  In this paper, an incentive proactive cache mechanism in cache-enabled small
cell networks (SCNs) is proposed, in order to motivate the content providers
(CPs) to participate in the caching procedure. A network composed of a single
mobile network operator (MNO) and multiple CPs is considered. The MNO aims to
define the price it charges the CPs to maximize its revenue while the CPs
compete to determine the number of files they cache at the MNO's small base
stations (SBSs) to improve the quality of service (QoS) of their users. This
problem is formulated as a Stackelberg game where a single MNO is considered as
the leader and the multiple CPs willing to cache files are the followers. The
followers game is modeled as a non-cooperative game and both the existence and
uniqueness of a Nash equilibrium (NE) are proved. The closed-form expression of
the NE which corresponds to the amount of storage each CP requests from the MNO
is derived. An optimization problem is formulated at the MNO side to determine
the optimal price that the MNO should charge the CPs. Simulation results show
that at the equilibrium, the MNO and CPs can all achieve a utility that is up
to 50% higher than the cases in which the prices and storage quantities are
requested arbitrarily.
