However, users of satellite communications need expensive and cumbersome equipment to receive and transmit satellite signals. Furthermore, as the amount of information being broadcast increases, average user latency increases as well. In many situations, users in a locality may have similar interests and hence they can be better served by a local broadcast schedule. A two stage satellite-terrestrial wireless broadcast system can provide more efficient service. In such a system, main server broadcasts information via satellite to the geographically distributed local ground stations.
Every station has limited buffer capacity to store the items broadcast by the satellite.
According to their cache content, and the interests of their users, local stations deliver the information to their users via terrestrial wireless channel. We develop novel methods for the joint cache management and scheduling problem encountered in these systems. Our results demonstrate that two stage systems can provide more efficient data delivery compared to the single stage systems.