True 5G is just around the corner: Tokyo Tech and Rakuten Mobile

After years of exciting headlines, “true 5G” may finally be upon us.

On July 4, Rakuten Mobile successfully verified data transfer on a 5G standalone (5G SA) mobile network with collaboration from Tokyo Institute of Technology (Tokyo Tech), on the grounds of the university’s Ookayama campus in southern Tokyo.

“Standalone” 5G: What’s the big deal?

The imminent age of 5G has been heralded in industry headlines for several years now, and many mobile carriers around the globe ― including Rakuten Mobile ― have already launched their 5G services. So what exactly was Rakuten Mobile verifying?

Many of the exciting headlines surrounding 5G and its futuristic potential hinge on this holistic approach. Performing remote surgery, for example, requires the ultra-low-latency only possible on a standalone 5G network.

The word “standalone” gives most of the game away. Most of the 5G services that have been deployed around the world to date are “non-standalone,” essentially 5G base stations connected to a 4G network. A standalone 5G network, meanwhile, is built with 5G technology throughout, from the core network to the radio access network (RAN).

With the overwhelming majority of the world’s networks still running on 4G architecture, this transitionary step of employing 5G tech on top of existing networks is an essential one. By doing so, carriers can offer next-gen speeds while leveraging existing infrastructure as they prepare to transition the rest of their network to standalone 5G.

But if tacking 5G tech onto 4G architecture can produce such great speeds, why is standalone 5G necessary at all? The answer to this question lies in the fact that 5G isn’t just about pure speed.

While 5G NSA can provide excellent upgrades to a network’s speed, it can’t take full advantage of the high capacity, low latency and massive multi-connectivity that 5G can realize. In order to do this, everything from the core network outwards needs to be built around 5G.

Many of the exciting headlines surrounding 5G and its futuristic potential hinge on this holistic approach. Performing remote surgery, for example, requires the ultra-low-latency only possible on a standalone 5G network. Meanwhile, IoT applications are demanding more and more connections to work with more and more devices ― another capability of standalone 5G.

Pushing new boundaries, setting new standards

Through collaboration between Tokyo Tech and Rakuten Mobile, data transmission was carried out using a 5G SA-compatible device on the 5G network at the campus, verifying the stable operation of 5G SA. Rakuten Mobile will leverage the results of the verification to improve the quality of its 5G SA network and in preparations for the full launch of commercial services.

The work is part of the initiatives commissioned by Japan’s New Energy and Industrial Development Organization (NEDO) to Rakuten Mobile under the research theme of “developing post-5G information communications systems.” For these projects, the operator is carrying out technical development related to the enhancement of virtualized RAN for 5G networks and the automation of network operations.

The Rakuten Mobile team has trials of cutting-edge mobile technologies planned for the near future. Network slicing, for example, allows single network connections to be split into multiple virtual connections through network virtualization, so that different capacities can be assigned for different types of traffic. Edge computing ― in which processing is carried out close to the user (on the “edge” of the network) for low latency ― is also on the team’s radar.

Rakuten Mobile has built its network architecture with an eye to the age of 5G and beyond. With the successful verification of 5G SA data transmission under its belt and the deployment of 5G SA functions in parts of its commercial network underway, the age of “true 5G” is looking closer than ever.