Delivery-Secrecy Tradeoff for Cache-Enabled Stochastic Networks: Content Placement Optimization

TL;DR

This paper develops an analytical framework for optimizing content placement in cache-enabled cellular networks, balancing file delivery efficiency and secrecy levels through probabilistic strategies.

Contribution

It introduces a novel physical-layer security based content placement optimization considering different secrecy requirements in stochastic networks.

Findings

Closed-form expressions for hit and secrecy probabilities derived.

Optimal probabilistic content placement policy formulated.

Numerical results confirm the importance of secrecy levels in balancing tradeoff.

Abstract

Wireless caching has been widely recognized as a promising technique for efficient content delivery. In this paper, by taking different file secrecy levels into consideration, physical-layer security oriented content placement is optimized in a stochastic cache-enabled cellular network. We propose an analytical framework to investigate the nontrivial file delivery-secrecy tradeoff. Specifically, we first derive the closed-form expressions for the file hit and secrecy probabilities. The global optimal probabilistic content placement policy is then analytically derived in terms of hit probability maximization under file secrecy constraints. Numerical results are demonstrated to verify our analytical findings and show that the targeted file secrecy levels are crucial in balancing the file delivery-secrecy tradeoff.