Fast Time-of-Visibility Estimation for Real-Time Direct-to-Satellite IoT Connectivity

Global IoT connectivity remains challenged by the limited coverage of terrestrial networks and issues in the existing architectures for Direct-to-Satellite (DtS) IoT, where real-time data transfer is a problem due to the lack of inter-satellite links (ISLs), thus producing latency and low data rates. We propose, in this work, a new Hybrid Multihop Direct-to-satellite IoT architecture, denoted HMDI, that offers near real-time IoT connectivity via LEO satellites deprived from ISLs. Our proposed method is based on relaying critical IoT messages from one satellite to another ground-based IoT device, which relays the data to other satellites until the message reaches a satellite that has a direct line of sight to a ground station. The evaluation of our approach is expected to demonstrate significant improvements in connectivity and latency.