Key 6G advances for Nokia, DOCOMO and NTT

Nokia, NTT DOCOMO and NTT have announced two key technological milestones in their 6G collaboration, originally launched in June 2022. The first is the implementation of artificial intelligence (AI) and machine learning (ML) into the radio air interface, effectively giving 6G radios the ability to learn. The second is the utilisation of new sub-terahertz (sub-THz) spectrum to dramatically boost network capacity.

The AI–native air interface and sub-THz spectrum are both critical research topics that Nokia, DOCOMO and NTT are exploring for future 6G networks. These technologies could pave the way for new immersive metaverse and extended reality (XR) experiences and a new generation of mobile applications. The companies have implemented both technologies as proofs of concept at Nokia Bell Labs in Stuttgart, Germany.

By pairing an AI-based learned waveform in a transmitter with a deep-learning receiver, researchers were able to design and implement a learning air interface that transmits data efficiently under many different scenarios. This AI/ML-based implementation significantly reduces signalling overhead, producing up to a 30% improvement in throughput.

In addition, the AI–native air interface will grant 6G networks the flexibility to adapt to the type of connection demanded by an application, device or user. For instance, a network in a factory can be optimised for industrial sensors at one moment and then reconfigured for robotic systems or video surveillance. In the public network, an AI-enhanced network can provide an optimised connection for a pedestrian in an XR session as well as an emergency vehicle travelling at high speed.

The sub-THz bands (100 GHz and above) have never been designated for cellular use because of their propagation characteristics, but new techniques such as beamforming could open up those frequencies to future 6G networks. These higher frequencies are well suited for high-accuracy radio sensing, which will likely be another key feature of 6G. In their proof of concept, the companies were able to demonstrate a 25 Gbps connection on a single 256QAM stream over a carrier frequency of 144 GHz using beamforming. Accessing the sub-THz bands would inject enormous capacity into 6G networks — not only will they improve overall capacity, they will allow 6G networks to support the most bandwidth-intensive future use cases requiring multi-gigabit average connections.

“For the 6G era, we are using communication as a starting point,” said Peter Vetter, President of Bell Labs Core Research, Nokia. “Networks will think, sense and act, and they will become the nexus point that bridges our digital and physical realities. DOCOMO and NTT share our 6G vision, and together we’re doing the fundamental research that will breathe life into that future.”

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