Service Discovery System In Next Generation IP Multimedia Subsystem

The rapid development of network technologies and the increase of user requirements will definitely lead to a revolution in the networks. IP Multimedia Subsystem (IMS) was proposed by 3GPP, and it was born to be a perfect platform for the novel services. IMS also facilitates the merge of existing heterogeneous networks. Nowadays, Peer-to-Peer (P2P) technology has gained its popularity in Internet. It's predictable that P2P will also play an important role in the global networks.Based on the research on IMS and P2P, we have proposed the Next Generation-IP Multimedia Subsystem (N-IMS). N-IMS inherits the structure and functional entities of the traditional IMS to the most extent, but organizes the functional entities in a P2P manner. The simulation results show the performance of N-IMS is better than that of the traditional IMS in nodes searching, network maintenance, scalability, etc. In the future, the concept of service will be enlarged. Service is not only limited to voice, video or file transfer, but also comprises all kinds of functionalities that can be used by other network elements. There will be more types of services and the number of available services will increase as well. Because of the above-mentioned reasons, an efficient service discovery system is highly needed. However, up to now, there is no service discovery related protocol defined in IMS, which is an important part of IMS.After in-depth study of IMS and existing service discovery protocols, we have proposed a novel service discovery system for N-IMS which is coined as N-IMS SD. N-IMS is a good foundation for N-IMS SD, and the N-IMS functional entities, Session Initiation Protocol (SIP) and Session Description Protocol (SDP) are adopted as parts of N-IMS SD. In N-IMS SD, there are two manners to perform service discovery: Active Service Discovery and Passive Service Discovery. User centricity is well achieved in N-IMS SD. The employment of Context-Awareness is a good feature of N-IMS SD, by which adaptability can be realized. From the simulation results, we can conclude that the performance of N-IMS SD using P2P and the layered architecture is better than that of the traditional architecture.N-IMS and N-IMS SD provide a good solution for deployment of future global networks, and we have already verified their good performance by simulations. In the future, we believe that more careful and in-depth research is worth doing on N-IMS and N-IMS SD.