Service Control Architecture in IP Multimedia Based 3G Networks

The Universal Mobile Telecommunication System (UMTS) promises to deliver a plethora of advanced, innovative, and feature-rich applications to end-users in a 3G wireless environment. Within the Third Generation Partnership Project (3GPP) work has commenced on the specification of the IP Multimedia subsystem (IMS), which provides the required functionality for session control and mobility management in the core UMTS network to facilitate these services and applications. This paper addresses the Service Control Architecture for the IM subsystem in UMTS networks. More specifically, the paper discusses various configurations for the residency of service application platforms and controlling entities in the UMTS network architecture, currently under consideration by the 3GPP. Service provisioning models are discussed for services offered by the home network operator, as well as services offered by non-home sources such as the visited network or a third party Application Service Provider (ASP). The discussion will include a simplified example of service provisioning for a roaming user.