Research On Next Generation Network And Softswitch Technology

Nowadays, telecommunication and network technology change with each passing day. Softswitch and the next generation network(NGN) based on it are domestic and overseas highlight.This dissertation introduced the definition and characters of NGN and pointed out its architecture and key technologies. At the same time, it also illustrated the evolution of PSTN, Internet, CATV network, mobile communication network, access network, transmission network towards NGN.Then, researched Softswitch generally and systematically. Firstly, introduced background, definition and characters of Softswitch. Secondly, proposed a new architecture project based on PS(Position Server) to solve the problems of complexity of route selecting in layered architecture and data maintenance in plane architecture. This project has important referential value in the practice of Softswitch network architecture. Thirdly, introduced protocols for Softswitch, such as IP Phone Protocol, Media Gateway Protocol, Call Signaling Protocol and interlink protocol. Fouthly, discussed the QoS (Quality of Service) problem in Softswitch network and introduced InterServ and DiffServ model. Then constructed a mathematical model to analyze different packet dispersion strategy's effect on quality of VoIP (Voice over IP) and performed an emulational study. Fifthly, introduced classes, characters and service mode of services in Softswitch network.Lastly, the author anticipated the applied prospect of NGN based on Softswitch in military communication networks and proposed some main points on security and secrecy with combination of actual work in the army.