Optimal, suboptimal and adaptive threshold policies for power efficiency of wireless networks

In this paper, we prove that the optimal power-efficient transmission policy, which ensures a desired throughput in a wireless network, is necessarily of threshold nature. Although detailed properties of this policy might be quite complicated, we show that it can be approximated by a suboptimal one, which is both simple and practical. This suboptimal policy may lead to substantial improvement in power-efficiency (compared to the widely used constant SNR policy), but at the expense of location-fairness. To alleviate this deficiency, we introduce an adaptive threshold policy and show that it is both relatively power-efficient and location-fair.