Cache-enabled small cell networks with local user interest correlation

In this paper we study cache-enabled small cell networks (SCNs) with local regularly requested content sampling to take into account local user interests for the cache decisions. We consider Zipf-like local content popularity with variables indicating the correlation level of user interests in the same region. Based on stochastic spatial models for the small cell base station (SCBS) and user distribution, we give analytical result on the cache service probability which is the probability of an arbitrary user to find its requested content cached in its nearby SCBSs. The tradeoff between the service probability and the sampling cost is discussed with the optimal sampling distance given by maximizing the service probability under the cost constraint. Numerical results are shown with different correlation levels of local user interests, which validate our analysis on the service-cost tradeoff.