.3 G Application Servers, Telecommunications Applications Framework

The third generation mobile network regards Application Server as the main platform for telecommunication services with the development of Value-added services. Application Server is a program, which exposes business logic to the client, using a variety of protocols, and provides the means to access business logic for client applications. There are two main kinds of service development patterns at present, one is based on open APIs, and the other is based on scripts. Both patterns have their disadvantages so that they can not meet the need of services development. A new development pattern based on telecommunication application frameworks is proposed in this paper, which combines the advantages of the former two development patterns. A real telecommunication application framework named COJoin available for 3G application servers is also implemented.COJoin telecommunication framework is designed for telecommunication services on application servers, which supports key service logics and common tools. It adapts event-driven and component-based software architecture, and consists of four components which are container-router component, service load component, protocol component, service-related component.This kind of development pattern uses a new XML script language named XSDL (COJoin Service Developping Language) to build the structure and main part for service logic, and uses Java codes or common components in framework to implement details for service logic. COJoin also implements a state management mechanism using"tree"structure based on sessions, which can be used in every telecommunication service.Some key technologies are used in COJoin, such as event-route algorithms, the methods for online service update, and the new load balancing algorithms-DWR(Dynamic Weighted Random Algorithm). DWR algorithm uses weighted random to dispatch messages and dynamic feed back to adjust loading. Simulation results show the algorithm have good performance and simple calculation.COJoin is tested in many aspects, The result shows that COJoin can decrease the cost for service development, improve the performance, and so on.The conclusion of COJoin application framework and direction for future research is listed at the end of this paper.