Energy efficient scheduling for delay constrained communication in wireless body area networks

Delay constraint and sensor energy consumption requirements are two core issues for e-healthcare applications in wireless body area networks. In this paper, we investigate the data transmission scheduling problem to utilize the sleep and opportunistic transmission for energy efficiency, while guaranteeing the worst-case delay for medical data transmission. To achieve sensor energy saving by exploiting propagation channel quality with a deterministic delay requirement poses challenges in developing a scheduling policy. We address this problem using a Lyapunov optimization formulation and propose a two-step scheduling algorithm. We prove that the algorithm can provide worst-case delay guarantee under certain conditions. Theoretical analysis and simulation results are presented to demonstrate the tradeoff between the transmission delay and energy consumption.