Towards an innovation oriented IP multimedia subsystem [IP Multimedia Systems (IMS) Infrastructure and Services]

This article proposes an approach to IMS policy control based on session policies that achieve transparent end-to-end session establishments between IMS terminals. The article identifies drawbacks in the current IMS policy control methodology, discusses how these drawbacks may negatively influence the potential of IMS to provide innovative services, and describes how the new approach overcomes these drawbacks. Our proposal offers modularity and scalability properties that enable operators to establish policies and modify existing ones without major changes in the IMS core. Thus, policies can be applied transparently to SIP dialogs between terminals and modified on the fly without tearing down ongoing dialogs. The article also discusses a test bed implementation that worked as a proof-of-concept