Japan's NTT DoCoMo has teamed up with a number of major vendors to conduct 5G trials in an actual-use environment in Tokyo, achieving data transmission rates of over 2Gbps.
The operator worked with Huawei, Nokia Networks, Samsung, Ericsson and Fujitsu on a trial at a high-rise complex in the city.
The trial used millimeter-wave extremely high frequency 70-GHz signals for the data transmission.
DoCoMo said this was the first time 5G data transmission had been achieved in a commercial complex due to previously unsolved problems involving base stations being out of line of sight and diffused signal reflections.
The operator and its partners overcame these problems with by using two new technologies - beamforming, which focuses radio waves in a specific direction, and beam tracking to control this direction based on to the mobile device's location.
DoCoMo worked with Samsung in November to conduct a separate 5G trial in South Korea's Suwon-city involving using 28-GHz signals to transmit data at rates of over 2.5Gbps in a vehicle traveling at 60km/h.
The operator has also recently collaborated with Ericsson, Fujitsu and Huawei on trials of technologies expected to become components of the 5G standard, including multi-user multiple-input multiple-output (MU-MIMO) technology.