The test was conducted in Fuji Speedway on the 7th of November. All connections were on the 28GHz band which the popular band for 5G tests in the US. Japan also considers designating the 28GHz spectrum for commercial 5G networks in Japan.
Stabile connection while moving fast was achieved with the massive multiple-input multiple-output (MIMO) technologies. This features a form of beamforming which concentrates radio waves in a specific direction and beam tracking. This means that the data beams can be adjusted according to the fast-moving device’s location. Previously, data transfer to a fast-moving device was not possible because of the large path-loss of high frequency signals. According to DoCoMo, no one had achieved a successful wireless data transmission to a fast-moving device until now.
In the US however, much of the tests done were focused on fixed wireless instead of mobility. The CFO of Verizon, Fran Shammo said that the initial pilot 5G connections will be all about fixed wireless, not mobility. Later this was backed by AT&T.
Earlier, in October DoCoMo also conducted a fixed data transmission trial with Huawei. This test was conducted in the Minato Mirai 21 waterfront of Yokohama. The test field measured 100.000 square meters which is equivalent to 12 soccer fields. Here, 23 mobile devices connected simultaneously and achieved a cumulative 11.29Gbps of data throughput and latency below 0.5 seconds. This was all done using the 4.5GHz frequency band.
