energy-efficient communication in next generation rural-area wireless networks
White space frequencies are highly attractive for long-distance communication due to greater signal propagation. The lack of standards and licensing issues with increased flexibility provided by the cognitive radio allow for sophisticated customized solutions for white spaces. Rural-area networks are seen as the main beneficiaries and white spaces communication is expected to outperform current wireless solutions in this domain. However, rural networks often have to rely on a constrained energy budget and highly benefit from energy-efficient operation. We investigate the efficiency of flexible wireless transmission over long-distance white space links. We theoretically and experimentally examine the impact of channel width, modulation and coding and transmission amplitude on energy consumption. From our findings we derive the physical layer parameter settings that achieve energy optimality and develop PowerRate, a protocol that dynamically adjusts transmission parameters according to channel state. We implement PowerRate in GNUradio and evaluate its energy-saving potential in various fading environments.
wireless networks white spaces rural communication