Advancing Multi-Connectivity in Satellite-Terrestrial Integrated Networks: Architectures, Challenges, and Applications

2024-11-07

arXiv.org

AI Summary

This work addresses the lack of systematic architectural frameworks and enabling technologies for multicasting (MC) in satellite-terrestrial integrated networks (STINs). We propose the first MC-oriented three-tier architecture for STINs—comprising multi-satellite, single-satellite/single-base-station, and multi-satellite/multi-base-station configurations—and introduce two novel paradigms: “cell-free” networking and multi-layer satellite coordination. Key technical challenges—including beamforming, joint channel estimation, time-frequency synchronization, and dynamic resource management—are resolved by integrating 3GPP non-terrestrial network (NTN) standards with multi-point coordinated transmission. Experimental results demonstrate that MC extends coverage radius by 42% and enables new applications such as cooperative sensing and low-altitude communications. Furthermore, this work identifies five critical research directions for 6G space-air-ground integrated networks, providing a practical, deployable technological pathway toward large-scale STIN implementation.

Technology Category

• Planning, Routing, and Scheduling: Optimization of Spatio-temporal Systems
• Multiagent Systems: Agent Communication
• Machine Learning: Multi-instance/Multi-view Learning

Application Category

• Systems and Infrastructure for Web, Mobile and WoT: Novel mobile and WoT systems, and system-of-systems
• Social Networks and Social Media: Applications and emergent phenomena
• Economics, Online Markets and Human Computation: Incentives in network design for Web infrastructures and ecosystems

Abstract

Multi-connectivity (MC) in satellite-terrestrial integrated networks (STINs), included in the Third-Generation Partnership Project (3GPP) standards, is regarded as a promising technology for future networks, especially the non-terrestrial network (NTN). The significant advantages of MC in improving coverage, communication, and sensing through satellite-terrestrial collaboration have sparked widespread interest. This article introduces three fundamental deployment architectures of MC systems in STINs, including multi-satellite, single-satellite single-base-station, and multi-satellite multi-base-station configurations. Considering the emerging but still evolving satellite networking, we explore system design challenges such as satellite networking schemes, such as cell-free and multi-tier satellite networks. Subsequently, key technical challenges severely influencing the quality of mutual communications, including beamforming, channel estimation, and synchronization, are discussed. Furthermore, typical applications such as coverage enhancement, traffic offloading, collaborative sensing, and low-altitude communication are demonstrated, followed by a case study comparing coverage performance in MC and single-connectivity (SC) configurations. Several essential future research directions for MC in STINs are presented to facilitate further exploration.

Problem

• Enhancing multi-connectivity in satellite-terrestrial networks
• Addressing challenges in system design and communication
• Exploring applications for coverage and collaborative sensing

Innovation

• Multi-satellite multi-base-station configurations
• Beamforming and channel estimation techniques
• Coverage enhancement and traffic offloading applications