With 5G Rollout Lagging, Research Looks Ahead to 6G

Amid a 5G rollout that has faced its fair share of challenges, it might seem somewhat premature to start looking ahead at 6G, the next generation of mobile communications. But 6G development is happening now, and it’s being pursued in earnest by both industry and academia.

Much of the future landscape for 6G was mapped out in an article published in March of this year in an article published by IEEE Communications titled “Toward 6G Networks: Use Cases and Technologies.”  The article presents the requirements, the enabling technologies and the use cases for adopting a systematic approach to overcoming the research challenges for 6G.

“6G research activities are envisioning radically new communication technologies, network architectures, and deployment models,” said Michele Zorzi,  a professor at the University of Padua in Italy, and one of the authors of the IEEE Communications article. “Although some of these solutions have already been examined in the context of 5G, they were intentionally left out of initial 5G standards developments and will not be part of early 5G commercial rollout mainly because markets are not mature enough to support them.”

The foundational difference between 5G and 6G networks, according to Zorzi, will be the increased role that intelligence will play in 6G networks. It will go beyond merely classification and prediction tasks as is the case in legacy and/or 5G systems.

While machine-learning-driven networks are now still in their infancy, they will likely represent a fundamental component of the 6G ecosystem, which will shift towards a fully-user-centric architecture where end terminals will be able to make autonomous network decisions without supervision from centralized controllers.

This decentralization of control will enable sub-millisecond latency as required by several 6G services (which is below the already challenging 1-millisecond requirement of emerging 5G systems). This is expected to yield more responsive network management.

To achieve this new kind of performance, the underlying technologies of 6G will be fundamentally different from 5G. For example, says Marco Giordani, a researcher at the University of Padua and co-author of the IEEE Communications article, even though 5G networks have been designed to operate at extremely high frequencies in the millimeter-wave bands, 6G will exploit even higher-spectrum technologies—terahertz and optical communications being two examples.

At the same time, Giordani explains that 6G will have a new cell-less network architecture that is a clear departure from current mobile network designs. The cell-less paradigm can promote seamless mobility support, targeting interruption-free communication during handovers, and can provide quality of service (QoS) guarantees that are in line with the most challenging mobility requirements envisioned for 6G, according to Giordani.

Giordani adds: “While 5G networks (and previous generations) have been designed to provide connectivity for an essentially bi-dimensional space, future 6G heterogeneous architectures will provide three-dimensional coverage by deploying non-terrestrial platforms (e.g., drones, HAPs, and satellites) to complement terrestrial infrastructures.”

Key Industry and Academic Initiatives in 6G Development:

• Both Samsung Electronics and LG have opened research centers for the development of essential technologies for 6G mobile networks.
• SK Telecom, Nokia, and Ericsson are collaborating together on a 6G-oriented research project.
• In its Canadian research center, Huawei is also looking towards the future in terms of wireless technology and has been reported to have started its own 6G research.
• Sony, Nippon Telegraph and Telephone Corporation (NTT), and Intel have announced plans to work together to develop 6G technology, which they expect could be rolled out as early as 2030.
• Tektronix and French research laboratory IEMN have developed 100 Gbps “wireless fiber” solutions. In a demonstration of the technology last year, they used a single carrier wireless link with a 100 Gbps data rate signal at 252 to 325 GHz, per the IEEE 802.15.3d standard.
• NTT has also demonstrated a 100 Gbps solution, but in its technology the carrier used a new principle, Orbital Angular Momentum (OAM) multiplexing, at 28 GHz with MIMO technology.
• In terms of academic and industry research cooperation, Finland has launched a flagship project built around nascent 6G technology, called 6Genesis. Researchers there have led the publication of several whitepapers discussing the key drivers and research questions prompting the development of 6G.
• Keysight Technologies, a provider of test and design solutions for telecommunication as well as other industries, is working on the 6Genesis flagship project.
• From a standardization point of view, the 3rd Generation Partnership Project (3GPP) will start concrete 6G standardization work from Release 20 (expected around 2025), and the European Commission is boosting research towards 5G long-term evolution.
• Among the academic players in this space, the University of Oulu in Finland is heading the already mentioned 6Genesis flagship initiative. 
• The NYU Wireless group is another leading academic research center pursuing 6G wireless and generations beyond that with cutting edge work in propagation measurement and modeling above 95 GHz.
• The Institute for the Wireless Internet of Things (WIOT) at Northeastern University is working on several active projects and research collaborations on 6G wireless systems.
• The mmWave Networking Group at the University of Padua has its own 6G research group and they are also working closely with the NYU Wireless Group.