A zone-based content pre-caching strategy in vehicular edge networks

Content pre-caching is a kind of significant technology to lower response delay and improve network performance, especially for the delay-sensitive services in dynamic vehicular edge networks. Therefore, in this paper, we propose a zone-based content pre-caching strategy, which aims to implement an active content caching through two algorithms: pre-caching zone selecting algorithm- PCZS and pre-caching node selecting algorithm- PCNS. Firstly, we organize the edge servers (ESs) with a zone-based way at the edge, and assign a Manager node to collect the information of each zone; with the help of road topology and tables information recorded in Manager nodes, PCZS can predict the vehicle motion and zone sojourn time with a high accuracy, and further get a content pre-caching zone by comparing estimated request delay and zone sojourn time; then, PCNS checks whether the content has been cached in the CST of the zone selected by PCZS, if CST hits, the pre-caching process is over, otherwise, by combining ES centrality, load degree with content popularity, we perform PCNS to select a specific ES node to pre-cache the content; simulation results show that our strategy has a higher prediction accuracy and dynamic adaptability, it also outperforms in terms of average response delay and cache hit ratio.