— This paper studies the optimization techniques for scheduling multimedia packets in satellite digital multimedia broadcasting system, namely SDMB, in the presence of a return link via terrestrial mobile networks. We propose a novel approach, called proportional channel-aware packet scheduling (PCPS) scheme, to prioritize and allocate radio resources in response to the end-to-end behaviors, queuing dynamics and channel variations associated with each user in the broadcast/multicast group. In comparison with existing channel-independent scheduling schemes, simulation results prove that the proposed scheme can significantly reduce the round trip delay (RTD), improve the throughput and achieve better fairness, whilst enjoying low computational complexity, high flexibility and good scalability features. Keywords — Packet scheduling; radio resource management; multimedia broadcasting; channel-aware; SDMB.