NTT DoCoMo outlines phased approach to 5G, 5G+

Well, it's never too early to plan for what comes after 5G, right? Japan's NTT DoCoMo shared an update on its plans for launching 5G in 2020, and it will be split into two phases, one termed 5G and another dubbed 5G+.

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," Takehiro Nakamura, VP and director of RAN for the company, told Mobile World Live.

"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."

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 was the last LTE World Summit--the name changes to 5G World in 2016--Nakamura 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."

One of DoCoMo's long-standing research partners, Ericsson, this week posted a video about 5G security. Eva Fogelström, Ericsson's head of security research, says Ericsson also foresees multiple stakeholders working together through joint research initiatives, consensus building and standards to set the security baseline for trustworthy and manageable 5G networks.

Some 25 years ago, when GSM systems were being developed, security was designed to protect connectivity--voice, and in later generations, packet data as well. The purpose was to gain users' trust and protect privacy and to safeguard the ecosystem in terms of charging. It's worked well, but 5G will also drive other requirements.

"The trust model for 5G needs to be defined," Fogelström said. For current mobile systems, the trust model is fairly straightforward, with a subscriber, a device, a home operator and a serving network operator. But as 5G aims to support new devices and new business models with new actors, the trust model will change.

SIM cards will still play a role, but there are new trends involving "bring your own identity," and with the Internet of Things and billions of devices, "we believe that the 5G ecosystem will benefit from a more open identity management architecture, allowing for different alternatives," she said.

For more:
- see this Mobile World Live article
- see this TeleGeography article
- see this Ericsson video

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