A Case Study on Multiparty Calls Differentiation in the IP Multimedia Subsystem

The IP Multimedia Subsystem (IMS) is a key component of 3G networks aimed at enabling the seamless provisioning of IP multimedia services to end users. Multiparty sessions (or conferences), which enable the conversational exchange of multimedia content between several parties, represent one of the specialized services supported by the IMS. Conferencing is the basis of a wide range of applications such as: debating; multiplayer gaming; and distance learning. In order to offer users a predictable experience and a controlled quality when using such applications, suitable QoS mechanisms must be supported in the IMS. We have previously proposed a two-party call differentiation scheme along with an architectural framework enabling its realization in the IMS. In this work, we apply our call differentiation scheme to the conferencing case, by studying the effects of call differentiation on the operation of the standard IMS conferencing architecture. This is achieved via a case study including the definition of a differentiated IMS conferencing architecture, the elaboration of various differentiated multiparty sessions scenarios, and the implementation of a proof-of-concept prototype.