A femtocell is a radio equipment hich aims to improve the quality of the telecommunications network in customers' homes and / or in places that do not support the coverage of macro network. We focused our work on the issue of saving the energy consumed by femto-cells. In this paper, we introduce an energy efficient solution, to the cited issue, based on the removal of unwanted mobility events by classifying them according to their probabilistic importance in the context of BWA (Broadband Wireless Access) networks. We derived the analytical model of the solution. The first simulation results seem to confirm the advantage of our solution in reducing energy consumption.