Base-Station Sleep Management in Open-Access Femtocell Networks

In this paper, we focus on enhancing the energy efficiency in open-access femtocell networks where many femto base stations (BSs) are deployed in a large public area such as airports, shopping malls, etc. In those areas, the femtocells are overlapped and underutilized during most of the operation time because femto BSs are densely deployed to support the peak traffic load. Therefore, if we properly coordinate the user association (UA) with BSs and put the femto BSs having no associated users to sleep, the energy consumption can be saved remarkably. In this paper, we propose a scheme that jointly decides the operation modes (e.g., active or sleep) of femto BSs and the association between users and the active BSs to minimize the energy consumption in the network. Simulation results show that the proposed scheme can significantly reduce the total energy consumption in the open-access femtocell networks.