A global first; Nanjing’s ambition in the field of 5G interconnectivity for all has recently taken another step toward being a reality, with the city becoming the first in the world to have 5G service availability across its entire network. Or has it?
China Daily made the boast on Saturday, 31 October, saying, “Subways in Nanjing, Jiangsu province, now have the most 5G service availability in the world, the city’s subway operator and the Nanjing branch of China Mobile announced at a news conference on Thursday”.
The Nanjinger on the other hand, ever skeptical, got interested and set off to verify the accuracy of the claim.
Turns out it comes with a caveat. This correspondent yesterday evening looked extensively around Cuiping Shan station on Metro Line S1 and found no evidence of 5G base stations installed on the station’s upper level, ie at ticketing and the security check.
Downstairs, however, it’s a different matter. All along the platform length, miniature 5G base stations have indeed been installed, positioned on either side of the platform and affixed to the station’s false ceiling.
It’s a similar story over at Nanjing South Railway Station, where The Nanjinger took note of the 5G base stations installed on the ceilings at platform level on both Lines 1 and 3.
5G signals rely on line of sight for transmission and reception; ie any one smartphone must be able to “see” a 5G base station in order for the network to function.
As a result, Cuiping Shan Station has eight 5G base stations installed, each covering a different part of the platform, and positioned to best avoid the station’s supporting pillars, so that every part of the platform may be within sight of a base station.
Likewise on the trains themselves, where the challenge of installing 5G becomes formidable, if not financially prohibitive.
To realise this would require thousands of base stations on the roof of every tunnel across the Nanjing Metro network, signals to and from which would be passed between antennas on the train’s roof across its length, which would then relay signals via repeater base stations positioned inside the carriages of the train.
So while the Nanjing Metro may well indeed be the first in the world to have 5G service available at every station on its network, we will for the moment have to content ourselves with only being able to download movies while waiting for a train.
At least we’ll have something to watch on the commute.
