• Japan’s SoftBank Corp has been planning its 6G strategy for years already
• The use of high-frequency spectrum is set to play a key role in next-generation cellular service delivery
• SoftBank has teamed up with Nokia to trial services in the 7GHz band in Tokyo

With its 6G future in mind, Japanese network operator SoftBank Corp has set up an outdoor trial of cellular service coverage in Tokyo using spectrum in the 7GHz band and network equipment from Nokia.  

The telco has been working on 6G concepts since at least 2017 and in 2021 it outlined a dozen key challenges for the next generation of cellular communications – see SoftBank outlines 12 challenges for 6G.

Since then it has invested a lot of time and effort in high altitude platform station (HAPS) connectivity options, such as the one recently unveiled with HAPS vehicle developer Sceye, and brokered 6G-related partnerships with the likes of Ericsson.

Now it has teamed up with Nokia for an outdoor trial of cellular connectivity using the 7GHz band, a centimetre-wave frequency that might be used for standards-based 6G communications. The specific band used in this trial – 7.125GHz to 8.4GHz – is scheduled to be discussed at the ITU-R’s World Radiocommunication Conference 2027 (WRC-27) as a potential 6G frequency, noted SoftBank.

For the trial, SoftBank is installing three 7GHz-compatible pre-commercial Nokia base stations, as well as pre-commercial end-user devices, in central Tokyo (the Ginza district), and “using massive MIMO technology to evaluate how 6G area coverage, comparable to 5G, can be deployed in urban areas,” it noted in this announcement.  

According to SoftBank, the 7GHz band is well suited for high-speed communication and reliable area coverage and is regarded as a “promising 6G solution” for dense urban environments that increasingly face signal penetration challenges due to building congestion.

The trial is designed to compare the coverage and radio characteristics of the 7GHz band with commercial 5G sub-6 (3.9GHz) “by co-locating 7GHz pre-commercial base stations next to existing 5G base stations on building rooftops,” noted the operator. “The goal is to use massive MIMO to establish contiguous coverage in the surrounding area.

Future testing will include both indoor and outdoor measurements within the trial zone, contributing to ongoing R&D for the commercialisation of 6G,” added SoftBank. 

The trial comes a few months after the 3GPP began the process that will lead to the  development of 6G specifications. For an initial meeting held in South Korea in March, industry stakeholders, including network operators and technology vendors, submitted 200 documents outlining different views of what 6G should encompass for consideration by the 3GPP working groups. 

SoftBank Corp was among the telcos to make a submission: It stressed the need for cooperation between 4G, 5G and 6G systems for a seamless transition to next-generation services and the reuse of existing frequency bands, among many other things. You can get the details of what SoftBank specified, outlines of the submissions made by other network operators, and an overall view of what major service providers are hoping 6G will deliver in our free-to-download Defining 6G Networks report, What do operators want?   

That’s just one of a series of Defining 6G Networks reports published by TelecomTV in recent months – you can find them all in our reports section as well as in our Defining 6G Networks channel.  

- Ray Le Maistre, Editorial Director, TelecomTV