Rail Industry Focus

The switch to GSM-R

Network Rail’s FTN/GSM-R project has hit the latest in a series of major milestones, and over the next 18 months most of the rest of the country will become operational. Adam Hewitt reports.

On December 31, 2012, the old analogue NRN system (National Radio Network) was switched off in the south of England, as operators switched over to using GSM-R (Global System for Mobile Communications – Railway).

It will gradually replace the more advanced CSR (Cab Secure Radio) too – GSM-R is much more modern, with digital quality, no interference, and the capability for data communications.

The infrastructure for the new track-to-train radio system is mostly in place already – the underlying FTN (Fixed Telecommunications Network), as well as 2,200 GSM radio masts along the entire network, ranging in height from five metres up to 29.

The project, the total cost of which including FTN, GSM-R and the cross-industry work is £1.839bn, has had a number of drivers. These included meeting European regulations, improving network resilience, the fact that the old NRN system was going to run out of capacity and there was a requirement from Ofcom to release the spectrum in the south of England, and preparing for future communications applications, from ticketing to signalling.

GSM-R addresses the requirements of several recommendations from reports into accidents, including the Cullen Report on Ladbroke Grove, which said there needed to be one unified system of signaller to train driver communications. The overall case has been made in terms of performance, however, with safety benefits being an added plus, for example by lowering the risk of accidents or injury from people getting in and out of cabs to use trackside phones.

GSM-R is only a 2G system, as the specifications have been around so long and the European mandating process was so complex. But it features five key improvements on previous systems (a lot of the extra features are also available on the public mobile phone networks, which use GSM, but just aren’t turned on). These are:

i) Location dependent addressing (this allows the ‘call my signaller’ function, for example, to route it to the right signaller along different parts of the track)
ii) Functional addressing
iii) Group call
iv) Broadcast calls (similar to group calls, but no-one can respond)
v) Prioritisation and an ‘All Trains Stop’ button (there are five levels, with the highest clearing any other call if the ‘big red button’ is pressed, giving every other train in the area a ‘stop’ message. The equivalent red button process with the previous NRN radios was slower and involved voice communications with the controller.)

Deciding on the protocols around the red button – exactly which services should be stopped, especially when geographically nearby but operationally very different routes might be affected – has been a balancing act. The UK radio equipment also has an extra feature not found in Europe: the yellow button, for less urgent emergencies that don’t require the stopping of the railway.

Resilience

Network Rail’s Trevor Foulkes, formerly the telecoms programme engineering manager and now a senior programme manager, who has had a long career in railway telecoms, said: “We try to make our network resilient. There have been cases in the past where derailments have taken out radio sites, and also cut the cable – [meaning] the very things you’d want to use to stop other trains weren’t actually available.

“So we took quite a lot of effort to ensure that FTN cabling, and the way we ran it and configured it, would be in rings so that the systems would keep running even when we cut cables or had derailments that cut them, or power failures, or cable theft. We’ve had all of that.

“The maintenance people can see any bit of kit in the FTN network or GSM-R, zoom right in and say ‘this card’s failed’, or ‘this input on this card has failed’. They can understand the impacts on operations, and go to the site and take the right card with them. Because we use the same kit everywhere, it’s much easier now.

“We designed it so they don’t have to dash out in the middle of the night – they can go in the day when it’s safer. It also means people aren’t having to fix things absolutely immediately – it can be done when there are no trains running, for example.”

Performance

The performance improvements haven’t necessarily been immediate, however, partly due to staff having to get used to new features. Network Rail’s Dave Palmer, programme sponsor for the FTN/GSM-R project, said it had been a “mixed story”, explaining: “It has had performance impacts, and adverse impact has been felt a few times.

“But predominately the pendulum has swung the other way, with significant improved recovery [times] after incidents, for example.”

The biggest benefit has come for those who had previously used NRN, he explained – those using CSR would see fewer benefits by comparison, as it is already a more modern system.

A study carried out at the beginning of the programme found a likely reduction of 3-4% in overall delay minutes as a result of radio failure. But that didn’t capture the secondary performance benefits, which Network Rail says are substantial, but very hard to quantify.

The infrastructure

Underlying GSM-R is FTN, “the glue that holds everything together” as Network Rail puts it. 15,015km of fibre-cable is installed, and virtually all the physical infrastructure is in place, though not all of it is live yet – some is coming online at the same time as GSM-R commissioning in that area (see panel).

It replaces services that previously had to be bought-in, following the long and winding history of British railway telecommunications infrastructure since the sell-off of British Rail Telecommunications to Racal in the mid- 1990s, which through a series of sales and mergers became Thales Telecommunications Services, while Global Crossing (bought up by Level 3 Communications in 2011) owned other parts of the infrastructure.

Palmer said that relying on external third parties was a vulnerability, as Network Rail lacked control of its own destiny.

The other important infrastructure requirement was installing the thousands of radio masts, which required a huge consultation and stakeholder management process, although most of them could be built under Permitted Development Rights. Even so, Network Rail undertook to ensure residents, councillors, MPs and bodies like Natural England and English Heritage were aware of what was being done.

Once the infrastructure was installed and following tests in Strathclyde and with the Cambrian ETCS trial, GSM-R could then start going live on the main network.

The roll-out of GSM-R

As of March 2013, 7,231km were operational, meaning the project was 48% completed. The coming go-lives are as follows:

End of June 2013 – 7,494km operational (roll-out 50% complete). Cardiff Re-Signalling Phase 2.
Start of July 2013 – 8,789km (58%). ECML and WCML complete.
End of July – 9,510km (63%). North west England and south west Scotland.
End of September – 10,609km (70%). Remainder of Wales.
End of October – 12,657km (84%). Remainder of Scotland and East Midlands.
Mid-December – 13,548km (90%). Remainder of Midlands.
Start of 2014 – 13,666km (91%). Merseyrail.
End of January 2014 – 15,108km (100%).
Filling in the gaps in northern England.

NRN will be switched off in the north by the end of 2015, and although there is no formal deadline to turn CSR off, Network Rail said it was hoping to do so by the end of this year.

Some TOCs have more to do than others in preparation for using the new system – Southeastern and Merseyrail, for example.

But overall, Palmer said, the benefits are so substantial that the TOCs “are all looking at having it at the earliest possible opportunity”.

Network change and working with the TOCs

Project manager Gary Porter noted that this was much more than a Network Rail project – it had to involve the ORR, DfT, RSSB, ATOC, all the TOCs and the FOCs. “A lot of what has to be done has to be done by our customers,” he said.

Dave Palmer explained that the introduction of GSM-R was a huge challenge because of this, and because of the rules around network change under the Network Code, with the process of formally notifying TOCs, getting their comments and potentially sorting compensation and other arrangements.

He said: “We were placed in a very complex situation, with a national change of network from one radio system to another, affecting every individual operator and their vehicles, meaning all of their drivers needed to be trained, their maintainers needed to be trained, etc.

“You can’t swallow an elephant in one bite. Trying to get a national agreement with every operator signed off on it before we started on this proved to be not just a virtual impossibility but a real impossibility.

“So two years ago, we had a huge challenge. We were wondering how we would get through this, as was the rest of industry. So we had to reconsider what the implications and requirements of the Network Code actually were.

“It forced us to work very closely and collaboratively with the operators – that was the only way to solve this particular problem, as otherwise we were looking at stalemate, a situation where commercially, Network Rail and the train operators could not converge. Train operators were not going to commit themselves to something until they were certain of every last detail.

“We created a staged process, outside the requirements of the Network Code, and train operators and ourselves worked together to work up this process. It split the country up geographically and in operator layers over that geography, such that we could reach agreements with individual operators in a manner that didn’t compromise the protections that the Network Code offered other operators.

“We took that proposal, jointly with the operators, to the ORR, and got their agreement, in the middle of 2011.

“We got this process working, even though it was technically outside the Network Code.

“The real success story is that not only did we get it to work, and it’s supported every operational introduction of GSM-R since that date, but also that it’s also being talked about as the way of doing programmes with this level of complexity and that are all-embracing in terms of operators in the future, such as ERTMS.”

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