Direct Access to GEO Satellites: An Internet of Remote Things Technology

Satellites could guarantee ubiquitous service for devices in the Internet of Things (IoT) that are at remote locations without terrestrial services. The direct access of small and power-efficient terminals to satellite networks enables new services without the need of any terrestrial infrastructure. So far, the direct access to satellites in the geostationary earth orbit (GEO) has not been considered at higher frequency bands, where sufficient spectrum is available for massive machine type communication (mMTC). This paper analyzes the main hurdles of such a link and presents a novel waveform called Unipolar Coded Chirp-Spread Spectrum (UCSS) that enables ultra-narrow-band (uNB) communication with random multiple access between devices in the Internet of Remote Things (IoRT) and GEO satellites. We analyze UCSS by simulations and present a successful over-the-air transmission with a testbed operating at Ku-band. By that, it is verified that uNB mMTC via satellite is possible using the currently available resources in space.