Design And Implementation Of IMS & VPMN Converged Centrex As Platform

Traditional telecom network has many shortcomings. It can only provide limited services and it is difficult to upgrade. The high cost of maintenance and closed environment restrict service providers to provide competitive services to customer. After decades of IP technology development, more and more people realize that NGN (Next Generation Network) must be based on IP technology and can provide triple play of Voice/Data/Video. IMS has been defined as the core network to support all types of IP access network. The system can provide fixed and mobile convergence in all level and will solve the problems in network evolution and convergence.This thesis introduces the concept of IMS system and services and mainly describes the design and implementation of IMS application platform. Firstly it introduced the evolution and standardization progress of IMS architecture and application server. Then it provided a converged solution to meet the requirement of IMS Centrex AS specification and current tradition telecom network architecture. The converged solution not only provides seamlessly upgrading from 2G/3G, but also has many advantages in long time evolution. The main topic of this thesis is convergence of IMS Centrex AS and traditional virtual private mobile network (VPMN). The main research tasks include: 1. the detail requirement of converged Centrex AS function requirement and corresponding solution; 2. discuss the signaling process of several scenarios; 3. the detail design of network, hardware and software. In the last part this thesis introduce the following research plan。...