Ambient Energy Sources, Applications and Ambient Energy Harvesting in Cognitive Radio

The future of digital communication is predicted as one of hyper connectivity powered by the Internet of things where every device is connected to other devises via a wireless network, where every object we use would be designed to become an information source, information that would be generated locally and used among other things to simplify our lives. Future from the perspective of energy in such devices would be to design those devises to also generate energy locally. What if we could utilize every possible energy source available to harvest energy From mechanical movements, thermal variations to using electromagnetic energy abundantly available in urban environments. Cognitive radio, defined as a radio that can adapt to its environment, based systems are the best answer to implement such networks. This literature review lists possible green energy sources for the purposes of ambient energy harvesting, their existing applications and the analyses the possibility of their implementation in cognitive radios.