bluetooth 5.2 and later versions, is designed for low-latency, high-throughput audio streaming and is very suitable for real-time voice communication between multiple devices.

[0164] In this embodiment, the voice quality is improved through the following steps:

[0165] 1. Local buffering eliminates network transmission jitter and latency, ensuring voice quality:

[0166] (1) The sending and receiving ends set up voice buffers to temporarily store a certain number of frames (e.g., 5 frames) of voice data. Jitter in network transmission can cause uneven arrival times of voice data packets. Local buffers can smooth out these jitters and ensure that voice data is sent and played at uniform intervals. By pre-storing a certain amount of voice data, local buffers can reduce voice playback interruptions caused by network latency.

[0167] (2) Transmitter Buffer: The voice data is divided into fixed-size data packets, each containing a certain duration of voice data (7.5ms). A buffer is set up at the transmitting end to store the data packets sequentially. The transmission rate of the data packets is controlled based on network conditions and feedback from the receiving end to ensure that the data packets can be smoothly transmitted to the receiving end.

[0168] (3) Receiver Buffer: The receiver receives data packets from the network and stores them in a buffer. Since network transmission may result in inconsistent packet arrival order, the receiver needs to sort the packets according to their sequence numbers to ensure correct playback of the voice data. The playback rate of the voice data is controlled based on the amount of data in the buffer and network conditions to ensure smooth voice playback.

[0169] 2. The receiving end effectively improves voice quality during packet loss through packet loss compensation:

[0170] (1) At the receiving end, when data packet loss is detected, the lost data packets are compensated using certain algorithms and techniques to reduce the impact of packet loss on voice quality. By compensating for lost data packets, interruptions and stuttering during voice playback are reduced. Through the compensation algorithm, lost voice data is recovered, improving the clarity and intelligibility of the voice.

[0171] (2) Similar to packet loss detection, each data packet is sent with a sequence number. The receiving end determines whether a data packet has been lost by detecting the continuity of the sequence numbers. When a data packet loss is detected, the voice data in the lost data packet can be obtained by linear interpolation of the voice data in the two previously received data packets.

[0172] (3) Adjust the parameters of the compensation algorithm according to the packet loss rate to achieve the best compensation effect.

[0173] (4) In some cases, if the voice data in the lost data packets is noise, audio data similar to the background noise can be generated to replace the voice data in the lost data packets. This method can reduce the abruptness of the sound caused by packet loss.

[0174] After the audio is captured by the MIC (microphone), the noise reduction module first removes wind noise and environmental noise interference while preserving human voice. At the same time, echo cancellation technology is also used to avoid echoing and ensure good voice performance in complex environments.

[0175] The VAD algorithm and volume detection are used to detect voice data collected from other devices and local microphones through the voice transmission channel, and to filter valid voice data. The detection results are represented as Boolean values ​​(True / False) and stored in the corresponding data structure to determine whether each data source contains valid voice.

[0176] Specifically, the VAD algorithm (Voice Activity Detection algorithm) and volume detection are used to detect in real time whether each data source contains valid voice. First, the VAD algorithm is used to detect whether the voice data contains human speech. Then, the volume detection is used to determine whether the volume of the voice data reaches the preset volume threshold. If so, it is determined to be valid voice data. If there is no valid voice, no mixing or empty data is transmitted to the next device.

[0177] The valid speech data is mixed to generate mixed valid speech data; specifically, the mixing process is as follows:

[0178] The device to be networked collects voice data from the target network device that has successfully connected to it through the voice transmission channel, and simultaneously collects voice data from the local microphone of each device.

[0179] The VAD algorithm and volume detection are used to detect the voice data of the target networking device that has successfully connected to the network and the corresponding local MIC voice data, and to filter out the valid voice data.

[0180] The effective speech data is mixed to generate mixed effective speech data;

[0181] The mixed and valid voice data is encoded and sent to the target networking device that is already connected to the device to be networked.

[0182] like Figure 4As shown, in this embodiment, the mixing coefficient depends on how many devices the device to be networked is connected to and whether the voice data is valid. For example, device D (the device to be networked) is connected to three devices, plus its own MIC data, resulting in four voice data points. The validity of each of these four voice data points is then determined, and the mixed voice data is sent to devices A, B, and C respectively. Data sent to device A cannot be mixed with data from device A. If all voice data are valid, the mixed voice data sent to device A consists of voice data from device B, voice data from device C, and MIC data from device D. The same logic applies to the mixed voice data sent to devices B and C. Specifically, the mixing coefficient is determined based on the valid audio sources detected by VAD: one valid audio source results in a mixing coefficient of 1, two valid voice sources result in a mixing coefficient of 1 / 2, and three valid voice sources result in a mixing coefficient of 1 / 3. For example, suppose there is a device D (the device to be networked) that receives voice data from three other devices A, B, and C, and simultaneously captures voice data from its local microphone (MIC). The specific mixing logic is as follows: Device D collects voice data from devices A, B, and C through a voice transmission channel, and simultaneously captures voice data from its local MIC. When it needs to send voice data to device A, if the data from devices B and C and the MIC are all detected as valid, the volume of each of these three voice data is attenuated by 1 / 3 (to prevent data overflow). The processed voice data is then superimposed to generate mixed voice data, which is sent to device A through the Bluetooth voice transmission channel. If the data from devices B and C and the MIC are all detected as invalid, 0 data is sent to the other devices. The mixed voice data sent to devices B and C is processed in the same way. In addition, device D also plays the voice data from devices A, B, and C through its speaker for its own listening.

[0183] If only devices A and B are determined to be valid voice (the voice data from the MIC is invalid voice), then the audio signals from the two data sources A and B and the voice signal from the MIC are each attenuated by 1 / 2. The processed voice data are then superimposed to generate mixed voice data, which is then sent to device C via the Bluetooth data channel.

[0184] If only one of devices A, B, and MIC is determined to be valid voice, the audio signal from that data source will be sent directly to C without volume adjustment.

[0185] If all data sources are determined to be invalid speech (i.e. no one is speaking), then an empty data packet or a silence signal is sent to C to indicate that there is no valid speech content in the current time period.

[0186] The mixing logic sent to Device A and Device B uses the same mixing logic as described above, sending voice data from A, C and the local MIC to Device B, and sending voice data from B, C and the local MIC to Device A.

[0187] The present invention has been described in detail above. The specific embodiments are provided only to help understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make various improvements and modifications to the present invention without departing from its principles, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A method for implementing a Bluetooth-based multi-user self-organizing network intercom, characterized in that: Includes the following steps: The device to be networked initiates a network formation request; The device to be networked sends broadcast data packets to surrounding devices and continuously scans for surrounding devices, using either broadcast or scanning methods. Select devices in the surrounding network whose parameters meet the preset connection conditions as target networking devices; Establish a communication channel connection between the device to be networked and the target device, wherein the communication channel includes a data transmission channel and a voice transmission channel; A connection quality assessment mechanism is used to assess the connection quality of the communication channel, generate assessment results, and adjust the network connection based on the assessment results; The connection process of the communication channel includes the following steps: initiating a data transmission channel connection request to establish multiple data transmission channel connections between the device to be networked and the target device; completing the exchange of network information; initiating a voice transmission channel connection to establish multiple voice transmission channel connections between the device to be networked and the target device; The connection quality assessment mechanism includes the following steps: The system acquires the signal strength between each device in the network in real time, determines whether the signal strength between each device in the network is lower than the preset signal strength threshold, and if so, triggers the reconnection mechanism and reselects the connection path. Real-time acquisition of packet loss rate between upstream network devices and corresponding network devices of each network device; Determine whether the packet loss rate between the upstream network device and the corresponding network device of each network device in the network is greater than the preset disconnection threshold. If so, disconnect the network device from the corresponding upstream network device and trigger reconnection. Determine whether the packet loss rate between the upstream network device and the corresponding network device of each network device in the network is greater than the preset mute threshold and less than or equal to the preset disconnection threshold. If so, control the corresponding network device to perform mute processing. Determine whether the packet loss rate between the upstream network device and the corresponding network device of each network device in the network is greater than the preset relay threshold and less than or equal to the preset mute threshold. If so, control the network device to stop forwarding the data received from the corresponding upstream network device.

2. The method for implementing a Bluetooth-based multi-user self-organizing network intercom according to claim 1, characterized in that: The networking method includes serial networking. The networking information of the serial networking includes head device, intermediate device, tail device, the position of each device in the network, the number of devices in the network, and the list of device addresses in the network. There are several intermediate devices, which are located between the head device and the tail device. The information synchronization of the serial network includes the following steps: The target networking device that successfully connects to the device to be networked is the newly added device. The newly added device is then connected to the serial network group. The newly added device simultaneously sends link update requests to the preceding device and the following device until the preceding device receives the link update request. The head device initiates a network information synchronization command, which is transmitted sequentially from the head device to the tail device. After receiving the network information synchronization command, the tail device starts from the tail device. Each intermediate device before the tail device replies to the previous intermediate device and sends a response data packet. The head device receives response data packets from the intermediate and tail devices, integrates them, generates summary information, and transmits the integrated summary information to the entire serial network. After the network information transmission is completed, the head device and the tail device respectively obtain identifiers.

3. The method for implementing a Bluetooth-based multi-user self-organizing network intercom according to claim 2, characterized in that: The networking method also includes tree networking, and the networking information of the tree networking includes root node device, stem node device, leaf node device, number of devices in the network, and list of device addresses in the network. The information synchronization of the tree-shaped network includes the following steps: After a node device scans and finds the target networking device, it connects the target networking device as a new device to the tree network group and sends a link change notification to the root node device. When the root node device receives a link change notification, it initiates a network information synchronization request, which is then passed down from the root node to each node device. Each node device receives the network information synchronization request and replies with confirmation information from the root node device.

4. The method for implementing a Bluetooth-based multi-user self-organizing network intercom according to claim 3, characterized in that: Both the serial network group and the tree network group are equipped with a retransmission mechanism, which is as follows: The system determines whether the data packet sending device receives a response from the data packet receiving device within a preset response time after sending the data packet. If not, the data packet sending device will retransmit the packet.

5. The method for implementing a Bluetooth-based multi-user self-organizing network intercom according to claim 1, characterized in that: The broadcast or scan mechanism uses Bluetooth Low Energy to discover each device. The data transmission channel uses an asynchronous connectionless link to transmit network information. The voice transmission channel uses a synchronous connection-guided link, an enhanced synchronous connection-guided link, or an isochronous channel to transmit voice data in real time.

6. The method for implementing a Bluetooth-based multi-user self-organizing network intercom according to claim 1, characterized in that: It also includes processing the voice data of the voice transmission channel. The process of processing the voice data includes: The device to be networked collects voice data from the target network device that has successfully connected to it through the voice transmission channel, and simultaneously collects voice data from the local microphone of each device. The VAD algorithm and volume detection are used to detect the voice data of the target networking device that has successfully connected to the network and the corresponding local MIC voice data, and to filter out the valid voice data. The effective speech data is mixed to generate mixed effective speech data; The mixed and valid voice data is encoded and sent to the target networking device that is already connected to the device to be networked.

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