2021/09/01 by Shadab Mahboob, Mahboob, Shadab, Koushik Kar +3
Computer Science · Engineering · #Caching and Content Delivery #Cooperative Communication and Network Coding #Advanced Wireless Network Optimization
paper · pdf · doi:10.48550/arxiv.2109.00369
We consider the problem of video caching across a set of 5G small-cell base\nstations (SBS) connected to each other over a high-capacity short-delay\nback-haul link, and linked to a remote server over a long-delay connection.\nEven though the problem of minimizing the overall video delivery delay is\nNP-hard, the Collaborative Caching Algorithm (CCA) that we present can\nefficiently compute a solution close to the optimal, where the degree of\nsub-optimality depends on the worst case video-to-cache size ratio. The\nalgorithm is naturally amenable to distributed implementation that requires\nzero explicit coordination between the SBSs, and runs in O(N + K \log K)\ntime, where N is the number of SBSs (caches) and K the maximum number of\nvideos. We extend CCA to an online setting where the video popularities are not\nknown a priori but are estimated over time through a limited amount of periodic\ninformation sharing between SBSs. We demonstrate that our algorithm closely\napproaches the optimal integral caching solution as the cache size increases.\nMoreover, via simulations carried out on real video access traces, we show that\nour algorithm effectively uses the SBS caches to reduce the video delivery\ndelay and conserve the remote server's bandwidth, and that it outperforms two\nother reference caching methods adapted to our system setting.\n