Fairness-Aware Scheduling Optimization for NB-IoT in LEO Satellite Networks Using a 3D Spherical Coordinate System

This article focuses on optimization problems in military scenarios of the narrow-band Internet of Things (NB-IoT)-low Earth orbit (LEO) satellite networks. A 3D model of the LEO satellite is presented using a spherical coordinate system, enabling the determination of a practical elevation angle for the ground-to-satellite channel model. This study aims to maximize the minimum average throughput by formulating an optimization problem that incorporates the association between IoT devices and LEO satellites. To solve this problem, an iterative algorithm based on successive convex approximation algorithms is proposed. Simulation results confirm the effectiveness of the proposed optimal approach and show up to 59.51% of effective throughput improvement compared to conventional approaches while ensuring fairness between IoT devices. In addition, the article highlights important findings through top-view 2D and 3D snapshots, demonstrating optimal decisions using the proposed method.