Green 5G Heterogeneous Networks Through Dynamic Small Cell Operation
Traditional macrocell networks are experiencing an upsurge of data traffic, and small cells are deployed to help offload the traffic from macrocells. Given the massive deployment of small cells in a macrocell, the aggregate power consumption of small cells (though being low individually) can be larger than that of the macrocell. Compared to the macrocell base station (MBS) whose power consumption increases significantly with its traffic load, the power consumption of a small cell base station (SBS) is relatively flat and independent of its load. To reduce the total power consumption of the heterogeneous networks (HetNets) we dynamically change the operating states (on and off) of the SBSs, while keeping the MBS on to avoid any service failure outside active small cells. First, we consider that the wireless users are uniformly distributed in the network, and propose an optimal location based operation scheme by gradually turning off the SBSs closer to the MBS. We then extend the operation problem to a more general case where users are nonuniformly distributed in the network. Although this problem is NP hard, we propose a joint location and user density based operation scheme to achieve near optimum (with less than 1% performance loss in our simulations) in polynomial time.
IEEE Journal on Selected Areas in Communications