Research On Railway Telecommunication Network In Next Generation Network

The transition from traditional telecommunication network to Next Generation Network (NGN) is speeding up and SoftSwitch is the key technology of NGN. To improve development of railway information technology, it is necessary to use NGN technology in construction of railway telecommunication network. This thesis mainly discusses the key technologies on how to construct railway telecommunication network in NGN. It can be divided into two parts: 1) packet carrier network, 2) control and service network.First, traffic model of service network is very important in designing a new network and analyzing network performance. So, after analyzing the difference between actual network traffic and traffic model of Possion stochastic, some kinds of traffic model are considered and flow-cumulating model is used to simulate the actual network traffic. Then, it is shown through theoretical analysis and simulation results that self-similarity of network traffic seriously influence the performance of network.Second, packet carrier network provides the function of transporting all sorts of service information, which includes voice stream, data stream and video stream in NGN. So, it is important how to provide high level QoS guarantee in packet carrier network of NGN. There are a lot of technologies about QoS guarantee in IP network, RPR network and WLAN network. After research on them, some proposals are given on constructing packet carrier network of railway telecommunication network in NGN.Finally, SoftSwitch is the core equipment of call controlling in NGN. The SoftSwitch is an opening platform for value-added services and railway telecommunication services can be treated as special services in NGN. Through analysis of structure of application system in SoftSwitch network, a special application system in railway telecommunication network is proposed. And a multimedia dispatch telecommunication system using SoftSwitch technology is built as a trail system.