Online Uplink Scheduling for Multi-User LEO Satellite IoT Networks

Low-Earth-orbit (LEO) satellite constellations are emerging as a promising infrastructure for uplink-dominated Internet of Things (IoT) services. However, rapid satellite mobility leads to highly time-varying user-satellite associations, frequent handovers, and limited onboard processing capacity, which jointly complicate uplink scheduling design. Moreover, uplink tasks often span multiple time slots, resulting in strong cross-slot coupling due to task queue evolution and association switching costs. This paper investigates online uplink scheduling for multi-user LEO satellite IoT networks under time-varying visibility and switching costs. We formulate a cross-slot uplink scheduling model that captures dynamic association, onboard processing constraints, and task backlog evolution. To address the resulting complexity, we propose a Lyapunov-based primal-dual online scheduling algorithm that operates without future system information and guarantees queue stability. Simulation results demonstrate that the proposed approach effectively reduces uplink delay, improves satellite load balancing, and suppresses unnecessary handovers compared with representative baseline schemes.