Optimal Cache Leasing from a Mobile Network Operator to a Content Provider

TL;DR

This paper develops an optimization framework for a mobile network operator and content provider to efficiently lease cache space at the network edge, maximizing traffic offloading and hit probability with minimal costs.

Contribution

It introduces a joint optimization model for cache leasing and content placement, providing an exact solution using Benders decomposition and analyzing different association policies.

Findings

Optimal leasing and placement strategies improve traffic offloading.

Association policies significantly impact performance gains.

Maximized hit probability when MNO follows CP actions.

Abstract

Caching popular content at the wireless edge is recently proposed as a means to reduce congestion at the backbone of cellular networks. The two main actors involved are Mobile Network Operators (MNOs) and Content Providers (CPs). In this work, we consider the following arrangement: an MNO pre-installs memory on its wireless equipment (e.g. Base Stations) and invites a unique CP to use them, with monetary cost. The CP will lease memory space and place its content; the MNO will associate network users to stations. For a given association policy, the MNO may help (or not) the CP to offload traffic, depending on whether the association takes into account content placement. We formulate an optimization problem from the CP perspective, which aims at maximizing traffic offloading with minimum leasing costs. This is a joint optimization problem that can include any association policy, and can also derive the optimal one. We present a general exact solution using Benders decomposition. It iteratively updates decisions of the two actors separately and converges to the global optimum. We illustrate the optimal CP leasing/placement strategy and hit probability gains under different association policies. Performance is maximised when the MNO association follows CP actions.