Tracking of Remote IoT Devices by Satellite Assisted Geolocation

In previous work, it has been shown that massive machine type communication (mMTC) is possible with direct access to satellites in the geostationary earth orbit (GEO) using very compact Internet of Things (IoT) devices. The non-directive antenna of preferably small terminals restricts the transmit power to limit the interference for other satellites. The ultra-narrow-band (uNB)-IoT signals received by adjacent satellites are used in this paper for the geolocation of the transmitter. By this, the amount of data is reduced if the position of the sender shall be transmitted. We investigate the accuracy of remote geolocation of IoT devices transmitting short bursts at low power directly to GEO satellites. We further derive the geolocation error in latitudinal and longitudinal directions and calculate the required amount of information to be transmitted to achieve a desired resolution for the position information of the tracked object. For a typical scenario, we find that 35% to 63% of the transmitted bits could be saved, which results in a huge saving of transmit energy of battery powered small devices in the Internet of Remote Things (IoRT).