Online algorithms for content caching: an economic perspective

Content Caching at intermediate nodes, such that future requests can be served without going back to the origin of the content, is an effective way to optimize the operations of computer networks. Therefore, content caching reduces the delivery delay and improves the users’ Quality of Experience (QoE). The current literature either proposes offline algorithms that have complete knowledge of the request profile a priori, or proposes heuristics without provable performance. In this dissertation, online algorithms are presented for content caching in three different network settings: the current Internet Network, collaborative multi-cell coordinated network, and future Content Centric Networks (CCN). Due to the difficulty of obtaining a prior knowledge of contents’ popularities in real scenarios, an algorithm has to make a decision whether to cache a content or not when a request for the content is made, and without the knowledge of any future requests. The performance of the online algorithms is measured through a competitive ratio analysis, comparing the performance of the online algorithm to that of an omniscient optimal offline algorithm. Through theoretical analyses, it is shown that the proposed online algorithms achieve either the optimal or close to the optimal competitive ratio. Moreover, the algorithms have low complexity and can be implemented in a distributed way. The theoretical analyses are complemented with simulation-based experiments, and it is shown that the online algorithms have better performance compared to the state of the art caching schemes

A Survey on Caching in Distributed Small Cell Networks

The exponential growth of mobile devices such as smartphones and tablets, coupled with proliferation of online social networks has considerably increased the traffic in cellular networks. In contrast to classical cellular traffic that was only based on voice and audio communications, the recent technologies have resulted in bandwidth-intensive services such as video streaming, and video conferencing increases the traffic among users. This traffic surge affects the capacity of existing wireless networks which makes it difficult to ensure the high quality-of-service (QoS) required by the cellular services. In order to handle with the limited capacity of existing cellular networks and keep up with the strict QoS requirements, in terms of data rate and delay tolerable application-specific delays, a new generation of wireless networks has emerged. To achieve the requirements of this new generation and provide efficient infrastructure support for this data deluge, several research challenges must be addressed and solved. In this paper a survey on literature about small cell networks in distributed environment is presented which focus on caching aspect to improve the performance. The related work for caching in distributed small cell networks is also presented