The Research And Implementation Of The 3G Access-Gateway In Distributed Service Network

With the development of Web 2.0 and mobile Internet technologies, IT trend appears gradually in the telecom network field. It means that:on the one hand, the loose coupling scheme is applied between the hardware platform and software, and the various applications are developed and run on the commodity hardware platforms; on the other hand, the demand of diversity and personality of applications is far more than the past. In addition, there are many drawbacks in the traditional centralized core network, which catch more and more attention from both academia and industry, such as single point of failures, low resource utilization and high cost of development and maintenance. Distributed Service Network (DSN) is a new architecture of telecom network which applies loose coupling scheme between the hardware platform and software and takes advantages of both Peer-to-Peer (P2P) technology and Session Initiation Protocol (SIP). DSN makes use of P2P technology to organize the homogeneous service nodes, general computing devices in the core network, to form a self-administrative P2P overlay. Therefore, the load balancing can be executed between peer nodes to relieve the excessive traffic, improve resource utilization and avoid single point of failures effectively. On the other hand, SIP is used as the universal singling protocol to manage the sessions in the core network which simplifies the network management and makes new applications easy to develop.IP Multi-media Subsystem has already been widely deployed in recent years and it has become a main technology in the field of 3G telecom network evolution. After a brief introduction and analysis of IMS and DSN, a study to evolve IMS to DSN in core network and access network will be given. In the following part, the key gateway, protocols adaptor (PA) which helps 3G network to access DSN core network will be mainly discussed. PA is located between Radio Access Network (RAN) and DSN core network and it shields against the specific core network implementation technologies for RAN. PA not only has to accomplish the protocol transformation between Radio Access Network Application Protocol (RANAP) and SIP, but also has to manage the radio resource such as radio resource allocation and release. In addition, PA is responsible for controlling the media gateway to handle with the media resources. In this paper, the detailed description of the design and implementation of PA is given. Extensive experimental results show that the PA proposed in this paper can fulfill the expected functions to help the 3G network to access DSN core network while maintaining a certain stability. At last, the future work will be focused on improving PA's performance further.