The outdoor trials used frequencies in the 28 GHz band
Japanese firms Mitsubishi Electric Corporation and NTT DoCoMo announced they have achieved what it claims to be the world’s first 5G mobile telecommunications proof of concept (PoC) for 27 Gbps and 25 Gbps maximum throughputs via one mobile terminal over communication distances of 10 meters and 100 meters, respectively, using the 28GHz radio frequency.
The demonstration was conducted during joint outdoor field trials using 28 GHz-band, massive-element antenna systems and 16-beam spatial-multiplexing technology with 500 megahertz bandwidth.
The trial took place in Kamakura, Japan, from September 10 to 28.
Antennas installed on the wall of a building directed beams to mobile-terminal antennas installed on the rooftop of a vehicle, the two companies said.
The partners also said that they expect to conduct trials using 28 GHz band in multipath-rich environments in the coming months.
In February this year, Mitsubishi Electric announced that it had developed 16-beam spatial-multiplexing technology consisting of eight analog, front-end processing, low-power units to form 16 beams and a multiple-input multiple-output (MIMO) digital processing algorithm to reduce inter-beam interference.
“Conventional 4G spatial multiplexing technology has limited multiplexing order, so Mitsubishi Electric and DoCoMo developed beamforming technology in an analog domain and inter-beam interference reduction technology to suitably separate overlapping beams with digital signal processing at the base station. The result is 16-beam spatial multiplexing, which has been unachievable with 4G,” the Japanese companies said in a statement.
“The developed beamforming technology enables beams to track a mobile terminal by switching the pre-set beam. The inter-beam interference reduction technology estimates the channel at the base station and controls the transmitting signal to adaptively reduce inter-beam interference as channel conditions over time. Together, the two technologies enable 16-beam spatial multiplexing in outdoor mobile environments.”
Japanese telecom operator NTT DoCoMo plans to launch pre-commercial 5G services in September 2019, the carrier’s president and CEO, Kazuhiro Yoshizawa,recently said during a conference call with investors and analysts.
Yoshizawa also said that the company aims to launch commercial 5G services across Japan by mid-2020. He also said that customers will be able to experience 5G services during the Rugby World Cup next year.
NTT DoCoMo has been adding partners to its 5G Open partner program, through which it aims to create 5G-based solutions. The program currently has 1,800 partners and expects to end 2021 with 5,000 partners, the executive said.
NTT DoCoMo has been carrying out a number of trials in the 5G field, mainly with Chinese vendor Huawei. The two companies had announced a collaboration with Tobu Railway to trial a millimeter wave system at Tokyo Skytree Town, as part of a broader push for field trials being advocated by Japan’s communications ministry.
DoCoMo and Huawei said the Tokyo trial was conducted with the main aim of researching technical conditions to use the 28 GHz band and other candidate spectrum for 5G in dense urban areas.
Earlier this year, Finnish vendor Nokia secured a contract with NTT DoCoMo to provide next-generation equipment for the operator’s future commercial launch. Under the deal, Nokia will support NTT DoCoMo’s commercial operation in Japan by further enhancing existing baseband units and integrating its 5G New Radio-based AirScale hardware in the network.
