Efficient Switched Services over a DVB-SH/3G Network

Abstract

Fourth generation networks result from the cooperation between different existing networks, thus taking benefit from their complementary properties. In this context, recent researches have addressed Digital Video Broadcast (DVB) networks, which benefit of very high broadcast capacities, but are unidirectionnal. Coupling a DVB network with a bidirectional network brings bidirectionality and service interactivity. In this context, we focus on a DVB-SH (satellite services for hand-held devices) network, which is a hybrid (satellite/terrestrial) standard. We couple DVB-SH with a 3G cellular network, thus providing bidirectionality. DVB-SH benefits from a very high bandwidth capacity that allows unidirectional IP-TV channels broadcast. A residual bandwidth in the DVB-SH path may still be available because of the variable bit rates of served flows. In a previous study [1], we focused on this small residual bandwidth and its potential utilization. Our idea was to use this architecture in order to provide interactive low cost services over DVB networks. We specified an efficient switching of IP services, coming from 3G networks, to the residual bandwidth of DVB networks. In this paper, we extend DVB residual bandwidth thanks to some DVB channels reserved by the 3G provider and study the impact of this extension on the type and the quality of targeted services. This paper particularly highlights the scheduling algorithm of the 3G flows switched over DVB residual bandwidth. It also presents a user subscription prediction algorithm that aims to guarantee efficient switching while maintaining service continuity.