LIVE FROM LTE WORLD SUMMIT 2015: Japanese operator NTT Docomo gave an update on its plans for its targeted 5G launch from 2020, which will be split into two phases – tagged 5G and 5G+.
In order to meet the ambitious timeframe, the company’s initial deployment will centre on enhancements to LTE and the deployment of some new radio access technologies, Takehiro Nakamura, VP and director of RAN for the company, explained. “But I think that in 2020 it will be very difficult to use the higher spectrum bands. So maybe below 6GHz is the main target.”
This will in part be affected by the availability of higher frequency spectrum assigned for mobile use. While research is under way into various options, it is still early days, and allocations are unlikely to take place internationally until after the World Radiocommunication Conference in 2019.
There are some challenges with this approach, Nakamura said. “Below 6GHz there is a risk that we can’t use enough spectrum. If we cannot have enough spectrum, we have to consider use of the unlicensed band, with the ongoing discussion of LAA (licence assisted access) technologies.”
With the availability of new bands after 2020, what NTT Docomo is referring to as 5G+, “a full package of 5G hopefully can be deployed around 2022/2023”.
In order to meet its 2020 target, Docomo will need to work with early versions of standards – for example while the ITU-R has a late 2019 timeline for its IMT2020 specifications, “for Docomo this is too late”.
“We want to have a stable specification for 2020 deployment no later than the end of 2018,” Nakamura said, with the caveat that “5G technologies should have forward compatibility to 5G+, and also 5G+ should consider backward compatibility with 5G technologies”.
And the early deadline also means that one of the focus areas of 5G development – low latency – may take a back-seat. “Our primary requirement is mobile broadband, so in 2020 deployment we will mainly focus on the higher data rate and higher capacity. But in the later stage we should focus on the other aspects, such as the low latency,” Nakamura said.
Speaking in the closing session of what is the last LTE World Summit (it has been renamed 5G World for 2016), the Docomo man touted a collaborative approach to 5G. “Of course, we can provide information and experiences of the introduction and 5G launch to other operators, other countries, other regions, so that 5G can spread very smoothly all over the world. That’s our hope”.
“The European situation is a bit different, I know. But I really want to have a common understanding, and a common target, to deploy some kind of 5G system around 2020, together. 5G is not only a new radio, but also an enhancement of LTE, and enhancement of LTE is very essential for everybody, not only Japan, but also Europe,” he said.