Research Of Real-time Voice Communication Base On Packet Switched Network

Nowadays, the Internet has been widly used in many areas. In addition totraditional e-mail, http and other services, with the increasing popularity anddevelopment of network, streaming media technology to become a hot researchtopic in recent years, and with it following a lot of multimedia communicationservices. These business usually require a higher real-time, you also need higherbandwidth, and these data has a strong burst. But there is a big advantage that youcan use the global Inernet IP envirenment as a platform for data transmission.Thereby, we can reduce communication costs and there will be so many applicationforms.This paper mainly studies the transmission of voice data over packetswitched network, using the network to transfer real-time voice data. By theintroduction of streaming media in the first paragraph, we can say that thetraditonal transport layer protocols can not meet the requirements of thetransmission of voice, vedio and other real-time data. The transmission of text andpictures is completely different from real-time voice, a short delay willl causeseriouse quality of service. How to deliver real-time voice data effectively hasbecome the key issue of real-time vioce communication over network.The paper first introduces a new transport protocol, PRT Real-time TransportProtocol, and describes the format, composition and details of the protocol, as wellas an open source JRTPLIB library realized by C++language. Then introduces thevoice compression algorithm and proposes a new voice compression algorithm.Now, Voice Compression is a key issue in real-time transmission, using as littledata as possible to restore a good voice in order to reduce occupying the bandwidthand network congestion. Finally introduces the design and realization of the system,which also uses silence detection algorithm, and this paper proposes a new silence detection algorithm. The experiments show that only40%of the time is effectiveduring a call. So communication quality can be better improved if the datatransmission is removed during the slient state.