Measurement-based coverage function for green femtocell networks

In this paper, we propose a self-optimized coverage function for LTE femtocells embedded in a macrocell area. Each Femto Base Station (FBS) adapts its pilot power, and thus the coverage, to the on-site traffic demand. Under low traffic conditions the FBSs, whose presence is not essential for the proper operation of the network, reside in a low power Listen Mode. In this way a relevant energy saving on entire femtocell network can be achieved. In a high-load scenario, FBSs dynamically create high capacity zones under interference constraints. This permits to improve system capacity and offload more traffic from the nearby macrocell and, in the same time, to minimize co-channel interference in the femtocell tier.