Caching with time-varying popularity profiles

B. N. Bharath, K. G. Nagananda, D. Gündúz, H. V. Poor

Research output: Chapter in Book/Report/Conference proceedingChapter


This chapter considers the problem of content caching at the small-cell base stations (sBSs) in a heterogeneous wireless network. A cost function called the “offloading loss, " which measures the fraction of the requested files that are not available in the sBS caches, is used as a metric for evaluating the performance of the proposed caching scheme. In contrast to the previous approaches that consider time-invariant and perfectly known popularity profiles, caching with non-stationary and statistically dependent popularity profiles (assumed unknown, and hence, estimated) is studied from a learning-theoretic perspective. A high probability bound on the offloading loss difference referred to as a probably approximately correct (PAC) result is derived. Here, the offloading loss difference refers to the error between the estimated and the optimal offloading loss. The difference is shown to be a function of the Rademacher complexity, the β-mixing coefficient, the number of time slots, and a measure of discrepancy between the estimated and true popularity profiles. Using insights from this bound, a practical cache update algorithm is proposed. Simulation results are presented to show its superiority over periodic updates. This chapter also presents caching performance analyses for Bernoulli and Poisson request models.

Original languageEnglish (US)
Title of host publicationEdge Caching for Mobile Networks
PublisherInstitution of Engineering and Technology
Number of pages18
ISBN (Electronic)9781839531224
ISBN (Print)9781839531231
StatePublished - Jan 1 2022

All Science Journal Classification (ASJC) codes

  • General Engineering


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