One-node-based mobile architecture for a better QoS control
Résumé
Although IMS (IP Multimedia Subsystem) brings a large set of new services and offers service convergence, it introduces complexity on network architecture and procedures. This paper raises the problems encountered during IMS session establishment procedure for the situation when only partial radio resources are available in the access network for supporting the requested service. It also highlights the long delay introduced by this procedure especially for a high number of IMS users. To solve these issues, we propose a new architecture, called UFA (Ultra Flat Architecture). UFA is a distributed and flat IMS architecture composed of only Base stations that combine control and user plane functions. We define session establishment procedure for UFA and specify the way it handles access network radio resource information to adapt the service accordingly. We compare UFA and IMS classical architecture in terms of session establishment delay for normal and overloaded cases. Evaluation uses queuing theory and shows that UFA enables a considerable gain