Japan is expected to be an early adopter in the 5G segment as local telecom operators are looking to start deploying the new technology around 2020.
NTT DoCoMo has been carrying out a number of 5G trials, mainly with Chinese vendor Huawei. The two companies recently announced a collaboration with Tobu Railway to trial a 5G millimeter wave system at Tokyo Skytree Town as part of a broader push for 5G field trials being advocated by Japan’s Ministry of Internal Affairs and Communications (MIC).
The partners said the 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.
NTT DoCoMo and Huawei previously completed a joint field trial for 5G mobile communications over a long distance using the 39 GHz mmWave band in Yokohama, Japan. During that trial, the downlink data transmission achieved a maximum speed of more than 2 Gbps on a testing vehicle, which was equipped with user equipment equivalent to a mobile phone.
In November 2016, NTT DoCoMo and Huawei carried out a large-scale field trial using 200 megahertz of spectrum in the 4.5 GHz band in Yokohama, Japan. During the trial, the companies said they witnessed network speeds up to 11.29 Gbps total and less than half-a-millisecond latency.
Finnish vendor Nokia recently secured a contract with NTT DoCoMo to provide 5G equipment for the operator’s future commercial launch.
Under the 5G deal, Nokia will support NTT DoCoMo’s commercial operation in Japan by further enhancing existing baseband units and integrating its 5G New Radio (5G NR)-based AirScale hardware in the network.
Meanwhile, rival operator SoftBank is also very active in the 5G field. The Japanese telco has recently inked a partnership with Huawei to demonstrate potential 5G use cases for its enterprise partners. A demonstration included real-time UHD video transmission using ultra-high throughput, remote control of a robotic arm using ultra-low latency transmission and remote rendering via a GPU server using edge computing. The real-time UHD video transmission demonstrated throughput of over 800 Mbps. Also, the remote control of the robotic arm demonstrated an ultra-low latency one-way transmission of less than 2 ms.
SoftBank said it is planning various experiments to study 5G technologies and aims to launch 5G commercial services around 2020.
In 2017, SoftBank had also worked with ZTE and Wireless City Planning to verify 24-stream space division multiplexing technology by using pre-standard 5G TDD massive multiple-input multiple-output technology on a commercial network in Nagasaki, Japan.
In this verification test, 24 terminals downloaded FTP data simultaneously at a rate of 956 Mbps on a 20 megahertz channel, the two companies said.
SoftBank has been also working with Ericsson in the execution of 5G trials in Japan. In September 2017, the two companies had announced plans to conduct a joint trial of 5G in the 4.5 GHz band in urban areas of Tokyo. This 5G trial included two new radios, virtualized radio access network and evolved packet core RAN, beamforming, massive MIMO functionality and support services.
KDDI has been also engaged with 5G trials, mainly with Ericsson and Samsung Electronics. In September 2017, KDDI and Ericsson inked an agreement to test a proof of concept in the 4.5GHz frequency band in a number of cities across Japan. Ericsson said that the 4.5GHz frequency band is one of the candidates for 5G in Japan.
KDDI and Ericsson said they were planning to carry out a large number of tests across a wide range of use cases in the 4.5 GHz and 28 GHz frequency bands, including interworking between 5G and LTE technologies.
In March, the Japanese operator and South Korea’s Samsung Electronics announced the successful completion of a field trial held in Okinawa Cellular Stadium, a 30,000-person capacity baseball stadium in Japan.
The trial, which used Samsung’s 5G end-to-end solutions spanning a virtualized core, virtualized RAN, 5G access units, and multiple prototype 5G tablet devices, showcased live feeds of 4K video content, downloaded and streamed simultaneously on 5G tablets that could utilize mmWave spectrum.
