Joint Sleep Scheduling and Opportunistic Transmission in Wireless Body Area Networks

E-healthcare systems of Wireless Body Area Network (WBAN) promise enormous change in future healthcare industry. The system generally consists of multiple sensor nodes that monitor various medical signals and deliver data to a network coordinator for further processing. One of the major issues of such systems is energy efficiency, owing to the limited power supply and difficult replacement of batteries in some implanted sensors. Hence, developing an energy-efficient scheduling policy to prolong sensors' lifetime brings great significance to a WBAN. In this paper, we investigate the problem with Lyapunov optimization technique and propose a dynamic scheduling policy including sleep scheduling and opportunistic transmission, which takes into account time-varying channel condition. We demonstrate that our policy can push the energy consumption arbitrarily close to the global minimum solution while sustaining the network stability.