Energy Efficient Spectrum Allocation for Green Radio in Two-Tier Cellular Networks

Recently, a new concept "Green Radio" has been focused, which means to reduce the existing energy consumption of information and communication technologies (ICTs). Cellular networks account for a rather large share of energy use, lowering their energy consumption appears beneficial, especially BS, which costs the most energy in the cell. Macro-femto network, as a new two-tier cellular network, has obvious advantages in lowering cellular energy consumption. In this paper, we firstly introduce a spatial two-tier model and two new metrics for analyzing the cellular network. Secondly, we analyze the downlink energy consumption of BSs and femtocell access points (FAPs). Thirdly, we provide a novel energy efficient spectrum allocation strategy in marco-femto cellular networks for minimal downlink energy consumption. Finally, simulation results show that this new spectrum allocation strategy can help the cellular network to be energy efficient.