Liu Jing
Railway is the main artery of China's economy, the backbone of the national transportation system and an indispensable part. It has the characteristics of highly centralized management and close links in work. Railway transportation includes a series of working nodes. If something goes wrong at one point, it will affect the safety and smoothness of the whole line. Failure to eliminate the danger in time and control the development of the situation will cause a wider range of congestion and paralysis, which can be described as a close call. Therefore, ensuring smooth flow is the most basic requirement of railway transportation, and safe production is the eternal theme of railway transportation. Railway emergency communication transmission system is produced to meet this demand. How to use the scene environment to quickly restore and establish the emergency communication channel at the scene of the incident, to ensure that the on-site audio-visual materials are transmitted back to the command center in the first time, to provide support for rescue decision-making, and to receive rescue instructions in time, so as to win time for eliminating accidents, reducing losses and restoring the line to traffic as soon as possible, it is necessary to study and design a multi-means, multi-channel and multi-service emergency communication transmission scheme, which can be connected and connected under any circumstances. Firstly, the paper describes the current business status and development process of railway emergency communication network and emergency communication system, then analyzes their existing problems and requirements, puts forward a layered and sliced railway emergency communication system architecture model, and describes the link layer, IP switching layer, coding transmission layer and business control layer in detail. Secondly, three different physical link access technologies, wired, wireless and satellite, are compared, and the rescue site and road section are completed. Then, the video coding technology in IP network environment is discussed in depth, and the popular H.264 algorithm is analyzed and implemented in Linux environment. At the same time, aiming at the coding transmission scheme, the design idea and implementation of streaming transmission using application layer RTP/RTCP protocol are put forward, and the solutions to the problems involved in network adaptation, code stream automatic control, network state feedback and so on are given. Finally, the problem of data storage after receiving is analyzed, different storage methods are compared, and a storage scheme suitable for this design is given. The research work of this paper mainly provides some ideas for the research and development of railway emergency communication, which has certain practical application value. In addition, it can provide accurate and timely information for railway emergency rescue work and play an important role in decision support and emergency rescue plan formulation. …