Capacity Expansion Design On SDH Transmission Network Of China Railcom Group In BeiJing City

Nowdays the society enter into the information age, the highly developed information society requests the communication network to provide varied telecommunication service. The amount of information corresponded by communication net transmission, exchanging and handling will increase uninterrupted, which request modern correspondence net to develop with more digitized, intelligentized and personalized. The basic strokes of the transmission network are based on the SDH and the DWDM, the full title of the SDH is called synchronization digital transmission system, SDH is one kind of transmission system (agreement). Like the PDH-- the same with orbit digital transmission system, the frame structure, multiplying way, transmission speed rank, connection code pattern of the digital signal and so on are standarded in this kind of transmission system.The SDH transmission system is the important composition fraction of the communication net, the develop of communication net is directly decided by the quality of the transmission system. The information superhighway developed at present by international community, among the points is a set of the big capacity transmission network, which means that the semaphore speed is continuously raised on the transmission line, the transmission band is expanded, just like a continuously expanding which can accept a great deal of superhighway that can contain more cars flowing. In this thesis the stratify type network structure, the ring network structure and its appliance condition are introduced according to the present condition of communication network of China Railcom Group in Beijing and are analyzed via to the angle of how to organize a SDH network. To be based on reality, the develop shape of local transmission network is set out in Beijing and the suggestion and the conceives are proposed in the original optimized network. Including:the network structure of the local net; the quantity and the location exchange; the design of the network analysissitus structure; the anticipation and computing in each office and station traffic; the computing and the trunk circuit demand of the trunk circuit matrix in each station and the office; the closed path organization and the time slot allocation; the computing of the relay distance in the office; the choosing type of the equipment; the design of the network safeguard methods; the synchronously design of the network.