A Learning-Based Approach to Caching in Heterogenous Small Cell Networks

Abstract

Abstract-A heterogenous network with base stations (BSs), small base stations (SBSs) and users distributed according to independent Poisson point processes is considered. SBS nodes are assumed to possess high storage capacity and to form a distributed caching network. Popular files are stored in local caches of SBSs, so that a user can download the desired files from one of the SBSs in its vicinity. The offloading-loss is captured via a cost function that depends on the random caching strategy proposed here. The popularity profile of cached content is unknown and estimated using instantaneous demands from users within a specified time interval. An estimate of the cost function is obtained from which an optimal random caching strategy is devised. The training time to achieve an ǫ > 0 difference between the achieved and optimal costs is finite provided the user density is greater than a predefined threshold, and scales as N 2 , where N is the support of the popularity profile. A transfer learningbased approach to improve this estimate is proposed. The training time is reduced when the popularity profile is modeled using a parametric family of distributions; the delay is independent of N and scales linearly with the dimension of the distribution parameter.

Femtocaching assisted multi-source D2D content delivery in cellular networks

“…In fact, MRT and zero-forcing beam forming (ZFBF) technology in MIMO system [14,20,21] can make one FAE transmit multiple data stream to different users at the same time, and also support multi-devices in transmitting the same file to a receiver simultaneously. The complexity caching scheme for multiple access has been investigated deeply in [5,14], by which the optimum file placement strategy can be found even if a RUT can connect several FAEs and we do not carry out further discussion.…”

“…46, Jianshe East Road, 453007 Xinxiang, China Full list of author information is available at the end of the article transmit data directly. By pre-storing popular files and dispatching data via D2D, the system has a higher gain with the increase of file storage capabilities at the network edge [4,5]. The reason behind this is that the most popular files are more likely to be accessed by the majority of users, although there are huge amount of traffic suffering by the network.…”

Random caching based cooperative transmission in heterogeneous wireless networks

“…Caching at SBSs has been proposed as a promising approach for remarkably reducing backhaul load by prefetching popular files into storages at SBSs in large-scale small cell networks or HetNets [14]- [20]. In [14]- [17], the authors consider caching the most popular files at each SBS, which we in this paper refer to as "most popular caching (MPC)".…”

“…In [18], the authors consider random caching with uniform distribution at SBSs, assuming that file requests follow a uniform distribution, which we call "uniform caching (UC)". In [19] and [20], the authors consider random caching with files being stored at each SBS in an i.i.d. manner, which we refer to as "i.i.d.…”

“…The MPC scheme considered in [14]- [17] does not provide any spatial file diversity. In contrast, the caching designs in [18]- [20] can provide file diversity.…”