VCC service: Standardization of integration between CS domain and IMS

This paper shows an innovative proposal of integration between circuit switched (CS) domain and IP multimedia subsystem (IMS) in the ambit of voice call continuity (VCC) service. VCC is a fundamental piece of IMS architecture proposed by 3GPP (3rd generation partnership project) specifications. This service offers continuity of a call when a mobile user moves from a domain to another, e.g. from circuit switching access network to IP access network. Mobility is a fundamental characteristic of convergent and heterogeneous networks, like IMS architecture, which is an implementation of next generation networks (NGN). 3GPP specifications do not mention anything about the protocol and the methods used to integrate the functional entities of VCC service that are distributed through CS domain and IMS. Then, this paper propose could be used for standardization of this integration, suggesting a method and a protocol for it.