Fourth generation networks are the result of the convergence of the different existing technologies, taking benefit from their complementary properties. In this context, recent research has addressed Digital Video Broadcast (DVB) networks, and has tried to couple them with complementary networks. In our work, we couple DVB-SH with a 3G network, thus providing a bidirectional interactivity path. 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 our work, we focus on this residual bandwidth. We realize an efficient switching of some 3G popular services, to the residual bandwidth of DVB Networks. The goal is to provide interactive low cost services over DVB networks. In this paper, we propose a new algorithm to efficiently schedule our 3G switched services over DVB residual bandwidth