Changing paradigms for green cellular networks: The case of delay-tolerant users

In this paper, we propose to reduce the energy consumption of cellular networks by leveraging coordinated cell switching algorithms with user cooperation. Cell switching consists in deactivating some base stations in periods of low load in order to reduce the power consumption, while the coverage is provided by remaining active base stations. We propose to maximize these periods of low power consumption by delaying the start of some user services. We present two different strategies to control the cell switching considering the users delay tolerance and we evaluate their performance in the well known Network Simulator 3 (NS-3). We show how appropriate thresholds selection leads to bound the user waiting time, and we highlight how the system load estimation is important for this purpose. Finally, we show that power reductions from 18% to 72% are possible for different offered load levels in the network when using the proposed algorithms.