Jointly Optimal Routing and Caching with Bounded Link Capacities

TL;DR

This paper introduces a joint optimization framework for routing and caching in networks with capacity limits, formulating it as a complex submodular maximization problem and proposing an efficient heuristic algorithm with strong performance.

Contribution

It models the joint routing and caching problem with link capacity constraints as a continuous DR-submodular maximization and provides a polynomial-time heuristic with provable approximation guarantees.

Findings

The proposed algorithm achieves solutions within $1-1/e$ of the optimal.

Extensive experiments show the algorithm outperforms existing methods.

The approach effectively handles arbitrary network topologies with capacity constraints.

Abstract

We study a cache network in which intermediate nodes equipped with caches can serve requests. We model the problem of jointly optimizing caching and routing decisions with link capacity constraints over an arbitrary network topology. This problem can be formulated as a continuous diminishing-returns (DR) submodular maximization problem under multiple continuous DR-supermodular constraints, and is NP-hard. We propose a poly-time alternating primal-dual heuristic algorithm, in which primal steps produce solutions within $1-\frac{1}{e}$ approximation factor from the optimal. Through extensive experiments, we demonstrate that our proposed algorithm significantly outperforms competitors.