Joint and Competitive Caching Designs in Large-Scale Multi-Tier Wireless Multicasting Networks

TL;DR

This paper proposes joint and competitive caching strategies in large-scale multi-tier wireless multicasting networks, deriving optimal and equilibrium solutions to enhance content delivery efficiency.

Contribution

It introduces a novel stochastic geometry-based framework for joint and competitive caching design in multi-tier wireless networks, including algorithms with convergence guarantees.

Findings

Proposed caching schemes outperform existing methods in simulations.

Derived explicit success probability expressions for various network regimes.

Established the existence and uniqueness of Nash equilibrium in competitive caching.

Abstract

Caching and multicasting are two promising methods to support massive content delivery in multi-tier wireless networks. In this paper, we consider a random caching and multicasting scheme with caching distributions in the two tiers as design parameters, to achieve efficient content dissemination in a two-tier large-scale cache-enabled wireless multicasting network. First, we derive tractable expressions for the successful transmission probabilities in the general region as well as the high SNR and high user density region, respectively, utilizing tools from stochastic geometry. Then, for the case of a single operator for the two tiers, we formulate the optimal joint caching design problem to maximize the successful transmission probability in the asymptotic region, which is nonconvex in general. By using the block successive approximate optimization technique, we develop an iterative algorithm, which is shown to converge to a stationary point. Next, for the case of two different operators, one for each tier, we formulate the competitive caching design game where each tier maximizes its successful transmission probability in the asymptotic region. We show that the game has a unique Nash equilibrium (NE) and develop an iterative algorithm, which is shown to converge to the NE under a mild condition. Finally, by numerical simulations, we show that the proposed designs achieve significant gains over existing schemes.