A method and system for transmitting voice data with voice band

Abstract

This invention provides a method and system for transmitting voice data. The method includes: receiving a voice data signal transmitted by a client front-end device via an Internet Protocol link, wherein the client front-end device is communicatively connected to a first terminal device, and the voice data signal is a voice data signal transmitted by the first terminal device to a second terminal device; transmitting the voice data signal to a public switched telephone network server via a local area network gateway, wherein the public switched telephone network server transmits the voice data signal to a third terminal device.

Description

Technical Field

[0001] This invention relates to the field of information processing technology, and in particular to a method and system for transmitting voice data. Background Technology

[0002] With the evolution of communication technologies, the traditional Public Switched Telephone Network (PSTN) is being replaced globally by next-generation networks based on IP protocols (such as NGN and IMS). IP networks employ packet switching technology, offering advantages such as low cost and high flexibility. By using Real-Time Transport Protocol (RTP) combined with forward error correction (FEC) and packet loss concealment (PLC) technologies, they can effectively compensate for inherent network latency, jitter, and packet loss issues, thereby achieving efficient communication with acceptable subjective listening quality.

[0003] However, existing IP communication technologies face significant challenges when handling Voice-Band Data (VBD) services. VBD refers to machine-to-machine (M2M) data communication transmitted over the voice band of traditional telephone lines. Typical applications include fire alarm panels, fax machines, and modem communication used in low-speed data acquisition (SCADA) systems in industrial control. These systems rely on the high stability, low latency, and synchronous clock characteristics of the PSTN network. When attempting to carry these services over asynchronous IP networks, problems such as high latency and poor data transmission quality arise. A highly reliable, low-latency end-to-end transmission method for VBD data over IP networks is needed to truly achieve a seamless replacement of the PSTN network. Summary of the Invention

[0004] This invention provides a method and system for transmitting voice data with voice over IP, which solves the problem of unstable transmission links when transmitting voice data with voice over IP networks.

[0005] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:

[0006] This invention provides a method for transmitting voice data via voiceband, applied to a Session Border Controller (SBC), the method comprising:

[0007] The client front-end device receives voice data signals transmitted via Internet Protocol link. The client front-end device is communicatively connected to the first terminal device. The voice data signals are voice data signals transmitted from the first terminal device to the second terminal device.

[0008] The voice data signal is sent to the public switched telephone network server through the local area network gateway, and the public switched telephone network server sends the voice data signal to the third terminal device.

[0009] Optionally, the receiver receives voice data signals transmitted by the client front-end device via an Internet Protocol link, including:

[0010] The system receives a first voice data signal with voice overlay sent by a first client front-end device through a first Internet Protocol link. The first client front-end device is communicatively connected to a third terminal device. The first voice data signal with voice overlay is a voice data signal with voice overlay sent by the first terminal device to the third terminal device.

[0011] Optionally, transmitting the voice data signal via a local area network gateway to a public switched telephone network server includes:

[0012] The first voice data signal is sent to the public switched telephone network server through the local area network gateway, and the public switched telephone network server sends the first voice data signal to the third terminal device.

[0013] Optionally, the method further includes:

[0014] The system receives a second voice data signal transmitted via a second Internet Protocol link from a second client front-end device among at least two client front-end devices. The second client front-end device is communicatively connected to a second terminal device. The second voice data signal is a voice data signal transmitted from the second terminal device to a third terminal device.

[0015] Optionally, transmitting the voice data signal via a local area network gateway to a public switched telephone network server includes:

[0016] The second voice data signal is sent to the public switched telephone network server through the local area network gateway, and the public switched telephone network server sends the second voice data signal to the third terminal device.

[0017] Optionally, the method further includes:

[0018] The received first or second voice data signal is sent to the unified cloud platform via a third Internet Protocol link; wherein the unified cloud platform forwards the first or second voice data signal to the public switched telephone network server, and the public switched telephone network server sends the first voice data signal to the third terminal device.

[0019] Optionally, the method further includes:

[0020] When packet loss occurs on the first Internet Protocol link, the system receives the first voice data signal automatically retransmitted by the first client-side front-end device; or...

[0021] When packet loss occurs in the second Internet Protocol link, the second voice data signal is automatically retransmitted by the second client front-end device.

[0022] Optionally, the method further includes:

[0023] When the first Internet Protocol link fails, the first voice data signal automatically retransmitted by the first client's front-end device is received through the redundant backup link of the first Internet Protocol link; or,

[0024] When the second Internet Protocol link fails, the second voice data signal automatically retransmitted by the second client front-end device is received through the redundant backup link of the second Internet Protocol link.

[0025] This invention also provides a voice data transmission system, comprising:

[0026] The Session Boundary Controller (SBC) is used to receive voice data signals transmitted by a client front-end device via an Internet Protocol link. The client front-end device is communicatively connected to a first terminal device, and the voice data signals are voice data signals transmitted by the first terminal device to a second terminal device.

[0027] The voice data signal is sent to the public switched telephone network server through the local area network gateway, and the public switched telephone network server sends the voice data signal to the third terminal device.

[0028] Optionally, the Session Border Controller (SBC) is also used to send the received voice data signal to the unified cloud platform via a third Internet Protocol (IP) link; the unified cloud platform forwards the voice data signal to the Public Switched Telephone Network (PSTN) server, wherein the PSTN server sends the voice data signal to the third terminal device.

[0029] The technical solution of the present invention has at least the following effects:

[0030] The above-described solution of the present invention receives voice data signals transmitted by a client front-end device via an Internet Protocol link. The client front-end device is communicatively connected to a first terminal device, and the voice data signals are voice data signals transmitted from the first terminal device to a second terminal device. The voice data signals are then transmitted to a public switched telephone network server via a local area network gateway. The public switched telephone network server then transmits the voice data signals to a third terminal device, thereby achieving reliable transmission of voice data over an IP network. Attached Figure Description

[0031] Figure 1 This is a flowchart illustrating the method for transmitting voice data according to an embodiment of the present invention;

[0032] Figure 2 This is a schematic diagram of the architecture of a voice data transmission system provided in an embodiment of the present invention. Detailed Implementation

[0033] Exemplary embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this invention will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0034] like Figure 1 As shown, an embodiment of the present invention proposes a method for transmitting voice data in the voice band, applied to a session boundary controller (SBC), the method comprising:

[0035] Step 11: Receive the voice data signal sent by the client front-end device through the Internet Protocol link. The client front-end device is communicatively connected to the first terminal device. The voice data signal is the voice data signal sent by the first terminal device to the second terminal device.

[0036] Step 12: The voice data signal is sent to the public switched telephone network server through the local area network gateway, wherein the public switched telephone network server sends the voice data signal to the third terminal device.

[0037] In step 11 of this embodiment, firstly, the SBC listens for and receives IP data streams from one or more CPE devices through its network interface. These data streams carry voice data signals transmitted over the Internet, such as alarm signals from a fire alarm panel, fax signals from a fax machine, or modem data from a SCADA system. Due to the Internet link between the CPE and the SBC ( Figure 1The links 1 and 2 in the signal may experience packet loss, jitter, and delay. The CPE has processed the original VBD signal before transmission. Specifically, it uses standard TCP when the packet loss rate is low and UDP-based QUIC or SPRT protocols when the network conditions are poor. It also uses a multi-path transmission method, using multiple physical links simultaneously or as backups for transmission.

[0038] When receiving data, the SBC needs to perform the following operations:

[0039] (1) Multi-link data aggregation and sorting: If the CPE enables multi-link transmission, the SBC needs to aggregate data packets from different IP paths and reorder potentially out-of-order data packets according to the embedded sequence number to restore the original data stream.

[0040] (2) Reliable Transmission Protocol Processing: As the receiver of the reliable transmission protocol, the SBC needs to acknowledge the received data packets and initiate retransmission requests for lost data packets. This process ensures that the VBD data finally submitted to the subsequent processing modules is complete and in the correct order.

[0041] (3) Signal parsing and service identification: After obtaining the complete data stream, the SBC will parse the signal and identify the type of service it carries; for example, by analyzing signal characteristics, it can distinguish whether it is ALARM, FAX, or MODEM communication. At the same time, the SBC may also obtain the destination information of the call from the signaling. At this point, the SBC has received and processed a complete and reliable VBD digital signal and is ready to make routing decisions.

[0042] In step 12, after successfully receiving and identifying the service type as a VBD service sensitive to latency and packet loss, the SBC activates its intelligent routing function. The SBC makes routing decisions according to a preset strategy; the core of this strategy is: for VBD services such as ALARM / FAX / MODEM, the path with the shortest latency and highest reliability is prioritized. The SBC will determine whether to use the UC platform ( Figure 1 Forwarding via link 3 in the network can introduce uncontrollable latency due to the long path and complex processing, thus increasing the risk of communication failure. Therefore, the intelligent routing decision engine generates instructions to route the VBD signal to the local PSTN landing interface (…). Figure 1 Link 4 in the middle). The specific process includes:

[0043] (1) Protocol and signal format conversion: The SBC converts the VBD digital signal carried inside into a format compatible with the E1 gateway device connected locally, including extracting the payload from the IP data packet and encapsulating it into a TDM (Time Division Multiplexing) frame structure that can be recognized by the E1 trunk line.

[0044] (2) Transmission to PSTN via local area network: The SBC sends the converted TDM signal stream to the directly connected E1 gateway through its local area network interface. Since the SBC and E1 gateway are usually deployed in the same computer room or data center, the transmission delay between the devices is negligible due to the LAN connection. The E1 gateway then sends the signal to the PSTN network, and the PSTN network ultimately routes the voice data signal to the destination terminal device (i.e., the third terminal device).

[0045] This invention proposes the above-mentioned technical solution, which achieves highly reliable and low-latency transmission of VBD services such as alarms, fax, and modem over IP networks by adopting a multi-link transmission mechanism and a low-latency reliable connection protocol between the client CPE and the cloud SBC, and by utilizing the intelligent routing technology of the SBC to realize the direct landing of services to the PSTN network.

[0046] In an optional embodiment of the present invention, the above method may include:

[0047] Step 21: Receive a first voice data signal with voice overlay sent by the first client front-end device through a first Internet Protocol link among at least two client front-end devices. The first client front-end device is communicatively connected to the third terminal device. The first voice data signal with voice overlay is a voice data signal with voice overlay sent by the first terminal device to the third terminal device.

[0048] Step 22: The first voice data signal is sent to the public switched telephone network server through the local area network gateway, wherein the public switched telephone network server sends the first voice data signal to the third terminal device.

[0049] In step 21 of this embodiment, the SBC, acting as a central node, typically establishes and maintains communication connections with multiple CPEs distributed across various locations simultaneously. The SBC receives data packets from the first client front-end device (CPE) on its network interface. The first CPE is a specific instance among many connected CPEs, communicating with the SBC through a specific physical or logical channel, namely a first Internet Protocol link (such as broadband or 4G / 5G wireless links at the customer's location). This first CPE is connected to a third terminal device (such as a fire alarm panel or fax machine). The CPE's role is to digitize the raw analog VBD signals (such as alarm signals or fax handshake tones) generated by the terminal device and encapsulate them into IP data packets. Therefore, the first voice data signal received by the SBC essentially originates from the first terminal device (i.e., the remote device initiating the communication) and is intended to ultimately be delivered to the third terminal device as digitized VBD service data. Since this data is transmitted over the public Internet, which is subject to packet loss, the SBC needs to process these data packets as a receiver of reliable transmission protocols. Therefore, the SBC needs to confirm the receipt of data packets, request retransmission of lost packets, and reorder the data packets according to the sequence number, thereby logically reconstructing a complete and error-free VBD data stream.

[0050] In step 22, after fully receiving the first voice data signal, the SBC parses the signal and identifies its service type (e.g., ALARM, FAX, or MODEM). For this type of M2M (machine-to-machine) communication, which is extremely sensitive to latency and jitter, the SBC determines that it should not be forwarded to the UC platform, which might introduce additional processing latency. Therefore, the SBC's intelligent routing engine generates instructions to select an optimal path, namely, directly landing on the PSTN network through the local area network gateway. This path (e.g., ...) Figure 1 Link 4 in the middle is characterized by the SBC and E1 gateway being directly connected through the local area network, with extremely close physical distance and negligible transmission delay, thus creating a network environment similar to the native PSTN for VBD services.

[0051] The SBC performs necessary protocol and format conversions on the internally processed digitized VBD signal, encapsulating it into a data format compatible with the local E1 gateway (such as a TDM frame). The SBC then sends the converted signal to the directly connected E1 gateway (i.e., the local area network gateway) via its local area network interface.

[0052] After receiving the signal from the SBC, the E1 gateway is responsible for sending it into the Public Switched Telephone Network (PSTN). The PSTN network then processes the first call, just like a regular telephone call, using its inherent synchronous and low-latency characteristics to route and deliver the voice data signal to the third terminal device, thus completing the end-to-end communication.

[0053] In an optional embodiment of the present invention, the above method may include:

[0054] Step 31: Receive a second voice data signal sent by the second client front-end device through a second Internet Protocol link. The second client front-end device is communicatively connected to the second terminal device. The second voice data signal is a voice data signal sent by the second terminal device to the third terminal device.

[0055] Step 32: The second voice data signal is sent to the public switched telephone network server through the local area network gateway, wherein the public switched telephone network server sends the second voice data signal to the third terminal device.

[0056] In step 31 of this embodiment, the SBC needs to manage connections with at least two client front-end devices simultaneously. In this step, the data source is specifically a second client front-end device (CPE), distinct from the first client front-end device, indicating that the SBC has the ability to handle multiple independent signal sources. This second CPE establishes a connection with the SBC through its dedicated second Internet Protocol link (such as a physical broadband line or mobile network different from the first CPE). This means that the overall system reliability depends not only on the multiple links of a single CPE but also benefits from the redundancy provided by multiple CPE accesses. The second voice data signal originates from a second terminal device (such as a fax machine or data acquisition device at another location) and is intended to be sent to a third terminal device (such as a centralized receiving center). Similar to processing the first CPE signal, the SBC also performs reliable transmission protocol processing on the signal from the second CPE. That is, the SBC processes multiple independent reliable data streams in parallel, performing packet acknowledgment, out-of-order reordering, and packet loss retransmission on each stream to ensure that the second voice data signal received from the second client front-end device is also complete and accurate.

[0057] In step 32, after receiving the complete voice data signal of the second call, the SBC will perform the same service type identification (e.g., determine if it is a FAX or MODEM). Regardless of which CPE the signal originates from (first or second), the SBC follows a unified core routing strategy: for VBD services, it prioritizes the path with the lowest latency and highest reliability. Therefore, the SBC will again make a decision to avoid sending this signal to the UC platform, and instead choose to directly terminate it on the PSTN network through the local area network gateway.

[0058] The SBC can route multiple VBD data streams (such as first and second voice data signals) from different CPEs and links in parallel and independently to the same local PSTN egress resource (i.e., the local area network gateway). The SBC performs protocol conversion on the processed second voice data signal, encapsulates it into a format suitable for the E1 gateway, and sends it to the gateway via the local area network. Subsequently, the Public Switched Telephone Network (PSTN) server delivers the signal to the designated third-party terminal device, thus completing this end-to-end communication.

[0059] In an optional embodiment of the present invention, the above method may include:

[0060] Step 41: The received first voice data signal or second voice data signal is sent to the unified cloud platform via a third Internet Protocol link; wherein, the unified cloud platform forwards the first voice data signal or second voice data signal to the public switched telephone network server, and the public switched telephone network server sends the first voice data signal to the third terminal device.

[0061] In step 41 of this embodiment, the following situation occurs:

[0062] (1) The E1 gateway (i.e., the direct PSTN landing interface) connected to the local area network is malfunctioning, offline, or has exhausted its resources;

[0063] (2) For some non-critical or latency-insensitive VBD services, the administrator may have configured a UC path that is cheaper or easier to manage.

[0064] (3) The destination of the call (third terminal device) may be a special number or network that can only be accessed through the UC platform;

[0065] After receiving the first or second voice data signal, the SBC will evaluate the above conditions. If it determines that the conditions do not meet the rules for direct connection to the PSTN, it will initiate the procedure.

[0066] Once the decision takes effect, SBC will transmit the reconstructed, complete VBD digital signal via a third-party internet protocol link (such as...). Figure 1 Link 3) in the process is sent to the unified cloud platform (UC Platform). In this process, SBC acts as a forwarding node. Although the VBD signal is reliably protected between CPE and SBC, the IP network from SBC to UC Platform is still subject to the latency and jitter inherent in the public network.

[0067] After receiving the VBD signal from the SBC, the unified cloud platform treats it as a regular VoIP media stream or performs secondary processing according to its own capabilities. Subsequently, the UC platform takes on the responsibility of "landing" the call to the PSTN, forwarding the signal through its own network interface to the connected public switched telephone network server (i.e., the PSTN gateway), and finally, the PSTN network delivers the signal to the third-party terminal device to complete the communication.

[0068] In an optional embodiment of the present invention, the above method may include:

[0069] Step 51: When packet loss occurs on the first Internet Protocol link, receive the first voice data signal automatically retransmitted by the first client front-end device; or,

[0070] When packet loss occurs in the second Internet Protocol link, the second voice data signal is automatically retransmitted by the second client front-end device.

[0071] In this embodiment, after establishing a data transmission channel with the CPE (whether it's the first or second CPE), the SBC continuously monitors the received data packets, including assigning a unique sequence number to each data packet. When the SBC detects that the sequence numbers of the data packets are discontinuous, or fails to receive a data packet with the expected sequence number within a certain time, it determines that a packet loss event has occurred. According to the rules of the transmission protocol used, the SBC will proactively notify the sending CPE of the packet loss event. This is achieved by sending a "negative acknowledgment" message or repeatedly acknowledging the expected packet sequence number. For example, in a TCP-like protocol, the SBC will send a duplicate ACK containing the lost packet sequence number; in a selective retransmission protocol, the SBC will explicitly request the retransmission of specific lost data packets. Upon receiving the retransmission request from the SBC, the corresponding CPE (the first or second client front-end device) will immediately retrieve a copy of the original data packet from its transmission buffer and resend it to the SBC via its internet link. After receiving the retransmitted data packet, the SBC will accurately place it in the missing position in the data stream due to packet loss, thereby reconstructing a complete, continuous, and error-free VBD data stream.

[0072] In an optional embodiment of the present invention, the above method may include:

[0073] Step 61: When the first Internet Protocol link fails, receive the first voice data signal automatically retransmitted by the first client front-end device through the redundant backup link of the first Internet Protocol link; or,

[0074] When the second Internet Protocol link fails, the second voice data signal automatically retransmitted by the second client front-end device is received through the redundant backup link of the second Internet Protocol link.

[0075] In this embodiment, the SBC and CPE detect the health status of the link through a heartbeat mechanism or continuous data stream monitoring. When the first or second Internet Protocol (IP) link completely fails (e.g., a physical line interruption or network failure causing unreachable routing), the SBC will be unable to receive any data packets or signaling through that link for a short period, thus determining that the link is in an interrupted state. On the CPE side, its multi-link module, upon detecting the failure of the primary link, immediately initiates a failover process, automatically and seamlessly switching all currently transmitting and subsequent VBD data streams (i.e., the first call with voice data signal or the second call with voice data signal) to a pre-configured redundant backup link. This backup link is another Internet connection physically isolated from the failed link.

[0076] After the switchover is complete, the CPE will resend data to the SBC through this new, normal backup link. The SBC's multipath processing module can recognize that this is a continuation of the same VBD communication session on another path, accepts and begins processing the data stream from this new link. At the same time, the SBC can correctly splice the new data packets from the backup link with the previously received data, thus ensuring the continuity of the entire VBD communication session. Users or terminal devices will not be aware of the underlying link failure.

[0077] A specific embodiment of the method for transmitting voice data in the speech band, applied to a Session Boundary Controller (SBC) provided by this invention, is as follows:

[0078] System components include:

[0079] (1) Client-side front-end equipment (CPE A): Deployed on the client side to connect to VBD terminal equipment (such as fire alarm panels);

[0080] (2) Session Border Controller (SBC): Deployed in the cloud or network core as an intelligent routing and processing center;

[0081] (3) E1 gateway: directly connected to SBC via local area network, providing an interface to PSTN network;

[0082] (4) Unified Cloud Platform (UC): A backup communication processing platform;

[0083] (5) PSTN network: a traditional public telephone exchange network;

[0084] (6) Terminal equipment: including terminals that initiate communication (such as sensor centers) and terminals that receive communication (such as alarm receiving centers).

[0085] The detailed steps of the method include:

[0086] Step S101: VBD signal acquisition and initial encapsulation;

[0087] CPE A receives an analog alarm signal from the fire alarm panel (first terminal device) it is connected to. CPE A digitizes this analog signal (e.g., using PCM encoding) to generate an initial digital voice data signal. CPE A is Add a service type identifier (such as Type=ALARM) to form the data unit to be transmitted. .

[0088] Step S102: Reliable protocol encapsulation and multi-link preparation;

[0089] CPE A is incorrect. Instead of using traditional RTP / UDP encapsulation, it is fed into a reliable transport protocol stack. This is based on current network quality measurements (such as real-time packet loss rate). ):

[0090] like Below the threshold (e.g., 2%), then the TCP protocol should be used for encapsulation;

[0091] like Above the threshold Therefore, the QUIC protocol, which is implemented on top of UDP and has stronger resistance to packet loss, is selected for encapsulation.

[0092] After encapsulation, the data packet format is as follows:

[0093] ;

[0094] Where Seq is the sequence number; For checksum verification. Meanwhile, CPE A prepares to send data via its multiple internet links (such as the primary broadband link and backup 4G links). .

[0095] Step S103: Data transmission and link monitoring;

[0096] CPE A preferentially transmits data packets via the primary Internet Protocol link (first Internet Protocol link). Send to SBC. CPE A and SBC simultaneously and continuously monitor link quality.

[0097] Step S104: SBC reception and reliability processing;

[0098] The SBC receives data packets from CPE A via the first Internet Protocol link. The SBC checks the sequence number (Seq) and checksum of the data packets.

[0099] Case A (Normal Reception): If the data packets are continuous and complete, the SBC will receive the data payload. Extract it and store it in the reconstruction buffer.

[0100] Scenario B (Packet Loss Detected): If the SBC detects a discontinuous sequence number (e.g., expected sequence number N, but received N+1), it determines that packet loss has occurred on the first Internet Protocol link. The SBC immediately sends a Negative Acknowledgment (NACK) request for the lost data packet to CPE A.

[0101] Step S105: Packet loss retransmission processing;

[0102] After receiving a NACK request from the SBC, CPE A retrieves a copy of the original data packet from its transmit buffer and immediately retransmits the packet via the currently available link (primary or backup link). Upon receiving this retransmission packet, the SBC fills the gap in the reconstruction buffer, ensuring the integrity and order of the data stream.

[0103] Step S106: Intelligent routing decision;

[0104] When SBC successfully reconstructs a complete and correctly ordered system After the data stream is received, its intelligent routing module is triggered. The routing module executes the following judgment logic:

[0105] (1) Read business type: from The parsing process reveals Type=ALARM.

[0106] (2) Evaluation of routing strategy: According to the preset rules, ALARM service is a critical service that is extremely sensitive to latency.

[0107] (3) Selecting the optimal path: For ALARM services, the path with the least latency should be selected first. Since the SBC and E1 gateway are directly connected via the LAN, the path latency is... Much lower than the path latency through the UC platform .

[0108] (4) Generate instruction: Send the ALARM data stream directly to the PSTN through the local area network gateway.

[0109] If the intelligent routing engine detects a local E1 gateway failure or resource unavailability, it will automatically activate the backup routing policy: the SBC will rebuild the route. The data stream is forwarded via a third Internet Protocol link (i.e., the link to the unified cloud platform UC). After receiving the data, the UC platform then sends the signal to the third terminal device via its own PSTN gateway. This path serves as a degradation solution to ensure uninterrupted service. Although latency may increase, reliable transmission between the CPE and SBC still guarantees data integrity.

[0110] Step S107: Protocol conversion and PSTN deployment;

[0111] SBC will reconstruct the digital VBD signal The protocol is converted from IP packet format to TDM frame format compatible with the local E1 gateway. The SBC then transmits the converted TDM signal stream to the directly connected E1 gateway via its local area network interface. The E1 gateway then sends the signal into the PSTN network.

[0112] Step S108: Final delivery;

[0113] The PSTN network routes the received VBD signal (i.e. the original fire alarm signal) according to the destination address of the call and finally delivers it to the target alarm receiving center (third terminal equipment), thus completing this highly reliable, low-latency end-to-end transmission.

[0114] The present invention proposes the above technical solution, which achieves the following technical effects by integrating multi-link transmission, reliable connection and intelligent routing technologies:

[0115] (1) Improved the communication success rate of VBD services on IP networks, avoided single point of failure through multi-link backup, and ensured service continuity;

[0116] (2) Adopt a low-latency reliable transmission mechanism to reduce the impact of packet loss and latency on M2M communication, so that the ALARM / FAX / MODEM service experience is close to the PSTN level;

[0117] (3) Connect directly to the PSTN via SBC smart routing to minimize end-to-end latency.

[0118] like Figure 2 As shown, this embodiment of the invention also provides a voice data transmission system, including:

[0119] The Session Boundary Controller (SBC) is used to receive voice data signals transmitted by a client front-end device via an Internet Protocol link. The client front-end device is communicatively connected to a first terminal device, and the voice data signals are voice data signals transmitted by the first terminal device to a second terminal device.

[0120] The voice data signal is sent to the public switched telephone network server through the local area network gateway, and the public switched telephone network server sends the voice data signal to the third terminal device.

[0121] In this embodiment, the voice data transmission system mainly includes a session boundary controller (SBC) and a client front-end device (CPE), and its system components include:

[0122] (1) Client Pre-Equipment (CPE): Deployed on the client side, it communicates with the first terminal device (such as a fax machine, alarm panel, or low-speed data acquisition device). The CPE is responsible for converting the voice data signal generated by the first terminal device into a format suitable for transmission over an IP network and sending it to the SBC via the Internet Protocol link.

[0123] (2) Session Border Controller (SBC): Running in the cloud, it acts as a bridge between the IP network and the PSTN network. The SBC receives voice data signals from the CPE and is responsible for further processing and forwarding these signals to the target network.

[0124] The transmission process of voice data signals includes:

[0125] (1) Transmission from CPE to SBC: The CPE and SBC communicate via an Internet Protocol link (e.g., Figure 2 The system establishes a connection between Link 1 and Link 2 in the network. To ensure reliable transmission, the system employs a multi-path transmission mechanism. This means that two or more parallel or backup links are established between the CPE and SBC. When one link fails, the others automatically take over, ensuring uninterrupted communication. Considering the sensitivity of voice data to packet loss, the system abandons the traditional UDP-based RTP protocol and instead uses reliable communication technologies such as TCP (when packet loss is low) or reliable link technologies built on top of UDP (such as SPRT or QUIC, suitable for "weak network" environments with poor network conditions).

[0126] (2) SBC Processing and Forwarding: After receiving the voice data signal from the CPE, the SBC will perform intelligent routing based on the signal type and the current network conditions. Specifically, it adopts two methods: The first method is that the SBC sends the voice data signal to the MSP customer's own UC Platform (such as...) via the Internet. Figure 2Link 3 in the middle), but this method may increase the risk of transmission failure due to increased communication latency; another better method is for the SBC to use its supported intelligent routing technology and local (direct connection to SBC) PSTN landing interface to directly send the voice data signal to the Public Switched Telephone Network (PSTN) server (such as the local LAN gateway) through the local LAN gateway. Figure 2 (Link 4 in the middle). This method can minimize the "landing" latency from UC to the PSTN network, ensuring the transmission quality of voice data signals.

[0127] (3) Transmission from PSTN to third-party terminal equipment: After receiving the voice data signal from the SBC, the Public Switched Telephone Network (PSTN) server forwards it to the third-party terminal equipment (such as another fax machine receiving faxes or a monitoring center receiving alarm signals). This process is based entirely on the traditional transmission method of the PSTN network, ensuring the accurate reception and processing of the voice data signal at the final end.

[0128] The voice data transmission system proposed in the above embodiments of the present invention ensures high communication reliability through a multi-link transmission mechanism, so that even a single link failure will not affect the operation of the service; and adopts reliable communication technologies (such as TCP, SPRT or QUIC) and intelligent routing to effectively reduce transmission latency and ensure the real-time performance and integrity of voice data; at the same time, the system does not depend on a specific protocol and can flexibly select according to network conditions, demonstrating good compatibility and adaptability.

[0129] In an optional embodiment of the present invention, the Session Border Controller (SBC) is further configured to send the received voice data signal to a unified cloud platform via a third Internet Protocol (IP) link; the unified cloud platform forwards the voice data signal to a Public Switched Telephone Network (PSTN) server, wherein the PSTN server sends the voice data signal to a third terminal device.

[0130] In this embodiment, the Session Border Controller (SBC), as the core processing unit, is responsible for relaying and routing voice data signals. When the SBC receives voice data signals from the Client Premises Equipment (CPE), it makes intelligent decisions based on network conditions and service type. One possible path is for the SBC to send the signal to the Unified Cloud Platform (UC Platform) via a third-party Internet Protocol (IP) link.

[0131] After receiving the signal, the unified cloud platform performs necessary protocol conversion or data processing, and then forwards the signal to the Public Switched Telephone Network (PSTN) server. Finally, the PSTN server accurately transmits the voice data signal to a third-party terminal device, such as another fax machine or a monitoring center, completing the entire transmission process.

[0132] The above are preferred embodiments of the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for transmitting voice data, characterized in that, Applied to a Session Border Controller (SBC), the method includes: The system receives voice data signals transmitted by a client front-end device via an Internet Protocol link. The client front-end device is communicatively connected to a first terminal device. The voice data signals are voice data signals transmitted from the first terminal device to the second terminal device. The client front-end device selects a protocol for encapsulation based on the current network quality measurement results. When the network packet loss rate is lower than a first threshold, the TCP protocol is used for encapsulation. When the network packet loss rate is higher than the first threshold, the QUIC or SPRT protocol based on UDP is used for encapsulation. The voice data signal is sent to the public switched telephone network server through the local area network gateway, and the public switched telephone network server sends the voice data signal to the third terminal device. The receiver of voice data signals transmitted by the client front-end device via the Internet Protocol link includes: Receive a first voice data signal with voice overlay sent by the first client front-end device through a first Internet Protocol link among at least two client front-end devices. The first client front-end device is communicatively connected to a third terminal device. The first voice data signal with voice overlay is a voice data signal with voice overlay sent by the first terminal device to the third terminal device. The method for transmitting voice data in the voice band further includes: Receive a second voice data signal with voice overlay sent by the second client front-end device through a second Internet Protocol link. The second client front-end device is communicatively connected to a second terminal device. The second voice data signal with voice overlay is a voice data signal with voice overlay sent by the second terminal device to a third terminal device. When packet loss occurs on the first Internet Protocol link, the system receives the first voice data signal automatically retransmitted by the first client-side front-end device; or... When packet loss occurs in the second Internet Protocol link, the second voice data signal is automatically retransmitted by the second client front-end device; When the first Internet Protocol link fails, the first voice data signal automatically retransmitted by the first client's front-end device is received through the redundant backup link of the first Internet Protocol link; or, When the second Internet Protocol link fails, the second voice data signal automatically retransmitted by the second client front-end device is received through the redundant backup link of the second Internet Protocol link.

2. The method for transmitting voice data according to claim 1, characterized in that, Sending the voice data signal to the public switched telephone network server via a local area network gateway includes: The first voice data signal is sent to the public switched telephone network server through the local area network gateway, and the public switched telephone network server sends the first voice data signal to the third terminal device.

3. The method for transmitting voice data according to claim 1, characterized in that, Sending the voice data signal to the public switched telephone network server via a local area network gateway includes: The second voice data signal is sent to the public switched telephone network server through the local area network gateway, and the public switched telephone network server sends the second voice data signal to the third terminal device.

4. The method for transmitting voice data according to claim 1, characterized in that, Also includes: The received first or second voice data signal is sent to the unified cloud platform via a third Internet Protocol link; wherein the unified cloud platform forwards the first or second voice data signal to the public switched telephone network server, and the public switched telephone network server sends the first voice data signal to the third terminal device.

5. A voice data transmission system, characterized in that, include: The Session Border Controller (SBC) is used to receive voice data signals transmitted by a client front-end device via an Internet Protocol (IP) link. The client front-end device is communicatively connected to a first terminal device, and the voice data signals are voice data signals transmitted from the first terminal device to a second terminal device. The client front-end device selects a protocol for encapsulation based on current network quality measurement results. When the network packet loss rate is below a first threshold, TCP protocol is used for encapsulation; when the network packet loss rate is above the first threshold, QUIC or SPRT protocols based on UDP are used for encapsulation. The voice data signal is sent to the public switched telephone network server through the local area network gateway, and the public switched telephone network server sends the voice data signal to the third terminal device. The receiver of voice data signals transmitted by the client front-end device via the Internet Protocol link includes: Receive a first voice data signal with voice overlay sent by the first client front-end device through a first Internet Protocol link among at least two client front-end devices. The first client front-end device is communicatively connected to a third terminal device. The first voice data signal with voice overlay is a voice data signal with voice overlay sent by the first terminal device to the third terminal device. The method for transmitting voice data in the voice band further includes: Receive a second voice data signal with voice overlay sent by the second client front-end device through a second Internet Protocol link. The second client front-end device is communicatively connected to a second terminal device. The second voice data signal with voice overlay is a voice data signal with voice overlay sent by the second terminal device to a third terminal device. When packet loss occurs on the first Internet Protocol link, the system receives the first voice data signal automatically retransmitted by the first client-side front-end device; or... When packet loss occurs in the second Internet Protocol link, the second voice data signal is automatically retransmitted by the second client front-end device; When the first Internet Protocol link fails, the first voice data signal automatically retransmitted by the first client's front-end device is received through the redundant backup link of the first Internet Protocol link; or, When the second Internet Protocol link fails, the second voice data signal automatically retransmitted by the second client front-end device is received through the redundant backup link of the second Internet Protocol link.

6. The voice data transmission system according to claim 5, characterized in that, The Session Border Controller (SBC) is also used to send the received voice data signal to the unified cloud platform via a third Internet Protocol (IP) link; the unified cloud platform forwards the voice data signal to the Public Switched Telephone Network (PSTN) server, wherein the PSTN server sends the voice data signal to the third terminal device.

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