The Study Of Network VTS Video And Audio Transmission Based On RTP

With the rapid development of economic, the maritime traffic of our country makes a great progress in recent years. However, the rapid increase in ship traffic flow and the more complex navigation environment have put forward higher requirements to our country's maritime traffic management. Strengthen the safety management in the inshore waters, organize the navigation order, coordinate and command the search and rescue. Those are urgently problems which needed to be solved to improve coastal ship safety management. Especially in dealing with emergencies at sea, by sharing the information of VTS, the remote decision-makers can timely access to intuitive real-time voice and video images, realize face to face interactive command which has become a trend of international maritime emergency command.Designed to handle non-real time data transmission, Internet can only provide "best effort" service. However Audio/Video transmission asks for high real-time performance. TCP doesn't meet this requirement for its error detection and retransmission mechanism. If we singly adopt UDP, transmission quality will be very poor, because UDP doesn't provide any quality of service. RTP protocol is a real-time network transmission protocol of the IP internet for voice, image, fax and other multimedia data. Combining RTP/RTCP and UDP together will meet real-time requirements and assurance quality of service at the same time.Firstly, he described the information-sharing network structure; current problems and key technologies of the current network VTS, then expounded the problems in voice-video network transmission, and gave an in-depth analysis of Real-time Transport Protocol and Real-time Transport Control Protocol carrying out audio and video transmission combine with UDP. Afterwards he designed a remote audio and video transmission system, and analyzed the choice of the key modules and communication networks. Finally, made a detailed description of the establishment for communication process and the implementation of RTP Real-time Transport Protocol library, analyzed and improved the delay jitter and flow control in transmission service quality.