How does a voice jumper transmit digital and voice signals at the same time?
Publish Time: 2024-11-28
A voice jumper is a technology that transmits voice signals over the Internet. In order to transmit digital and voice signals simultaneously, the voice jumper system uses a series of complex technologies and protocols.
1. Digitized speech signal
First, voice jumper technology converts voice signals into analog electrical signals through a microphone. These analog signals are then converted into digital signals using an analog-to-digital converter (ADC). This process is called analog-to-digital conversion (A/D conversion). The advantage of a digital signal is that it is less susceptible to noise and can be easily transmitted over a network.
2. Data compression
In order to reduce bandwidth usage and transmission delay, voice signals need to be compressed before being sent. Commonly used compression algorithms include G.711, G.729, Opus, etc. These algorithms can significantly reduce data volume while maintaining voice quality.
3. Grouping and packaging
Compressed voice data is split into small packets (typically 20-30 millisecond speech segments). Each packet contains information such as voice data, timestamp, sequence number and destination address. These packets are called Real-Time Transport Protocol (RTP) packets.
4. Transport protocol
Voice jumpers use multiple protocols to ensure that voice data packets are transmitted efficiently and reliably. Major agreements include:
Real-Time Transport Protocol (RTP): Used to transport real-time data such as voice and video streams. RTP provides timestamps and sequence numbers to help the receiving end correctly reconstruct the voice signal.
Real-time Transmission Control Protocol (RTCP): Works in conjunction with RTP to provide feedback information on transmission quality and help adjust transmission parameters to ensure voice quality.
User Datagram Protocol (UDP): Voice jumpers typically use UDP as the transport layer protocol because UDP provides low latency and is suitable for real-time communications, although it does not guarantee the order or integrity of packets.
Transmission Control Protocol (TCP): TCP can also be used when packet order and integrity need to be ensured, but is typically used to transmit control information or non-real-time data.
5. Network transmission
Packaged voice data packets are transmitted over the Internet. Since network conditions may fluctuate, voice jumper systems usually use some mechanisms to deal with network delay, packet loss, and jitter (delay changes):
Jitter Buffer: At the receiving end, the jitter buffer is used to smooth out fluctuations in network delay and ensure the continuity of the voice signal.
Forward Error Correction (FEC): Adds redundant data at the sending end to help the receiving end reconstruct the lost data when a packet is lost.
Adaptive Jitter Control: Dynamically adjusts the jitter buffer size based on network conditions to balance voice quality and latency.
6. Decompression and reconstruction
After the voice jumper system at the receiving end receives the data packet, it first performs error detection and correction (if FEC is used), and then rearranges the data packet according to the timestamp and sequence number. Then, a decompression algorithm is used to restore the digital signal to the original speech signal, and a digital-to-analog converter (DAC) is used to convert the digital signal into an analog signal, which is finally played through the speaker.
7. Transmission of digital signals
During a voice jumper call, if digital data (such as phone numbers, conference control information, etc.) needs to be transmitted, these data are usually transmitted through signaling protocols (such as SIP, H.323, etc.). The signaling protocol is responsible for establishing, managing and terminating calls, and can also carry control information during the call.
Voice jumper realizes efficient transmission of voice signals on the Internet by digitizing, compressing, grouping, transmitting and reconstructing voice signals. At the same time, digital data is transmitted through signaling protocols, allowing the voice jumper system to process voice and digital signals at the same time, providing rich communication functions.
