A load-conscious cell selection scheme for femto-assisted cellular networks

To improve benefits of macrocell offloading in femto-assisted cellular networks, concept of cell biasing has been proposed. Cell biasing attempts to offload users from macrocell by modifying cell selection criteria. This is done by adding a positive bias to the measured signal from femtocells before performing cell selection. While the macrocell offloaded users may experience lower signal quality from femtocells, they are benefited by receiving higher bandwidth. From users´ point of view, it is desirable that user equipments receive highest possible bitrate from the target base station. However, cell biasing only considers received signal strength to make cell selection decisions. The bitrate received at a user equipment is directly proportional to available bandwidth and user load at target base station. In this paper, we propose an enhanced cell selection scheme that considers scheduling opportunities available at femtocell by analyzing the current load and femtocell specific constraints such as maximum user count and minimum signal strength. Obtained results show that our work provides the best performance in terms of both system throughput and energy efficiency among all compared cell selection schemes.