Effects of femtocell deployment on interference to macrocell users in a cellular network

The infrastructure of cellular network has evolved over several decades and has penetrated even the remotest part of the earth. However, as bandwidth used for next generation cellular network keeps moving to higher frequency spectrum, weaker signals for indoor cellular users has attracted additional attention. Femtocell technology has become an emerging solution and has recently been extensively studied for indoor cellular signal coverage. But, it is important to categorically analyze pros and cons of incorporating new techniques in order to judge their compatibility with existing wireless networks. The existing cellular network primarily comprises of two elements; macro base stations (M-BSs) and macro user equipments (M-UEs). In this paper, we study the effect of large scale femtocell deployment on M - UEs. Femtocells devices are designed to be deployed by individual end user, thus distribution pattern of femtocell network is not controllable. However, due to the fact that cellular signal strength decreases as the distance to the M - BS increases, it is envisioned that more femtocell devices would be installed at the edge of macrocell than the center area. Before formation of large scale femtocell, it is meaningful to simulate this deployment scenario and discover the impacts on M-UEs. We utilize a Reverse Gaussian distribution to simulate the deployment of femtocells. Then, we provide a mathematical formulation of the interference caused by femtocells on M-UEs. Extensive simulations are also performed to indicate that the results of our mathematical analysis provide an excellent guideline for interference management in future large scale femtocell deployment.