The IP Multimedia Subsystem in Next Generation Networks

The IP multimedia Subsystem (IMS) is a network functional architecture that is seen as a promising so- lution for facilitating multimedia service creation and deployment, as well as supporting interoperability and network convergence. IMS allows network operators to play a central role in traffic distribution, therefore being more than "bit pipes". For all these reasons, IMS has generated intense research and standardization efforts. The aim of this paper is to present the overall IMS ar- chitecture and protocols, as well as the related stakes.