Performance Analysis of SAGIN from the Relay Perspective: A Spherical Stochastic Geometry Approach

2025-07-27

AI Summary

This work addresses the performance bottleneck of high-altitude platforms (HAPs) acting as relay nodes in satellite–air–ground integrated networks (SAGIN). To tackle the challenges of 3D dynamic topology and spherical-space interference modeling, we propose the first analytical framework based on spherical stochastic geometry. Our method introduces three novel metrics—average access rate, average backhaul rate, and backhaul rate exceedance probability—and derives closed-form expressions for end-to-end performance, significantly reducing evaluation complexity. We obtain an exact analytical solution for the backhaul rate exceedance probability, revealing how satellite constellation topology governs system performance. Furthermore, we quantify the minimum HAP transmit power required to guarantee short-term and long-term rate requirements. The results provide a tractable, scalable theoretical foundation for HAP relay deployment in SAGIN.

Technology Category

• Planning, Routing, and Scheduling: Optimization of Spatio-temporal Systems
• Constraint Satisfaction and Optimization: Satisfiability
• Reasoning under Uncertainty: Stochastic Optimization

Application Category

• Systems and Infrastructure for Web, Mobile and WoT: Web performance, measurement, and characterization
• Graph Algorithms and Modeling for the Web: Algorithms and analysis for heterogeneous, signed, attributed, multi-relational, temporal, higher-order, and annotated Web-related graphs
• Security and Privacy: Large-scale security measurements

Abstract

In recent years, the satellite-aerial-ground integrated network (SAGIN) has become essential in meeting the increasing demands for global wireless communications. In SAGIN, high-altitude platforms (HAPs) can serve as communication hubs and act as relays to enhance communication performance. In this paper, we evaluate network performance and analyze the role of HAPs in SAGIN from the relay perspective. Based on this unique perspective, we introduce three metrics to evaluate the performance, named the average access data rate, the average backhaul data rate, and the backhaul rate exceedance probability (BREP). Considering the need for dynamic topology and interference analysis, we choose spherical stochastic geometry (SSG) as a tool and derive analytical expressions for the above metrics to achieve low-complexity performance evaluation. Specifically, we provide a closed-form expression for the end-to-end performance metric BREP. Given that there is no existing literature in the SSG field studying networks from a relay perspective, we specifically investigate the impact of satellite network topology on performance in our numerical results to further highlight the advantages of the SSG framework. Additionally, we analyze the minimum HAP transmission power required to maintain both short-term and long-term data rate demands.

Problem

• Evaluating HAPs' relay role in SAGIN performance
• Deriving low-complexity metrics using spherical stochastic geometry
• Analyzing satellite topology impact on network performance

Innovation

• Uses spherical stochastic geometry for analysis
• Introduces three novel performance metrics
• Provides closed-form BREP expression