Wind Energy Dependent Rate Adaptation for Roadside Units

In this paper, we propose a rate adaptive technique for wind powered standalone (off-grid) roadside units (RSUs) in a motorway environment. In a non-rate adaptive system, the transient nature of renewable wind energy causes the RSUs to either transmit at full data rate or not transmit at all based on the availability of sufficient energy. In rate adaptation, the data rate of an RSU adapts according to the available energy. Further, the RSU saves transmission energy by operating at a lower data rate, even when enough energy is available. The saved energy, in turn, is used to maintain the data rate during energy deficiency, thereby minimizing outage and improving the quality of service (QoS). The performance analysis shows that the wind energy dependent rate adaptive RSU delivers a more energy efficient service with acceptable quality compared to a non-rate adaptive deployment in a renewable energy solely powered RSU. The proposed rate adaptive algorithm can be as well deployed to wind-powered communication base stations (BSs) and sensor networks.