Cache Aided Wireless Networks: Tradeoffs between Storage and Latency

TL;DR

This paper explores the fundamental limits of cache-aided wireless networks, introducing a new metric called normalized delivery time (NDT) to analyze the trade-offs between latency and cache storage capacity.

Contribution

It presents a new information theoretic lower bound on NDT and demonstrates its optimality for various system parameters, advancing understanding of cache-latency trade-offs.

Findings

Derived a new lower bound on NDT for cache-aided networks.

Established the optimality of the bound for several system configurations.

Provided insights into how cache capacity impacts delivery latency.

Abstract

We investigate the fundamental information theoretic limits of cache-aided wireless networks, in which edge nodes (or transmitters) are endowed with caches that can store popular content, such as multimedia files. This architecture aims to localize popular multimedia content by proactively pushing it closer to the edge of the wireless network, thereby alleviating backhaul load. An information theoretic model of such networks is presented, that includes the introduction of a new metric, namely normalized delivery time (NDT), which captures the worst case time to deliver any requested content to the users. We present new results on the trade-off between latency, measured via the NDT, and the cache storage capacity of the edge nodes. In particular, a novel information theoretic lower bound on NDT is presented for cache aided networks. The optimality of this bound is shown for several system parameters.