A framework for mobile data offloading to leased cache-endowed small cell networks

Cache-endowed small cell networks constitute a timely and effective solution for mobile network operators (MNOs) who strive to serve the massive content demand of the mobile users. However, the deployment of small cell base stations (SBSs) requires significant economic investments, while site acquisition issues render it infeasible in several cases. Yet, one potentially explosive factor for network expansion remains unexploited, namely, an increasing number of residential users install in their premises privately-owned SBSs (femtocell or WiFi access points) in order to serve their own needs. In this work, we envision an MNO offering incentives to the SBS owners to cache and deliver content items requested by the nearby mobile users. We model the interaction between the MNO and the SBS owners as a Stackelberg game, and show that the incentive design problem requires to know the content caching policy, which in turn should be jointly derived with the request routing policy. We then introduce a framework for the joint derivation of incentive, caching and routing policies. Numerical results indicate that our mechanism provides a substantial potential for reducing the MNO's costs, depending on the willingness of the SBS owners to lease their resources and the spatio temporal characteristics of the mobile data demand. © 2014 IEEE