Wireless energy harvesting from ambient sources for cognitive networks in rural communities

Cognitive Radio Networks (CRN) offer a solution to work with low interference in electromagnetically noisy environments such as in the proximity of TV/Radio stations or high voltage power lines in rural communities. However, the extra sensing requirement of CRN nodes results in high energy consumption. This lowers battery life, which is especially problematic in cognitive sensor networks. To counter this problem, in this paper, we propose a wireless energy harvesting (WEH) scheme to harvest RF energy from the ambience. We modify the popular energy efficient MAC protocol LEACH (Low Energy Adaptive Clustering Hierarchy) to incorporate energy harvesting. Our simulation results show RF energy harvesting is feasible only when the transmission power of the source is above 10 kW. This contrasts many papers that suggest to harvest energy from other low power wireless transmitters. Our work also shows that RF energy harvesting CRN can potentially benefit rural communities located within the high power radiation range.