Mobile networks are experiencing prodigious increase in data volume and user density , which exerts a great burden on mobile core networks and backhaul links. An efficient technique to lessen this problem is to use caching i.e. to bring the data closer to the users by making use of the caches of edge network nodes, such as fixed or mobile access points and even user devices. The performance of a caching depends on contents that are cached. In this paper, we examine the problem of content caching at the wireless edge(i.e. base stations) to minimize the discounted cost incurred over infinite horizon. We formulate this problem as a restless bandit problem, which is hard to solve. We begin by showing an optimal policy is of threshold type. Using these structural results, we prove the indexability of the problem, and use Whittle index policy to minimize the discounted cost.
翻译:移动网络正在经历数据量和用户密度的大幅增长,这对移动核心网络和反向通道链接造成了巨大负担。缓解这一问题的一个有效办法是使用缓存技术,即利用边端网络节点的缓存,例如固定或移动接入点,甚至用户设备,使数据更接近用户。缓存的性能取决于缓存的内容。在本文中,我们研究了无线边缘(即基地站)内容的缓存问题,以尽量减少在无限的地平线上产生的折扣成本。我们将此问题描述为难以解决的无休止的土匪问题。我们首先展示了最佳的政策是临界的。我们利用这些结构结果,证明问题的可指数性,并使用惠特尔指数政策来尽量减少折扣成本。