Popularity-Driven Content Placement and Multi-Hop Delivery for Terrestrial-Satellite Networks

To enhance the efficient content dissemination in terrestrial-satellite networks, we investigate the joint content placement and multi-hop delivery problem to reduce the average path length for content delivery. In the considered architecture, contents can be shared in multi-hop terrestrial networks while each content is offloaded to only one terrestrial user via the satellite. Considering both content popularity and channel conditions, content placement is performed by optimizing the satellite downlink resource allocation where a distance-sensitive popularity parameter is introduced. Moreover, we formulate a path length minimization problem for content delivery in terrestrial networks, and a relay-aided multi-hop routing algorithm is proposed. Our simulation results show that the proposed scheme forcefully strikes a balance between terrestrial network backlogs and satellite downlink throughput, and achieves a better multi-hop delivery performance.