But what is 6G?

New York University and Nokia have, since 2014, held an annual technical symposium, The Brooklyn 5G Summit, on the NYU campus. It attracts the world’s top wireless researchers from industry and academia. It was through the Brooklyn 5G Summit that the idea of using the mmWave band transitioned from arcane research to commercial realization in 5G. This year’s event, held virtually, was re-titled “The 6G Summit”.

From an engineering perspective, 5G – and especially 5G Standalone (SA) - was an opportunity to start from a clean sheet of paper to define the global mobile architecture, air interface, radio access network, core network and operations and business support systems.  In addition to improving upon the data rates, spectral efficiency, latency, and scaling ability of 4G LTE Advanced, 5G adds mmWave radios, radio techniques like beamforming, and multi-user MIMO with Network Slicing, precision location/navigation/timing, multi-user MIMO, pervasive use of artificial intelligence, automation, open radio access networks, and cloud-native/microservices based software architectures.

At the recent 6G Summit, one researcher proposed a 6G vision that is simply more of the same -- yet faster data rates, greater spectral efficiency, more IoT devices, lower latency, higher location accuracy, higher reliability, more AI, more automation, more cloudification etc. -- raising the question of “what’s the point”?

However, 6G should be much more than a better 5G, and researchers are already working on several novel and important ideas:

• Terahertz spectrum. Just as 5G allows operators to harvest bandwidth in the 24-100 GHz region of the spectrum, 6G will open spectrum from 100 GHz to perhaps 250 GHz. This means yet more capacity at short range as growing traffic overwhelms the capacity of the mmWave bands. The physics of this are challenging, but according to recent research at NYU, not impenetrable.
• Integrated sensing and communication. The 6G communications network may also become a sensing network, with communication waveforms also serving to measure physical objects and the environment.
• Advanced materials. Metamaterials show promise in antennas and active reflectors. New semiconductor materials systems may be needed for Terahertz radio components and energy savings.
• Quantum entanglement. This has been experimentally applied to high accuracy timing synchronization, a necessary supporting function for some advanced radio techniques like COMP.
• New ways to do Spectrum sharing. Regulators will have to drive more efficient utilization of low- and mid-band spectrum by taking away exclusivity without creating harmful interference. The experience gained in the US from the 3.5GHz CBRS band promises opportunities for other forms of coordinated shared spectrum regimes.
• Holographic communications. One answer to the question of what can be done with yet more capacity, higher data rates and lower latency is holographic communications. Holographic projection is now becoming practical. Its actual traffic characteristics remain a research item, and significant compression may leave it in the 5G realm.
• Large-scale Digital Twins. The idea of a real-time synchronized computational model of an object – possibly even a human – has emerged, in the context of 5G, for analytics, prediction, and preemptive action. 6G could make it easier to handle the voluminous real time sensor data needed to synchronize the state of digital twins, especially for large scale complex objects such as the complete environment of a smart city. New approaches to fusing sensing and networking may be needed.

At this point, 6G is a blank slate, defined mostly by the perceived imperative to have the next ‘G’ arrive on a 10-year cadence. Research in industry, academia, government, and industrial/academic partnerships is beginning to fill in the blanks as to what is possible, ultimately leading to use cases and value propositions.

Strategy Analytics is beginning to track how 6G may take form in the coming years.