Comparison Between Centralized and Distributed Databases in IP Multimedia Subsystem

The IP Multimedia Subsystem (IMS) refers to the standard for a telecommunication system that controls multimedia services accessing different networks. IMS is integrated in both 4G and 5G networks to enable packet-switched voice calls service. The design of the IMS system always needs to be completed before developing any functions of the system. Choosing of database model is an important part of designing the system, and there are some models of database implementation, such as centralized databases and distributed databases. Moreover, both centralized and distributed databases have some advantages and drawbacks. Each type of database requires different techniques to store and search the users' information. The database implementation and these techniques are described in detail in the manuscript. Besides, simulation of each database implementation is also conducted to evaluate the databases' performance. With the performance comparison between centralized and distributed databases, the IMS system can be optimized by choosing a suitable database model.