An opportunistic sensor network approach to wide area environmental sensing

As the availability of frequency spectrum is constantly being reduced by the growing diffusion of portable applications, the need for high speed and low power wireless transmissions of large amounts of data has become a challenging topic, especially in scenarios like geographically spread environmental sensor networks. To deal with this, opportunistic transmission approaches, i.e. methods which leverage on spectrum sensing techniques to transfer data without the need for pre-assigned frequency slots, can be exploited; however, these methods often require computationally expensive spectrum estimation techniques, which may be unsuitable for low power devices. In this work, a spectrum sensing method which uses a simple and efficient chirp-based demodulation approach is presented: this technique allows preservation of both time and frequency resolution in spectrum estimation, while reducing computational load on sensor nodes, therefore making the deployment of an opportunistic environmental sensor network feasible.