Energy-conscious prototype for enabling multi-protocol wireless communications

In this paper, we present a novel hardware prototype implementation of a wireless communication system capable of automatically selecting one of several available commercial standards in order to minimize energy utilization while simultaneously achieving reasonable data rate performance. Without loss in generality, two wireless standards were employed in the prototype implementation, namely: ZigBee and WiFi. These standards were chosen due to their complementary characteristics with respect to data bandwidth and energy efficiency. At the core of the prototype implementation is a decision-making module designed to automatically select the most suitable wireless standard for data transmission based on the instantaneous network load and the operating conditions of the wireless platform, such as battery life. The prototype implementation was evaluated across several data transmission scenarios, including file transfers, web browsing, streaming media and text messaging. By leveraging the concepts of sensing and adaptation often employed in cognitive radio, the prototype system monitors and selects the lowest power intensive wireless protocol while still maintaining an acceptable quality of service for the desired application. Even though performance transparency could not be sacrificed for power efficiency, experimental validation of this network design shows substantial energy savings: more than a 30% reduction in energy consumption of the wireless interfaces is possible, leading to a substantial increase in the effective battery lifetime of a energy-limited wireless networking device.