Field experiments for developing transmission control based on weather estimation in an environmental wireless sensor network

One of the problems affecting sensor networks for natural environments is the attenuation of radio waves due to high humidity, and the attenuation is worst in the case of a 2.4 GHz radio wave. We are developing a transmission control method that estimates communication environment fluctuations caused by changes in the natural environment. This paper discusses a transmission performance in wireless sensor networks in terms of correlations between wireless transmission performance and environmental conditions observed in filed experiments. Measurements were made with sensor nodes equipped with a weather sensing device at an experimental filed of the university, Field Museum (FM) Tamakyuryo in Tokyo. During a one-week experiment, measurements of some parameters, a Throughput, signal strength, humidity, and atmospheric pressure were taken in the field. The results confirmed that increasing humidity definitely decreased the throughput. Temporal changes of the atmospheric pressure during the ongoing measurements will foresee short-term weather changes, which would enable to keep the transmission in control under the foreseen weather conditions.