Session Control Cooperating Core and Overlay Networks for "Minimum Core" Architecture

The authors are advocating the "Minimum Core" architecture toward New Generation Network (NWGN). In the architecture, network functionalities in the core network (e.g. mobility management, session control and application servers) are minimized by shifting them to access networks. This approach ensures high scalability essential for future networks. This paper proposes a session control method for the "Minimum Core", in which the call-setup time is guaranteed by cooperating core and overlay networks while minimizing processing and traffic load on the core network. In this method, latency on the overlay network is estimated prior to the session being established. If the estimated latency is desirable, the overlay network is utilized and otherwise the core system. This paper also proposes a blacklist scheme, which realizes on-the-fly decisions of the latency without increasing measurement traffic on the overlay network. Evaluation results on a developed test-bed system show the proposed methods drastically suppress the probability of call-setup time exceeding the desired time, and also mitigate the processing burden of the core compared to current centralized architecture.