Capacity offloading in two-tier small cell networks over unlicensed band: A hierarchical learning framework

In this paper, we investigate the capacity offloading over unlicensed band for two-tier dual-mode small cell networks. We formulate this problem as a Stackelberg game. Specifically, the macro base station (MBS) is modeled as leader and small base stations (SBSs) are followers. MBS adopts a traffic flow pricing mechanism and broadcasts the price information to all SBSs firstly, then each SBS allocates the traffic load in licensed and unlicensed band via appropriate power allocation in the sequel, considering the traffic flow payment charged by MBS in licensed band. Then, we propose two hierarchical learning schemes based on Q-learning algorithm. Simulation results show the effectiveness of the proposed schemes.