ABSTRACTRecently, smaller cells such as femtocells have been proposed to address the cellular coverage problem and provide a ‘greener’ solution to future high‐speed wireless access. On the other hand, interference is a serious problem that could impact the wide deployment of femtocells. The contributions of this paper are threefold. First, we focus on the trade‐off between energy efficiency and system performance. With realistic long‐term evolution system parameters, we have shown that femtocells can indeed improve energy efficiency of the network. However, this comes with a price—performance degradation due to interference, which is especially severe in densely deployed scenarios. Second, we propose a proactive approach to handover and access management in femtocell systems, focusing especially on the interference issue of closed subscriber group femtocells. Third, we propose an efficient data offloading mechanism for interference mitigation and mobility management, with the aim to avoid potential interference and save radio resources and signalling load in the network. Simulation results have been presented to demonstrate the benefits of the proposed schemes. Copyright © 2011 John Wiley & Sons, Ltd.