NTT DoCoMo and Fuji Television Network working in collaboration to create a 5G network by 2020 in Japan. But you don’t have to wait until 2020 to try the high-speed mobile internet network. From 2017 June (planned, not fixed) you can try the 5G network in Tokyo and Odaiba districts with the compatible devices.
DoCoMo also working on to create a “5G Trial Website” where you can try what 5G means in the mobile communication. Details will be published later about this project.