The Application And Implementation Of V5.2 Interface In Next Generation Network

Along with the digitization of communication network and the massive usage of the optical fiber and digital user transmission system, Access network (AN), which is a great impetus to the development of telecommunication service, was introduced into the telecommunication world. The V5 interface is widely applied between the local exchange (LE) and AN as a kind of standard and completely open new digital interface. On one side, the LE can support many kinds of user access types including simulation access and digital access by providing V5 interface function. On the other side, because of the openness characteristic of V5 interface, the LE can communicate with any type of AN from any equipment manufacturers as long as both sides follow the same specifications of V5 interface, which is advantageous to the technology and service evolution in LE and AN separately and causes the AN market to open completely.Although the V5 interface technology has already been developed quite maturely in the traditional circuit switching network, the development and application of V5 interface will face new opportunity and challenge along with the rapid development of next generation network as well as the trend of the existing network evolving to the next generation network. The next generation network is one kind of brand-new network architecture, it uses packet switching as the core technology, takes the thought of which the bearing and the control separates, the control and the service separates, transmitting many kinds of comprehensive services including voice, data, video, multimedia etc. through packet switched network. Although the next generation network has the superiority which the traditional circuit switching network is unable to compare, but it is impossible to abandon the existing network to build a new network. Therefore, in order to protect investment and avoid wasting the existing resources, these two kinds of networks will coexist in very long period of time in the tendency of the existing network evolving to the next generation network. In the process of the next generation network substituting the traditional circuit switching network gradually, the function realization and the way of accessfor V5.2 interface will be changed in the next generation network architecture.This article's main research work is the application of V5.2 interface in next generation network as well as the design and realization of V5.2 interface in the Softswitch system. The paper first analyses the functions and characteristics of next generation network, Softswitch and media gateway, and introduces several kinds of plans for the existing network to next generation network evolution, and from this proposes two application ways of V5.2 interface in the PSTN network to the next generation network evolution process. Then according to the V5.2 interface own characteristic and the system structure characteristic of the next generation network, the paper makes a deep exploration and discussion on how to design and realize the V5.2 interface in the Softswitch system. The design work mainly includes the following several aspects: the design of general solution for V5.2 interface in NGN framework, the design of V5.2 interface in Softswitch system, the design of the three flows for V5.2 interface, including the link status reporting flow, the system initiation flow and the V5 user basically calling flow. The realization work mainly includes two parts, namely the implementation of V5 protocol stack and the implementation of interface module between V5 protocol stack and external modules. The paper finally summarizes the characteristic and innovation of this article, and gives some directions for further study and research on this subject.