Computing in Integrated Terrestrial and Non-Terrestrial Networks: A Comprehensive Survey

TL;DR

ITNTN computing aims to provide ubiquitous, low-latency computing by integrating terrestrial and non-terrestrial networks. The paper surveys cloud, fog, and edge computing fundamentals, then reviews computing in terrestrial networks (ground, vehicular, IoT) and non-terrestrial networks (satellite, HAPS, UAV), before examining fully integrated ITNTN architectures. It highlights methodological trends, such as DRL, Lyapunov optimization, game theory, and DT/MARL frameworks, and discusses open issues including interoperability, energy efficiency, security, spectrum management, and business models. The work serves as a first comprehensive map of computing within ITNTN and guides future research toward full end-to-end integration.

Abstract

The rapid growth of Internet-of-things (IoT) devices, smart vehicles, and other connected objects is driving demand for ubiquitous connectivity and intensive computing capacity. 5G and upcoming 6G networks are crucial to meeting these demands and the fast-evolving services and applications. However, traditional terrestrial networks face limitations in coverage and capacity. Integrated Terrestrial and Non-Terrestrial Networks (ITNTN) are emerging to address these challenges. In essence, ITNTN combines ground-based infrastructure with aerial, space, and water surface networks to provide seamless connectivity and computing resources anytime, anywhere. Given the stringent quality-of-service (QoS) of future services, edge computing will be an inseparable component of ITNTN. Consequently, we dive in this survey into current efforts of integrating cloud/fog/edge computing into ITNTN layers to facilitate stringent QoS services and address the data processing needs of modern applications. Since there have been only limited and partial efforts in integrating computing functionalities within ITNTN, we aim to extend the discussion to the full integration of computing and identifying the challenges and future research directions to achieve it.