NTT DoCoMo on Tuesday risked provoking snorts of derision among the assembled press at Broadband World Forum by discussing seriously the possibility of rolling out 5G in time for the Tokyo Olympics in 2020.
"It seems far-fetched but nonetheless we need to consider it," insisted Takehiro Nakamura, director of NTT DoCoMo's radio system design group, in a presentation on Tuesday.
5G is still in the conceptual stage and what it consists of depends on who is giving the presentation.
For NTT DoCoMo, 5G represents a 1,000-fold increase in access network capacity. This gain will be required to support the "multiple personal devices that will connect wirelessly" over the coming years, Takehiro predicted.
To achieve this huge increase, DoCoMo has proposed using large amounts of high-frequency spectrum coupled with massive MIMO (multiple-input multiple-output) technology, which significantly increases the number of aggregated antennas in the access network.
Based on the telco's own simulations, Takehiro claimed that a 30x capacity increase could be realised by using 100 MHz of 3.5-GHz spectrum delivered via 12 small cells. The same number of small cells using 400 MHz of 10-GHz spectrum could result in a 125-fold increase, he said. To get to the magic 1,000+ increase, Takehiro said 12 small cells using 1 GHz of 20-GHz spectrum, coupled with massive MIMO could help an operator reach that target.
However, using such high frequencies would mean that the benefits would only be experienced outdoors, he admitted.
"We should consider new radio access technologies to create the big gain needed," Takehiro said.
However, he insisted that 5G is something the industry should be taking seriously.
"2020 is not that far off," he concluded.