Achieving Energy Efficient Transmission in Wireless Body Area Networks for the Physiological Monitoring of Military Soldiers

In this paper, the energy consumption within a soldier worn wireless body area network (WBAN) is minimized by formulating and solving two optimization problems. In the first optimization problem, Karush-Kuhn-Tucker (KKT) optimality conditions are used to analytically determine the effect of jointly optimizing transmission power, payload size, and retransmissions on energy consumption for transmission along a link within a WBAN, under a packet error rate (PER) constraint. In the second optimization problem, sensor nodes with different source rates and placements on the body are configured to use variable transmission power, payload size, and retransmission in order to minimize the total energy consumption in the WBAN under a PER constraint. This is a non-linear non-convex problem that is converted into an easily solvable convex optimization problem using generalized geometric programming. The numerical results show that using the joint optimization approach for the transmission configuration parameters can increase the WBAN network lifetime by two folds when compared against a configuration that only optimizes transmission power and retransmissions.