Energy-Efficient Base Station Deployment in Heterogeneous Networks

In this letter, we address the base station (BS) deployment problem in heterogeneous networks (HetNets) and propose an energy-efficient solution. Supporting the network with additional BSs increases the total capacity of the network. However, this process may reduce the energy efficiency of the network. The proposed algorithm studies the energy efficiency aspect of the micro BS deployment problem. The deployment problem can be divided into two subproblems: choosing candidate locations for micro BSs and selecting the optimum set among these candidates. Inhomogeneous distribution of the candidate locations is misleading for different user sets. Selecting the optimum micro BSs among the candidate locations is a combinatorial problem. To provide an approximate solution to this problem, we propose a greedy algorithm. Our simulation results demonstrate that by optimizing the BS location and the number of BSs to be deployed, the energy efficiency of the system with only macro BSs can be improved up to 1.4-1.65 times for a range of realistic micro BS transmit power levels.