A novel approach on femtocell placement in the commercial buildings using genetic algorithm

The femtocell networks have been developed to solve the indoor coverage issues. In the large commercial buildings, finding the minimum number of femtocells and their locations with a full coverage of the building is a complicated problem. This article attempts to minimize the number of femtocells in a large building while providing maximum coverage. In this article, the locations of the femtocells are determined such that the total number of handovers in the building is minimal. For this purpose, the building area is divided into small and equal-sized subregions, and a femtocell matrix coverage is obtained for each subregion using the path-loss equation. We utilize the femtocell matrix coverage and propose a mathematical model to minimize the number of femtocells with a maximum (almost complete) coverage of the building area. We employ the genetic algorithm to solve this NP-hard problem. An efficient algorithm is also presented to create the initial population for the genetic algorithm. Based on the past behavior of the users, we select the locations for the femtocells to reduce the number of handovers. Numerical results indicate that with almost complete coverage, our proposed method reduces the femtocell counts up to 55% and reduces the number of handovers up to 30% compared with the previous work.