Backhaul-Based Cooperative Caching in Small Cell Network
As mobile devices become more and more ubiquitous, mobile traffic demands are increasing exponentially. To deal with such challenge, caching is considered as an effective way to reduce redundant transmissions. Cooperative caching allows the cache storage to be used more efficiently and increases cache hit rate to further reduce the downloading latency. Recent researches assume that a mobile user can be served by multiple small cell base stations (SBSs) simultaneously, yet this hypothesis requires costly re-design of the infrastructure’s physical layer. In this paper, we propose a backhaul-based cooperative caching scheme which groups several SBSs into a cluster and the SBSs cooperate through wired interfaces. We first formulate a delay minimization problem for cooperative caching, and then propose a greedy algorithm to obtain the content placement with maximum reduced delay. We also explore the impact on end-to-end latency under different simulation parameters, such as cache size and the skewness of the popularity of requested contents.
This work was financially supported by the Center for Open Intelligent Connectivity from The Featured Areas Research Center Program within the framework of the Higher Education Sprout Project by the Ministry of Education (MOE) in Taiwan. Tsai’s work was supported in part by the Ministry of Science and Technology (MOST) under Grant 106-2221-E-006-007- and Grant MOST 107-2221-E-006-062-, and Industrial Technology Research Institute (ITRI).
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