Yesterday was a big deal for high-speed trains in China. Not only did it mark the first trial operation of a real train on the Yangtze River Shanghai-Nanjing High-speed Railway, it also heralded in an era for continuous 5G connectivity for passengers thereon.
But there are a few catches, of course. Before that, the headlines today on media across the Yangtze River Delta are dominated by the commencement of trial operations. Yesterday, it was the G55301 service from Nanjing South Railway Station to Taicang Station which brought us to within 1 month of being able to experience the new route for ourselves.
The line stands out for it being many firsts, not least among which the 5G connectivity that is being touted, together with the technological innovations which have made it possible. These were first advertised by the Jiangsu Provincial Department of Transportation in February of this year, as this publication reported at the time.
When it comes to 5G, there are two challenges. 5G signals, being of high frequency, don’t penetrate much, except perhaps the leaves of trees. So inconvenient stuff along railway lines, such as stations, get in the way and block the signals.
Then there is the range of 5G, typically 1.6 to 5 kilometres, but that’s just for the low and mid-band spectrum traffic, i.e. that not significantly faster than 4G on a good day. The really fast 5G really doesn’t travel far, and ideally you need to be, like, the only one on the network if you are to “download a movie in 4 seconds”.
So realising this on a train hurtling from Nanjing to Shanghai at north of 300 km/h is a challenge. And one illustrated best by that encountered on the Gehu section of the Changzhou Super Bridge on the Yangtze River Shanghai-Nanjing High-speed Railway.
That’s 8.5 kilometres across open water; no 5G base station in sight. Engineers for the new line solved this by literally putting the base station in the track.
The main line of the Yangtze River Shanghai-Nanjing High-speed Railway has a total length of 275.174 kilometres, and to realise that 100-percent 5G connectivity, 64 communication towers were newly built.
According to the Yangtze Evening News, there were also a total of 1,462.364 kilometers of fiber-optic cables installed to ensure both the trains’ safety at high speeds and passengers’ fast and free Internet access.
