Engineering news
The majority of today's trains in the UK and Europe that offer a WiFi service to passengers do so through a standard 3G or 4G mobile broadband. But Andrew Longyear, transportation architect at Cisco Systems, said that it was not fast enough for higher speed connections. He spoke to Professional Engineering at Railtex, a trade-show for the rail industry at the NEC in Birmingham.
Current systems using mobile data can only reach a maximum speed of 300Mb/s. A recent report The Connected Train, published by Atos in 2014 and a theme of several seminars at the conference, estimated that the proliferation of smart devices would mean that each passenger on a train will require a 8Mb/s WiFi connection in future.
Longyear is working on a government-funded project called SWIFT (Superfast Wireless in-train for Future Travel), designed to demonstrate the possibilities of a constant high-speed connection throughout an entire train journey, as well as to explore the technology required.
It's important not only to provide fast WiFi on the train but also to get the bandwidth off the train, said Longyear. "It's not just passenger WiFi, although that's the main thing driving this. It's also looking at things like monitoring, looking at passengers, looking at other use cases like smart ticketing that might be driven by the train operators,” he added.
The target of the project initially was to reach an upload and download speed of 100Mb/s, but after 18 months Cisco have more than exceeded that in testing - with an “unheard of” speed of 1Gb/s looking possible, according to Longyear.
The solution Cisco have arrived at involves a network of small, lightweight trackside transmitters - either attached to existing masts, or new ones, and placed every 2.5km along the track. The system has been in development for 18 months, and is being tested at Long Marston - a rail depot near Birmingham that features a short loop of track.
The trains can only travel at up to 35mph on this test track, but according to Cisco’s consulting systems engineer Steve Matthews, that’s more than enough. Also speaking at Railtex, he said: “People think high-speed is a challenge, but actually it’s probably less of a challenge than going slowly from what we’ve seen so far”.
As well as antennas at trackside, there are also antennas at the front and back of the train, and cabling to connect to routers in the individual carriages. It’s hoped that new technology will be able to determine exactly where someone is sitting in a train - whether they’re sitting in standard class or first, for example - to charge them automatically or provide exclusive multimedia services. The SWIFT project has been able to conduct voice calls over WiFi, and stream video while in motion.
One of the challenges to overcome has been how to handover the connection between different types of signal source. At the test-track in Marston, there’s a length of track where the data is provided by the new trackside technology, plus a section where connectivity is provided by a traditional WiFi router to emulate the train being in a station. Finally, there’s a part of the track where the test train - a 1961 model Longyear calls “the oldest train with the fastest WiFi” - must rely on a traditional mobile signal. Nailing the handover is vitally important for the project to succeed.
“Ideally passengers would like a seamless experience whilst travelling, just as in the office or at home,” states The Connected Train report. “This means the ability to not only process their email and meeting requests, but to also consume media and engage with social networks… On commuter routes you often see passengers using their computers or tablets at the same time as other devices. We expect that each passenger will need to be able to access 8 Mb/s in order to achieve the experience they desire.”
In-train wifi has generally been non-existent, or so slow that it might as well not exist. Thanks to clever engineering and software, that could be about to change.