I've not seen a thing about this since, but something has been happening - indeed, quite a lot - if not quite as soon as they said (but then, this is the railway!).
First, there was a trial installation on the Island Line, which was reported as a success in spring 2021, as in
Blu's re-publishing of an article from Global Railway Review:
Using Blu Wireless’s 5G mmWave platform, which is suitable for infrastructure applications such as 5G backhaul and transportation, the solution has been successfully trialled at Network Rail’s Rail Development and innovation Centre (RIDC) and the Island Line on the Isle of Wight.
Covering ten miles of the Island Line, this implementation transmits signal from sophisticated trackside (DN) access points installed on poles. Complementary active on-train (TN) antennas installed on the front and rear of the train receive the ultra-high bandwidth via highly directional pencil beams. Real time control algorithms are used to maintain beam connection between the multiple DNs and TNs as the train progresses along the track and passes each DN. As a train approaches a trackside node, a pencil beam connects it with the antenna on the front of the train. The beam moves electronically to keep the connection as the train passes by, while the connection is also established with the antenna at the rear end of the train. This ‘make before break’ approach ensures there are usually multiple connects to the train and no breaks in the connection even when the train is travelling through a deep cutting, thus providing a consistent Wi-Fi experience for passengers.
If you want that in pretty pictures rather than long words,
there's a video about it too. That comes from "evo rail", a subsidiary set up within First Group to exploit the system. (Note: not Evo-rail which is an SSDDC (scalable sofware-defined data centre) from VMware.) The name Blu Wirelss seems to have vanished now.
But
today's news is from SWR» , and says:
South Western Railway, evo-rail, and Network Rail bringing new superfast Wi-Fi to train passengers- SWR customers will enjoy superfast Wi-Fi on-board SWR services from Basingstoke to Earlsfield
- The technology will cover over 70km of railway, in a first for the UK▸ mainland
- Full deployment is likely to complete and launch for customer use in early 2023
The rail-5G project to deploy superfast on-board Wi-Fi for South Western Railway (SWR) customers between Basingstoke and Earlsfield is progressing at pace. Engineers for the project by evo-rail and SWR, in partnership with Network Rail, have now installed the first series of rail-5G poles on the line between the stations on the South West Main Line.
It will be the first railway line in the mainland UK to deploy the industry-leading rail-5G technology for customer use. With over 100 trains already fitted to accommodate the solution, the technology will cover 70km of the SWR network.
Evo-rail, a telecoms company part of FirstGroup, has developed rail-5G as the first multi-gigabit internet solution built for the railways. Rail-5G can dramatically improve connectivity on trains, with the technology enabling the delivery of superfast continuous internet, at 50 times the current average speeds.
With rail-5G, passengers will be able to enjoy unprecedented levels of connectivity, similar to what they are used to at home or in the office, allowing them to stream videos, make video calls, download large files, and much more.
In terms of what it is physically, it's little boxes on poles beside the line up to 1 km apart but, as it works only on line of sight, in most places closer than that. And if it works, one train will still share bandwidth, but more of it - their example shows two radio links at 400
GB▸ /s each. Is that the limit? Probably not.