Unlocking DtS-IoT Medium Access Through the Massively Scalable Distributed Queuing Protocol

Direct-to-satellite Internet of Things networks (DtSIoT) offer a cost-effective way to establish global communication between IoT devices and low Earth orbit satellites. However, budget-conscious DtS-IoT systems face resource constraints in user, space, and ground segments. An increasing limitation in the performance of satellite IoT networks is observed in the link layer. This stems from the prevalent use of ALOHA-based MAC protocols, leading to constraints in managing larger networks. The requirements of DtS-IoT deployments with extensive network sizes amplify the growing demands for energy-efficient and scalable MAC protocols. In this paper, we formulate a new energy-efficient MAC protocol, Massively Scalable Distributed Queuing (MSDQ), inspired by components of the Distributed Queuing (DQ) protocol and the RESS-IoT protocol. Utilizing FLoRaSat, a realistic LoRa-based DtS-IoT network simulator, we showcase the performance of MSDQ, DQ, and RESS-IoT. Results indicate that MSDQ outperforms DQ by 2.2 times the throughput and 19 times the node energy efficiency of RESSIoT. These findings highlight the performance gap of existing MAC protocols for large and geographically distributed DtSIoT systems.