There’s Wi-Fi at the end of the tunnel
Date: 29th June 2016
Topic: Monthly Features
Author: Laurence Doe
Technology: Public networks, Wi-Fi
Tags: small cells, EE, Real Wireless, Wi-Fi, railway communications, tunnels, railways, Cobham Wireless, Trains, Rail
It’s rare to find somewhere, either indoors or outside, where internet access is unavailable. The move towards an increasingly mobile workforce has been enabled by both the growth of Wi-Fi hotspots and the rapid adoption of tablets, smartphones and laptops.
And our need to be glued to a screen doesn’t stop when we’re travelling. “We’re seeing high interest in Wi-Fi calling, location- based services, asset tracking and proximity- based services, which are designed to improve business productivity and meet the need for people to be able to work from anywhere at any time, securely,” says Stu Higgins, head of digital impact at technology company Cisco UK and Ireland.
“We have also seen this demand in the area of connected transport as commuters need to be able to do business tasks on the move.” He sees the public’s desire for increasingly connected cities and connected transportation as what’s driving the need for a supportive Wi-Fi infrastructure.
“Users expect a seamless experience,” Higgins explains. “As application demands and video consumption increase, a fast, secure and robust infrastructure can mean the difference between success or failure for pleasing customers such as train passengers.”
To help meet this demand the UK is about to overhaul its train network connectivity. Over the next 12 to 24 months the government is planning to obtain commitments from a significant number of train operators, with both new and existing franchises signing contracts with equipment suppliers and MNOs to improve connectivity on their services.
Trains’ Wi-Fi challenge
“There’s a lot of areas where passengers want to have communications and connectivity,” says Anthony Sutton, coverage sales director at Cobham Wireless, while presenting at Cobham’s Going Underground event. This can range from business commuters requiring [access to] their emails to tourists using social media and other services to enhance their discovery experience.
“When they’re going through areas with no coverage they become isolated from their network, but they’re used to having communications wherever they go,” adds Sutton.
He can identify many factors that are inhibiting connectivity on our railways. These include not-spots where no connectivity exists because there is no macro layer coverage from the network operators or there are problems with capacity.
Another problem that Sutton highlights is that as train operating companies evolve their fleets they have been using metalised films on the windows to improve solar reflection and keep heat out of the carriages. “But that works as a Faraday cage,” he explains. “So it actually stops the mobile phone operators’ RF signal from penetrating the train.”
The government will not get in industry’s way if it comes forward with some “great commercial deals”, says Gavin James, programme manager for digital and telecommunications services at the Department for Transport, while speaking at the event. Part of his role is to assess whether proposed connectivity projects are good value for money.
James wants business commuters to have access to a “mobile office” on major lines such as the West coast (going to tender in November) and East coast. “I think we should recognise that there’s not a one-size-fits-all solution for this. That’s something I’ve heard again and again from train operators.”
Virgin has said that it is on board with the government’s plans, along with East Midlands Trains, Stagecoach and First Group. Chiltern Railway has already partnered with EE to provide complete Wi-Fi coverage along all of its routes.
Fortunately, rail companies are “really alive to the fact that this is going to be the next big thing and you have to have this connectivity,” says James.
“The government does have a co-ordinating role but it’s always better if we can find a way of making those commercial relationships more direct, which I think is shown in that one example [EE and Chiltern Railway]. There will be more to come.”
The right tool for the job?
Wi-Fi serves as a licence-exempt platform to engage with customers, doesn’t require an operator to connect, is ‘plug-and-play’, and is also “dirt cheap”, says Oliver Bosshard, managing consultant at Real Wireless.
“All these things are in Wi-Fi’s favour,” comments Bosshard. “[However,] it’s unlicensed so it’s prone to interference and people could have their own hotspot on the train and interfere with the operator’s wireless access points.”
Bosshard also points out that Wi-Fi is based on CSMA technology (Carrier Sense Multiple Access). He adds that this is not suited for allowing the access points to deal with a train packed with passengers; where a lot of connectivity is being used for email, messaging apps and downloads by lots of people all at once.
“If you could support 100 Mbps of capacity, when you have a lot of people trying to access it all of a sudden the throughput of the access points drops to 10 Mbps. You have less capacity left and you share it with more people so the end user experience becomes very poor. That’s the problem with Wi-Fi.”
Bosshard says small cells would be a better choice in this scenario because they are based on LTE technology so they don’t suffer from this problem. However, some online commentators take issue with this stance, arguing that modern Wi-Fi technology can cope well with high density environments. One said that “80-100 people in a sealed metal box is child’s play for today’s Wi-Fi to handle”. Land Mobile contacted a company with expertise in in-train Wi-Fi deployments for further comment on this issue, but they were unable to provide it before we went to press.
Bosshard supports the government’s plans to connect passengers, and claim they’re “not bad in terms of what they’re trying to achieve, they’re just a little bit misguided”.
“It shouldn’t have this free Wi-Fi tag on it, we shouldn’t say it has to be Wi-Fi. That’s where I think they’re going wrong.” He feels that as everyone has heard of Wi-Fi this is one of the main reasons it has been chosen by the government as the technology of choice.
“It’s great if you run for politics and it’s great because everybody understands free Wi-Fi. But if you tell them what it requires, ‘we’re going to put small cells and repeaters on a train’, people say ‘what on earth are you talking about, we have no clue what this means’. Free Wi-Fi is easy. It sounds fantastic and is great for marketing.”
Bosshard says that the system will need to be able to pay for itself and the environment of trains, tunnels and cuttings will make deployment of the networks difficult. But another hurdle is the number of parties that will need to co-operate (see the diagram below).
“Mobile operators want to make money against it but [use of their networks] isn’t really going to go up. So we need to find a way to make it happen and the business model that works best. Not necessarily over-engineer it but create something that meets demand and makes all parties happy,” he concludes.
The challenges of ‘Wireless in Rail’ (for operations and passengers); credit: Oliver Bosshard
Changing track to LTE
At the event Mansoor Hanif, EE’s director of radio access networks, revealed the mobile network operator’s plans to provide the UK’s railways with a network capable of supplying passengers with 1 Gbps download speeds using LTE backhaul.
Hanif explains that EE is planning to implement this on one railway line next year, and should that be commercially successful the MNO will extend it to as many lines as possible prior to the arrival of commercial 5G networks.
As part of discussions with the Home Office EE may extend this project to the London Underground and Crossrail. It is developing a roadmap for the rollout of this network over the next three to four years.
The roadmap will investigate the use of:
- 4G backhaul over satellite
- Meshed small cells with in-band backhaul Delivery antennas on the trains with local LTE broadcast capability
- Mobile edge servers with on-board cache
- A macro site upgrade with 5CC LTE-A and 256 QAM – this is to tackle the 35dB penetration loss caused by the train’s materials
- Next-gen repeaters
- Leaky feeders.
EE has been using Gilat Satellite Networks, a provider of products and services for satellite- based broadband communications, in its trials. Through doing so EE has discovered that satellite backhaul will be able to act as a backup to the network’s small cells and macro sites when needed.
Hanif says EE is considering the use of unmanned aerial vehicles (UAVs) to help maintain the network and to act as relays. “Drones are already being used to survey and maintain the railway tracks,” he explains. “It’s a question of Ofcom then – whether we can experiment and allow [the UAVs] to supplement the coverage. It’s something that we’re going to pursue.”
Hanif adds that as far as user devices are concerned the technology is already here. He notes that Qualcomm’s Snapdragon X16 LTE modem can deliver speeds of one Gbps. As for in-tunnel coverage, macro sites at the end of each tunnel could provide sufficient coverage in short tunnels, but it all depends on tunnel length.
However, to achieve all of this a lot of trees growing near railway lines will need to be cut down as they inhibit mobile signals. On top of this the train carriages themselves cause ≥99.9 per cent loss of signal. This has made costly on- board repeaters essential. For these challenges to be met Hanif says that key players such as Network Rail, train operating companies (TOCs), systems vendors, government and MNOs must work together.
EE is working with some of the TOCs on specific lines and making commercial arrangements to help to provide Wi-Fi service on trains using the 4G network as a backhaul network. That’s now active for several lines and EE is looking for more partners and to speak with more TOCs. Turning to the backbone of EE’s network, Hanif explains that the MNO is rolling out 400 Mbps speeds with an extra carrier and it has plans to add three more carriers over the next two years. EE is looking to prioritise this for the rail networks.
The MNO believes it can get to five carriers by 2019 and with the right conditions that will deliver speeds of close to one Gbps. “We have the technology to roll out one Gbps, but we don’t have the consumer demand for it. It’s the railways that are asking for it,” says Hanif.
“It’s always been our aim that if we can get good quality VoLTE and data services up to 100 [Mbps] per link for backhaul working over satellite we want to use that backhaul for embarked solutions and trains are the perfect application,” he adds.
Hanif also gives an update on whether EE will be required to provide LTE coverage for the London Underground as part of its Emergency Services Network (ESN) commitments. The MNO was awarded the contract to deliver and run the ESN on 9 December 2015. As part of the contract EE will provide the UK’s emergency services with mobile broadband connectivity.
“We are supporting the Home Office in discussions around this. It [London Underground] wasn’t formally part of the ESN scope and discussions aren’t yet formalised as a change request,” he says. However, Hanif adds that London Underground could become part of EE’s scope for the ESN, as could Network Rail and Crossrail.
Hanif explains: “There are discussions to make it [Network Rail] part of our scope and we are constructively engaging to see what the best solution is for the Home Office, Network Rail, TfL and everybody else.”
“I know Network Rail gets a bit of flack about being difficult to work with in this area,” says the Department for Transport’s James. “I think it’s got a difficult operating environment, so I want to defend it a bit because it’s not easy to run a railway and say ‘we’re going to allow a load of people in to bolt a load of stuff there’.
“This is such a big ambition for ministers, there’s a real demand from passengers... Network Rail is really rising to this challenge and starting to develop plans about how it’s going to get suppliers onto its infrastructure and work this out,” he continues.
James adds that he’s felt “nervous” around what suppliers may be able to deliver. This has led to the government discussing the possibility of trials with Network Rail, with suppliers coming in to demonstrate equipment, speeds that can be achieved and reliability.
The next stop
“By 2018 there will be free Wi-Fi on 90 per cent of passenger journeys. By 2020 that’s virtually every train in the country,” adds James. However, he explains that the timing could be delayed depending on the rollout of new trains.
“We’ll leverage the Wi-Fi investment as much as possible, that’s just common sense if we’ve already made a commitment that we will get the rail industry to invest millions in Wi-Fi equipment on trains. We want to make sure it’s as good as it can be,” he adds.
James says that the government doesn’t want to dictate how the technology will work, but is instead allowing train operators – such as those on the West coast – to come forward with “innovative solutions”.
He touches on an outcome-based franchising model that could see operators lose money should the connectivity they offer to passengers fail to meet a required level. However, this level “is really hard to specify”, stresses James. He adds that such an arrangement would be a “big ask” given train operators’ inexperience in connecting passengers and the questionable reliability of feedback if the quality of connection was rated using a scale of one to 10
From what I heard at Going Underground it won’t be long before we’ll be able to indulge our passion for streaming video while riding the trains. While many of our traditions have been left by the wayside, taking the daily commute in complete silence while ignoring passengers we have known by sight for years looks like it’s only going to get easier.