论文标题
两层网络上的集中式层次编码缓存方案
Centralized Hierarchical Coded Caching Scheme over Two-Layer Networks
论文作者
论文摘要
本文考虑了一个层次的缓存系统，服务器与多个镜像站点连接，每个镜像与一组不同的用户连接，并且镜像站点和用户都配备了缓存的记忆。尽管已经存在研究此设置并提出了减少传输负载的编码缓存方案的工作，但仍有两个主要问题要解决：1）第一个啤酒花未编码的位置下的最佳通信负载（由$ r_1 $表示）仍然未知。 2）以前的计划基于Maddah-Ali和Niesen的数据放置和交付，这需要高的子包装水平。如何实现层次缓存系统的传输负载和子包装水平之间的良好权衡尚不清楚。在本文中，我们旨在解决这两个问题。我们首先提出了一个名为“层次放置交付阵列（HPDA）”的新组合结构，该结构表征了任何分层缓存系统的数据放置和交付。然后，我们构建了两个类别的HPDA，其中一类导致某些情况下达到最佳$ R_1 $的方案，而第二类需要较小的子包装水平，费用为略有增加的传输负载。
This paper considers a hierarchical caching system where a server connects with multiple mirror sites, each connecting with a distinct set of users, and both the mirror sites and users are equipped with caching memories. Although there already exist works studying this setup and proposing coded caching scheme to reduce transmission loads, two main problems are remained to address: 1) the optimal communication load under the uncoded placement for the first hop, denoted by $R_1$, is still unknown. 2) the previous schemes are based on Maddah-Ali and Niesen's data placement and delivery, which requires high subpacketization level. How to achieve the well tradeoff between transmission loads and subpacketization level for the hierarchical caching system is unclear. In this paper, we aim to address these two problems. We first propose a new combination structure named hierarchical placement delivery array (HPDA), which characterizes the data placement and delivery for any hierarchical caching system. Then we construct two classes of HPDAs, where the first class leads to a scheme achieving the optimal $R_1$ for some cases, and the second class requires a smaller subpacketization level at the cost of slightly increasing transmission loads.
