The Road Towards 6G: A Comprehensive Survey (2102.01420v1)

Abstract: As of today, the fifth generation (5G) mobile communication system has been rolled out in many countries and the number of 5G subscribers already reaches a very large scale. It is time for academia and industry to shift their attention towards the next generation. At this crossroad, an overview of the current state of the art and a vision of future communications are definitely of interest. This article thus aims to provide a comprehensive survey to draw a picture of the sixth generation (6G) system in terms of drivers, use cases, usage scenarios, requirements, key performance indicators (KPIs), architecture, and enabling technologies. First, we attempt to answer the question of "Is there any need for 6G?" by shedding light on its key driving factors, in which we predict the explosive growth of mobile traffic until 2030, and envision potential use cases and usage scenarios. Second, the technical requirements of 6G are discussed and compared with those of 5G with respect to a set of KPIs in a quantitative manner. Third, the state-of-the-art 6G research efforts and activities from representative institutions and countries are summarized, and a tentative roadmap of definition, specification, standardization, and regulation is projected. Then, we identify a dozen of potential technologies and introduce their principles, advantages, challenges, and open research issues. Finally, the conclusions are drawn to paint a picture of "What 6G may look like?". This survey is intended to serve as an enlightening guideline to spur interests and further investigations for subsequent research and development of 6G communications systems.

• The paper identifies key drivers for 6G by detailing technological requirements and KPIs that surpass current 5G capabilities.
• It examines emerging use cases such as holographic communications, AI-driven optimization, and tactile internet to meet ultra-low latency and high bandwidth demands.
• It reviews global research efforts and technological enablers like terahertz frequencies and non-terrestrial networks that are crucial for realizing 6G connectivity.

Overview of "The Road Towards 6G: A Comprehensive Survey"

The paper "The Road Towards 6G: A Comprehensive Survey" delivers a meticulous examination of the evolution from fifth generation (5G) to sixth generation (6G) mobile communication systems. The authors provide an analysis grounded in the historical context, foundational technologies, and projected needs and capabilities of future networks. The document serves as a detailed survey of 6G’s driving factors, technical requirements, potential use cases, state-of-the-art research efforts, and enabling technologies. This paper is particularly relevant for researchers and industry professionals planning for advancements beyond the current network capabilities, thereby establishing it as a critical reference point for 6G development.

Drivers and Necessity for 6G

The authors assert that while 5G is still actively being deployed, the demand for data and new technological opportunities necessitate a consideration of 6G systems. A significant driver for 6G is the anticipated explosive growth in mobile traffic, projected to exceed 5016 exabytes per month by 2030, demanding connectivity solutions far surpassing the current capabilities of 5G. Beyond mere increases in data traffic, new technological trends, such as AI, blockchain, and the Internet of Things (IoT), emphasize the importance of versatile and reliable communication networks encouraged by 6G initiatives.

Use Cases and Requirements

The paper identifies multiple use cases that could benefit from the enhanced capabilities of 6G, including holographic communications, pervasive intelligence, tactile internet, and intelligent transport systems. These use cases carry requirements that exceed those of 5G, demanding ultra-low latency, high reliability, substantial bandwidth, and global connectivity. Novel technical requirements for 6G are described using KPIs like peak data rates of up to 1 terabit per second, user-experienced data rates, and latency measured in microseconds. The paper argues that only innovative approaches and substantial technology upgrades can meet these stringent demands.

Technological Enablers

Several key technologies likely to enable the dawn of 6G are discussed in depth. For instance, the exploration of frequencies in mmWave, terahertz, and optical bands is highlighted as critical to providing the necessary bandwidth for future data demands. The development of large-scale satellite constellations and non-terrestrial networks, which offer ubiquitous coverage, serves as a cornerstone for ensuring global connectivity. Moreover, advanced networking paradigms, including network slicing, software-defined networks, and edge computing, are expected to provide low-latency and highly customizable connectivity tailored precisely to specific use cases. AI’s role in optimizing these systems also presents transformative opportunities.

Existing Efforts and Roadmaps

The paper goes on to outline the current global efforts in 6G research and development, noting significant European and international projects aiming to explore and implement key technologies. It forecasts a potential roadmap where research, specification, standardization, and implementation coalesce to enable the first 6G networks by the early 2030s. Nonetheless, a distant yet promising possibility remains for overcoming the deep technical challenges that accompany such transformative goals.

Conclusion

Ultimately, the paper suggests that 6G will not merely extend the capabilities of 5G but transform communication networks into integral intelligence platforms capable of supporting life-altering technologies. Such networks would combine ubiquitous computing, communication, sensing, and intelligence to ignite the next wave of societal and technological evolution, making them crucial for both academia and industry to consider presently.

In summary, this paper not only explores the feasibility and need for a new generation of mobile communication but also sets a robust foundational framework for the incremental steps needed to transform our modern information landscape with 6G technologies.