**Author details**

capability have different low-power or sleep modes to save energy during times of inactivity. The management of these modes is very important in relation with an energy harvesting strategy allowing to refill the energy storage device during these periods of low activity [16]. Considering the environmental sensor network, energy harvesting and low-power RF SoC, a

**Figure 7.** IoNaT node. SD: Energy storage device. ECC: Energy conditioning circuit. RF: RF transceiver.

It is important to observe that as the data coming from IoNaT nodes would be sporadic and with an extremely low data rate, potential technologies to implement an IoNaT-node network may be those based on the IEEE 802.15.4 physical radio specification [39], particularly, for example, ZigBee [40] that features low-power and low-bandwidth capabilities. Another potential technology for the same purpose would be LoRaWAN [41] that is a low-power widearea network (LPWAN) that features low-power and low-bandwidth capabilities, but is still capable to sustain long-range wireless connections. However, LoRaWAN only implements

An Internet of Natural Things (IoNaT) approach has the potential to be fully developed and gain the same attention as the IoT in a near future. However, to obtain such a development and at the same time, to be an environment-friendly option, it is mandatory to avoid using chemical batteries and to use technologies based on energy harvesting along with wireless sensor networks. In the context of IoNaT, it will be possible to take advantages of modern technology and, as a consequence, to incorporate services as environmental monitoring for impact assessments of human activities, animal surveillance, plantation monitoring and other

One of the authors (C.P.) would like to thank the Federal University of Paraiba and the University of Washington Tacoma for providing the opportunity to develop his research work

This work was partially funded by the UWT Endowment in Engineering Systems (O.B.), by the Brazilian Center for Scientific Research (CNPq) through the Foreign Visiting Professor Program

possible structure for an IoNaT node is shown in **Figure 7**.

star topology.

36 Energy Systems and Environment

**5. Conclusion**

services related to natural environments.

**Acknowledgements**

in the United States.

Cleonilson Protasio de Souza<sup>1</sup> \* and Orlando Baiocchi<sup>2</sup>

\*Address all correspondence to: protasio@cear.ufpb.br

1 Federal University of Paraíba, João Pessoa, PB, Brazil

2 University of Washington Tacoma, Tacoma, WA, EUA
