Propelled by the need to reduce the cost of caring for the ageing population, we observe an impetus towards enabling remote patient monitoring (mHealth) via low power medical sensor networks. A practical mHealth network consisting of several sensor modules located on the patients body needs to operate over long periods of time without any intervention. This requires efficient hardware and software design which will enable the battery powered sensor devices to operate efficiently and reliably with minimal energy consumption. This paper combines efficient antenna design with a cross layer energy efficient protocol to realize wireless body area networks (WBANs) where the main aim is to maximise network life time. Towards this goal, we demonstrate a high efficiency system design approach where the performance of WBANs are greatly enhanced.