Efficient switched services over a DVB-SH/3G network

International audienceFourth generation networks result from the cooperation be- tween different existing networks, thus taking benefit from their complementary properties. In this context, recent re- searches have addressed Digital Video Broadcast (DVB) net- works, which benefit of very high broadcast capacities, but are unidirectionnal. Coupling a DVB network with a bidi- rectional network brings bidirectionality and service inter- activity. In this context, we focus on a DVB-SH (satellite services for hand-held devices) network, which is a hybrid (satel- lite/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 avail- able 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 ser- vices over DVB networks. We specified an efficient switch- ing 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 pre- diction algorithm that aims to guarantee efficient switching while maintaining service continuity