[Paper Review] A Comprehensive Survey on 6G Networks:Applications, Core Services, Enabling Technologies, and Future Challenges

Amin Shahraki, Mahmoud Abbasi+2 more|arXiv (Cornell University)|Jan 29, 2021

Advanced Wireless Communication Technologies118 references101 citations

TL;DR

This survey comprehensively reviews 6G networks, outlining motivations beyond 5G, KPIs, use-cases, and enabling technologies, along with open challenges and future directions.

ABSTRACT

Cellular Internet of Things (IoT) is considered as de facto paradigm to improve the communication and computation systems. Cellular IoT connects massive number of physical and virtual objects to the Internet using cellular networks. The latest generation of cellular networks, e.g. fifth-generation (5G), use evolutionary and revolutionary technologies to notably improve the performance of wireless networks. However, given the envisioned new use-cases, e.g., holographic communication, and the ever-increasing deployment of massive smart-physical end-devices in IoT, the volume of network traffic has considerably raised, and therefore, the current generation of mobile networks cannot wholly meet the ever-increasing demands. Hence, it is envisioned that the next generation, sixth generation (6G) networks, need to play a critical role to alleviate such challenges in IoT by providing new communication services, network capacity, and ultra-low latency communications (uRLLC). In this paper, first, the need for 6G networks is discussed. Then, the potential 6G requirements and trends, as well as the latest research activities related to 6G are introduced e.g., Tactile Internet and Terahertz (THz). Furthermore, the key performance indicators, applications, new services, and the potential key enabling technologies for 6G networks are presented. Finally, several potential unresolved challenges for future 6G networks are presented.

Motivation & Objective

• Explain the need for a new generation beyond 5G to support growing IoT and novel use-cases.
• Detail 6G requirements, trends, KPIs, and service classes.
• Summarize research activities and organizational efforts shaping 6G.
• Identify potential enabling technologies and architectural considerations for 6G.
• Highlight unresolved challenges and future research directions.

Proposed method

• Review and synthesize existing literature on 6G from multiple survey sources.
• Categorize 6G aspects into requirements, trends, KPIs, use-cases, and services.
• Present a structured comparison of related surveys (Table I) to position this work.
• Outline evolving technologies and 6G research initiatives (ITU FG NET-2030, 6Genesis, TERRANOVA, etc.).
• Propose a comprehensive view that covers enabling technologies and 3D coverage, LISs, AI, THz, and beyond.

Experimental results

Research questions

• RQ1 Is there a need for a new mobile network generation beyond 5G, and why?
• RQ2 What are the fundamental 6G requirements and trends relative to 5G?
• RQ3 What are the most recent research activities and organizations driving 6G?
• RQ4 What are the critical 6G KPIs and potential applications?
• RQ5 What new service classes and enabling technologies are essential for 6G, and what challenges remain?

Key findings

• 6G is expected to provide broader frequency bands (potentially 73 GHz, 140 GHz, 1 THz, 3 THz) and ultra-low latency (end-to-end < 1 ms).
• New service classes include massive URLLC, eMBB, and Massive eMBB to meet high reliability, high data rate, and massive connectivity needs.
• Prominent 6G use-cases include holographic communication, industrial automation, e-health, tactile Internet, AR/VR, and private 6G networks.
• A range of enabling technologies is identified, such as Terahertz communications, AI-driven network management, LIS/IRS, 3D coverage, and integrated satellite/terrestrial networks.
• The paper discusses ongoing research initiatives (ITU FG NET-2030, 6Genesis, TERRANOVA, NYU WIRELESS, etc.) and outlines key challenges and future research directions.