Integrated Sensing, Communication, and Caching for Content Delivery in SAGIVNs

The space-air-ground integrated vehicular networks (SAGIVNs) can efficiently accelerate the deployment of the Internet of Vehicles (IoV) and enrich the content distribution methods in the networks. In this paper, we propose a content delivery scheme in SAGIVNs that integrates sensing, communication, and caching. Specifically, we first perceive the content requests of the vehicles through which the vehicles covered by the same roadside unit (RU) can be facilitated to request the contents collaboratively. Then, based on the location and path of each vehicle, the perceived request information can be transmitted between different RUs, enabling efficient collaborative content recommendation between the RUs. After that, by jointly considering the contents recommended by different RUs, the popularity of each content, and the limited cache resources, the content caching model of each RU is formulated as a knapsack problem, where a dynamic programming method is designed to obtain the optimal caching strategy. Compared with the conventional schemes, the simulation results show that the proposed scheme can lead to the highest hit ratio and the lowest transmission delay.