An Energy Saving Approach for Femtocell Coverage Function

In this paper, we propose a self-optimization coverage function for LTE femtocells embedded in a macrocell area. In this approach each Femtocell Base Station continuously adapts the operation mode according to the traffic conditions in order to fulfill the following objectives: improve the overall system capacity, reduce co-channel interference between adjacent femtocells, improve energy efficiency of the overall system. The proposed algorithm is distributed without any signaling overhead compared to a centralized solution. In a low load scenario our power control scheme limits the number of simultaneously activated femtocells, achieving a significant power saving on the entire femtocell network. As the number of active users increases, each Femto Base Station adapts its transmit power, and thus the coverage, as a function of the traffic demand, aiming to offload more traffic from the macrocell. This results in an improved overall system capacity and a larger energy efficiency of the overall cellular network.