Femtocell: Opportunities and challenges of the home cellular base station for the 3G

As indoor use of mobile phones is growing, there is increasing interest in a reliable solution to enhance indoor communications which often suffer from high signal attenuation leading to unacceptable call quality. The appearance of the dual-mode handset which supports cellular technology e.g. GSM, when the user is located outdoor and wireless technology e.g. WiFi, when the user is indoors, brings significant improvement. Moreover it allows indoor free calls by using internet software designed for phone calls, also referred to Voice over IP. This captivating technique constitutes a serious threat for cellular operators who are slowly loosing part of their profits. Recently, a possible solution, already imagined more than ten years ago, emerged. It consists in deploying a mini personal base station in each home called femtocell. The femtocell will be plugged to the fixed broadband connection already available in most households. Thus when someone enters their house, they would be able to make phone calls directly through their own femtocell instead of the overlaying macrocell. It results in a significantly improved signal quality and substantial cost savings. In this paper, we first introduce the background history that led to this new concept and then describe the femtocell technology in the context of 3G-based cellular networks. Then we present the remaining challenges and discuss the possible solutions. Finally we deal with the opportunities for users and operators and present further works.