This paper applies a robust anti-windup (AW) based control scheme to optimise throughput rate for an 802.15.4 wireless body area network (WBAN) that is subject to naturally occurring input saturation constraints. The technique uses an intuitively appealing two step design procedure. Firstly, a robust H-infinity loop-shaping linear controller is designed providing nominal (un-saturated) robust performance. Then Weston-Postlethwaite AW compensation techniques are used to minimise the adverse effects of any control input non-linearities on closed loop performance. The methodology provides guaranteed quality of service (in this context taken to mean that sufficient data is always available to reassemble the required biometric waveforms, e.g. ECG) while concurrently minimising power consumption over an extended usage period. This joint robust performance question is validated on an experimental mote based 802.15.4 wireless sensor network.