A zonebased content precaching strategy in vehicular edge networks Abstract   Content precaching is a kind of significant technology to lower response delay and improve network performance, especially for the delaysensitive services in dynamic vehicular edge networks. Therefore, in this paper, we propose a zonebased content precaching strategy, which aims to implement an active content caching through two algorithms: precaching zone selecting algorithm     P  C  Z  S     and precaching node selecting algorithm     P  C  N  S    . Firstly, we organize the edge servers (    E  S    s) with a zonebased way at the edge, and assign a     M  a  n  a  g  e  r     node to collect the information of each zone; with the help of road topology and tables information recorded in     M  a  n  a  g  e  r     nodes,     P  C  Z  S     can predict the vehicle motion and zone sojourn time with a high accuracy, and further get a content precaching zone by comparing estimated request delay and zone sojourn time; then,     P  C  N  S     checks whether the content has been cached in the     C  S  T     of the zone selected by     P  C  Z  S    , if     C  S  T     hits, the precaching process is over, otherwise, by combining     E  S     centrality, load degree with content popularity, we perform     P  C  N  S     to select a specific     E  S     node to precache 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.

Quality of ExperienceAware Mobile Edge Caching through a Vehicular Cloud Densification through small cells and caching in base stations have been proposed to deal with the increasing demand for Internet content and the related overload on the cellular infrastructure. However, these solutions are expensive to install and maintain. Instead, using vehicles acting as mobile caches might represent an interesting alternative. In our work, we assume that users can query nearby vehicles for some time, and be redirected to the cellular infrastructure when the deadline expires. Beyond reducing costs, in such an architecture, through vehicle mobility, a user sees a much larger variety of locally accessible content within only few minutes. Unlike most of the related works on delay tolerant access, we consider the impact on the user experience by assigning different retrieval deadlines per content. In our paper, we provide the following contributions: (i) we model analytically such a scenario; (ii) we formulate an optimization problem to maximize the traffic offloaded while ensuring user experience guarantees; (iii) we propose two variable deadline policies; (iv) we perform realistic tracebased simulations, and we show that, even with low technology penetration rate, more than 60% of the total traffic can be offloaded which is around 20% larger compared to existing allocation policies.