Performance Evaluation of Energy Efficiency with Sleep Mode in Ultra Dense Networks

The Ultra Dense Network (UDN), as one of key techniques in 5G, is expected to support massive connections and offload the intense volume of data traffic. Nonetheless, the small cell BS density raises the issue of energy efficiency, especially when data transmission is not frequent in a certain time or location. One effective approach to reduce energy consumption is to leverage the BS sleep mode, which disables energy hungry functions and components. In this paper we examine existing energy efficiency schemes, and introduce schemes in the context of UDN. Furthermore, we implement and compare various representative schemes in the UDN scenario via simulation. Through extensive experimentation, we demonstrate the effectiveness and limitations of these schemes, comparing energy consumption and end-to-end delay performance.