Channel-Aware Opportunistic Transmission Scheduling for Energy-Efficient Wireless Links

The limited battery lifetime of a wireless device, which is directly related to the power consumption of the device, imposes a constraint on network performance. Thus, one of the most significant objectives in wireless communication networks is to improve the autonomy of the terminal devices. In this paper, we focus on the communication energy consumption, particularly on the data transmission part, which is one of the most energy-demanding operations of a wireless device. To satisfy a specified power level at the receiver, the transmission power consumption varies, strongly depending on the channel state of the wireless link. Considering that the communication is much more energy efficient when the channel conditions are good, we design and propose a novel distributed scheduler that opportunistically schedules data transmissions, with a view of minimizing the energy consumption of a wireless device and prolonging its battery lifetime. In fact, by exploiting the stochastic characteristics of the wireless channel, we postpone the communication up to an acceptable time deadline until we find the best expected channel conditions. The proposed time scheduling strategies are based on the optimal stopping theory, considering two minimization approaches for the consumption of transmission energy. Simulation results manifest that the proposed schemes offer significant energy efficiency and highlight their flexibility.