The company worked with JR East, which runs trains in Greater Tokyo and the Tōhoku region, on one of the railway’s new Shinkansen test trains (pictured). The two companies ran the tests on the whole of the line between Tokyo’s Sendai station and Aomori, 575km away at the northern tip of Honshu.
On the trial, testers were able to download data at 500Mbps and upload data at 100Mbps, said NTT DoCoMo, using equipment that conforms to 3GPP standards for 5G.
Both the mobile operator and the railway company were worried that communication quality at high speed would be unstable due to influence of direct-path obstructions and the Doppler effect, which causes shifts in frequency.
“This is especially true in the case of 5G, which uses relatively high-frequency bands that are more sensitive to physical obstructions and the Doppler effect compared to lower frequency bands used in legacy mobile communication networks,” said DoCoMo.
The tests included handover between base stations and the transmission of high-definition video data, in trials on JR East’s Alfa-X(1) test train. “The trials confirmed that it will be possible to ensure stable mobile communication environments on high-speed trains for the delivery of high-value mobile services,” said DoCoMo.
In the tests, “highly stable communication at 100Mbps or higher was achieved over a distance of approximately 5km, confirming the possibility of practical, reliable communication”, said the phone company. “Successful handover was confirmed while maintaining data rates at 100Mbps or higher.”
The trials showed successful transmission 4K and 8K high-definition video data: “The advanced capabilities of this new technology are expected to open up a wide range of high-value services for customers travelling on high-speed trains,” said JR East.
