Next generation networks will result from 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, which benefit of very high broadcast capacities, and has tried to couple them with complementary networks. In our work, we focus on DVB-SH, satellite services for hand-held devices, which is a hybrid (satellite/terrestrial) standard. We couple DVB-SH with a 3G cellular 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 two reasons; the variable bit rates of served flows and/or some DVB reserved channels by the 3G provider. In our work, we focus on this small residual bandwidth and its potential utilization. The idea is to realize an efficient switching of IP data, coming from 3G networks, to the residual bandwidth of DVB Networks. The goal is to use this architecture in order to provide interactive low cost services over DVB networks. Keyword: Network convergence, DVB, 3G, residual bandwidth, switching, multimedia, low cost services