Wireless environmental sensor networking with analog scatter radio and timer principlesWireless environmental sensor networking with analog scatter radio and timer principles Peer-Reviewed Journal Publication Δημοσίευση σε Περιοδικό με Κριτές 2015-10-262014enEnvironmental variables monitoring with wireless sensor networks (WSNs) is invaluable for precision agriculture applications. However, the effectiveness of existing low-power, conventional (e.g., ZigBee-type) radios in large-scale deployments is limited by power consumption, cost, and complexity constraints, while the existing WSN solutions employing nonconventional, scatter-radio principles have been restricted to communication ranges of up to a few meters. In this paper, the development of a novel analog scatter-radio WSN is presented, that employs semipassive sensor/tags in bistatic topology (i.e., carrier emitter placed in a different location from the reader), consuming <;1 mW of power, with communication range exceeding 100 m. The experimental results indicate that the multipoint surface fitting calibration, in conjunction with the employed two-phase filtering process, both provide a mean absolute error of 1.9% environmental relative humidity for a temperature range of 10 °C-50 °C. In addition, the energy consumption per measurement of the proposed environmental monitoring approach can be lower than that of conventional radio WSNs. Finally, the proposed approach operational characteristics are presented through a real-world network deployment in a tomato greenhouse. http://creativecommons.org/licenses/by/4.0/IEEE Sensors Journal14103365 - 3376 Bletsas Aggelos Μπλετσας Αγγελος Kampianakis, E. Kimionis Ioannis Κιμιωνης Ιωαννης Tountas Konstantinos Τουντας Κωνσταντινος Konstantopoulos, C. Koutroulis Eftychios Κουτρουλης Ευτυχιος IEEE